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Introduction. There are limited epidemiological reports of hemolytic uremic syndrome (HUS) in Latin America. Objective. To describe the frequency and characteristics of hospitalizations due to HUS in children aged 0 to 14 years. Methods. Descriptive study of secondary analysis was performed with data on hospitalizations due to HUS from healthcare institutions from Peru, 2015-2022. Results. Two hundred twenty-eight hospitalizations were registered, 52.2% were male, 88.6% were under five years old, and 11% were under one year old. The departments with more hospitalizations were Lima (133 cases) and Arequipa (46 cases). The institutions of the Ministry of Health (MINSA) and Social Security (EsSalud) reported 42.5% and 27.6% of hospitalizations. From 2015 to 2022, the incidence ranged from 0.42 to 1.13 cases/100,000 children under five years of age. Conclusions. Hospitalizations due to HUS were more frequent in children under five years of age and MINSA institutions., Introducción. Existen limitados reportes epidemiológicos del síndrome urémico hemolítico (SUH) en Latinoamérica. Objetivo. Describir la frecuencia y características de las hospitalizaciones por SUH en niños de 0 a 14 años. Métodos. Se realizó un estudio descriptivo de análisis secundario con datos de hospitalizaciones por SUH de instituciones de salud de Perú en el periodo 2015-2022. Resultados. Se registraron 228 hospitalizaciones. El 52,2% fueron varones. El 88,6% fue menor de cinco años y el 11% menor de un año. Los departamentos con más hospitalizaciones fueron Lima y Arequipa con 133 y 46 casos. Las instituciones del Ministerio de Salud (MINSA) y del Seguro Social (EsSalud) reportaron el 42,5% y 27,6% de las hospitalizaciones. Del 2015 al 2022, la incidencia varió de 0,42 a 1,13 casos/100 000 niños menores de cinco años. Conclusiones. Las hospitalizaciones por SUH fueron más frecuentes en menores de cinco años y en las instituciones del MINSA.

The syndrome of thrombotic microangiopathy (TMA) is a clinical-pathological entity characterized by microangiopathic hemolytic anemia, thrombocytopenia, and end organ involvement. It comprises a spectrum of underlying etiologies that may differ in children and adults. In children, apart from ruling out shigatoxin-associated hemolytic uremic syndrome (HUS) and other infection-associated TMA like Streptococcus pneumoniae-HUS, rare inherited causes including complement-associated HUS, cobalamin defects, and mutations in diacylglycerol kinase epsilon gene must be investigated. TMA should also be considered in the setting of solid organ or hematopoietic stem cell transplantation. In this review, acquired and inherited causes of TMA are described with a focus on particularities of the main causes of TMA in children. A pragmatic approach that may help the clinician tailor evaluation and management is provided. The described approach will allow for early initiation of treatment while waiting for the definitive diagnosis of the underlying TMA.

Introduction Atypical hemolytic uremic syndrome (aHUS) is a rare form of thrombotic microangiopathy (TMA) often caused by alternative complement dysregulation. Patients with aHUS can present with malignant hypertension (MHT), which may also cause TMA. Methods This analysis of the Global aHUS Registry (NCT01522183) assessed demographics and clinical characteristics in eculizumab-treated and not-treated patients with aHUS, with (n = 71) and without (n = 1026) malignant hypertension, to further elucidate the potential relationship between aHUS and malignant hypertension. Results While demographics were similar, patients with aHUS + malignant hypertension had an increased need for renal replacement therapy, including kidney transplantation (47% vs 32%), and more pathogenic variants/anti-complement factor H antibodies (56% vs 37%) than those without malignant hypertension. Not-treated patients with malignant hypertension had the highest incidence of variants/antibodies (65%) and a greater need for kidney transplantation than treated patients with malignant hypertension (65% vs none). In a multivariate analysis, the risk of end-stage kidney disease or death was similar between not-treated patients irrespective of malignant hypertension and was significantly reduced in treated vs not-treated patients with aHUS + malignant hypertension (adjusted HR (95% CI), 0.11 [0.01–0.87], P = 0.036). Conclusions These results confirm the high severity and poor prognosis of untreated aHUS and suggest that eculizumab is effective in patients with aHUS ± malignant hypertension. Furthermore, these data highlight the importance of accurate, timely diagnosis and treatment in these populations and support consideration of aHUS in patients with malignant hypertension and TMA. Trial registration details Atypical Hemolytic-Uremic Syndrome (aHUS) Registry. Registry number: NCT01522183 (first listed 31st January, 2012; start date 30th April, 2012). Graphical abstract

Introduction. We assessed the features of kidney injury in patients with different types of TMA during pregnancy, taking into consideration the fact that the acute kidney injury (AKI) that occurs during pregnancy or in the early postpartum period is main- ly caused by various types of thrombotic microangiopathies (TMA), and AKI itself is a serious obstetric complication with the risk of serious complications and mortality for both mother and fetus.Objective of the study. To study the features of nephropathy in different types of pregnancy-associated TMA.Materials and methods. The study included 313 pregnant women, women in childbirth and puerperas, of which 71 women had atypical hemolytic uremic syndrome (aHUS), 124 – HELLP syndrome, 70 – varying degrees of severity of PE, a group of patients with more rare causes of TMA was also identified: TTP, CAPS and sepsis (13 patients) and 45 patients for the control group. We assessed and compared the main clinical, laboratory and instrumental data, and assessed the outcome of labour. Also, histological examination of the kidneys was performed in five patients with aHUS.Results and discussion. The results of the study have shown that the most severe manifestations of TMA in the form of target organ injury and nephropathy are usually occur in patients with aHUS, where all women developed AKI, in some cases with the formation of chronic kidney disease. In the HELLP syndrome group, AKI was recorded in 39%, but renal function quickly restored. It was found that the very fact of the presence of AKI points to a more unfavourable prognosis not only for the patients themselves, but also for the child, being the main risk factor for perinatal death. The findings of urinary sediment tests and morphological evaluation indicate that the resulting ischemia of the renal tissue in cases of aHUS, HELLP syndrome and other types of TMA can lead to tubular necrosis as compared with PE. Our results suggest that it is AKI in HELLP syndrome that is the main risk factor for perinatal death. Alas, this relationship is difficult to trace in patients with aHUS, as all of them had AKI.Conclusions. Timely recognition of the AKI phenomenon in all cases of obstetric TMA can reduce the risks for both mother and fetus. Both the prognosis for mother and the prognosis for child depend on AKI, and timely therapy can lead to a regression of AKI phenomena and the complete restoration of renal function.

BACKGROUND: Gemcitabine is a broadly used chemotherapeutic agent that can cause a rare but life-threatening complication called thrombotic microangiopathy (TMA). Early recognition is crucial as therapy options are limited. CASE DESCRIPTION: We report the case of a 46-year-old patient with pancreatic adenocarcinoma who presented with severe anemia and thrombocytopenia as well as acute kidney injury. A diagnosis of gemcitabine-induced TMA was made. He became rapidly transfusion and dialysis dependent. Despite discontinuation of gemcitabine and treatment with high-dose corticotherapy as well as plasmapheresis, no improvement in both renal and hematological parameters was seen. Treatment with eculizumab was initiated. One week after the first administration, the patient no longer required packed cells nor platelet transfusions and one month later, dialysis could be discontinued. After five doses, treatment with eculizumab was stopped. Four months later, his serum creatinine was 1 mg/dL. CONCLUSIONS: This case report illustrates the promising beneficial effects of eculizumab in gemcitabine-induced TMA, both regarding transfusion dependence as well as improvement in renal function, thereby allowing further therapy options in patients with an active malignancy. ispartof: JOURNAL OF GASTROINTESTINAL ONCOLOGY vol:13 issue:6 ispartof: location:China status: published

Aim: It is aimed to describe clinical properties and outcomes of pediatric hemolytic uremic syndrome hospitalized in pediatric intensive care.Material and Method: Our study was intended as observatory and retrospective. Symptoms before PICU admission, interventions before PICU admission, time period before PICU admission in days were defined as pre-PICU findings. Glasgow Coma Score (GCS) at admission, Pediatric Risk of Mortality Score (PRİSM-III), laboratory parameters, medical treatments, extracorporeal treatments data was collected as PICU interventions. Outcomes were examined as days in PICU, days in hospital and survival.Results: Twenty-three patients were included into study. Before PICU admission more than half of the patients were treated with antibiotics. Twenty-two were suffered from diarrhea. 3 patients had non-bloody diarrhea. 3 patients had central nervous system involvement presented as seizures. Intravenous diuretics (86.9%) and oral antihypertensives (73.9%) were the most common treatments in PICU. Eculizumab treatment was required for 6 patients. All patients got fresh frozen plasma. Nearly all of the patients required erythrocyte transfusions (95.6%). If we evaluated renal replacement therapies, 2 (8.6%) patients needed CRRT and 12 (52.7%) patients needed IHD. Extrarenal involvement was spotted in 5 patients (21.7%). Most of the patients were survived (95.3%).Conclusion: Hemolytic uremic syndrome is an important clinic entity. Most patients’ blood pressure could be controlled with oral antihypertensive treatments. Antibiotic prescriptions to diarrhetic patients should be more cautiously. There should be transfusion protocols of clinics about HUS patients to prevent over transfusion., Amaç: Pediatrik yoğun bakımda yatan pediatrik hemolitik üremik sendromun klinik özelliklerinin ve sonuçlarının tanımlanması amaçlanmaktadır.Gereç ve Yöntem: Çalışmamız gözlemsel ve retrospektif olarak planlandı. ÇYBB'ye yatıştan önceki semptomlar, ÇYBB'ye giriş öncesi müdahaleler, ÇYBB'ye kabulden önceki gün olarak geçen süre ÇYBB öncesi bulgular olarak tanımlandı. Başvuruda Glasgow Koma Skoru (GKS), Pediatrik Mortalite Skoru (PRİSM-III), laboratuvar parametreleri, medikal tedaviler, ekstrakorporeal tedavi verileri ÇYBB müdahaleleri olarak toplandı. Sonuçlar ÇYBB'de gün, hastanede yatış ve sağkalım olarak incelendi.Bulgular: Yirmi üç hasta çalışmaya dahil edildi. ÇYBB'ye kabul edilmeden önce hastaların yarısından fazlası antibiyotik tedavisi gördü. Yirmi iki kişide ishal mevcuttu. 3 hastada kansız ishal vardı. 3 hastada nöbet olarak ortaya çıkan santral sinir sistemi tutulumu vardı. ÇYBB'de en sık uygulanan tedaviler intravenöz diüretikler (%86.9) ve oral antihipertansifler (%73.9) idi. 6 hastaya ekulizumab tedavisi gerekti. Tüm hastalara taze donmuş plazma verildi. Hastaların tamamına yakınına eritrosit transfüzyonu gerekti (%95.6). Renal replasman tedavilerini değerlendirirsek 2 (%8,6) hastaya CRRT ve 12 (%52,7) hastaya İHD'ye ihtiyaç duyuldu. Beş hastada (%21.7) böbrek dışı tutulum saptandı. Hastaların çoğu hayatta kaldı (%95.3).Sonuç: Hemolitik üremik sendrom önemli bir klinik antitedir. Çoğu hastanın kan basıncı, oral antihipertansif tedavilerle kontrol edilebilir. İshalli hastalara antibiyotik reçetesi daha dikkatli olmalıdır. Aşırı transfüzyonu önlemek için HÜS hastaları ile ilgili kliniklerin transfüzyon protokolleri olmalıdır.

Publisher Copyright: © 2022 Bai et al. Shiga toxin-producing Escherichia coli (STEC) infection can cause mild to severe illness, such as nonbloody or bloody diarrhea, and the fatal hemolytic uremic syndrome (HUS). The molecular mechanism underlying the variable pathogenicity of STEC infection is not fully defined so far. Here, we performed a comparative genomics study on a large collection of clinical STEC strains collected from STEC-infected pediatric patients with and without HUS in Finland over a 16-year period, aiming to identify the bacterial genetic factors that can predict the risk to cause HUS and poor renal outcome. Of 240 STEC strains included in this study, 52 (21.7%) were from pediatric patients with HUS. Serotype O157:H7 was the main cause of HUS, and Shiga toxin gene subtype stx2a was significantly associated with HUS. Comparative genomics and pangenome-wide association studies identified a number of virulence and accessory genes overrepresented in HUS-associated STEC compared to non-HUS STEC strains, including genes encoding cytolethal distending toxins, type III secretion system effectors, adherence factors, etc. No virulence or accessory gene was significantly associated with risk factors for poor renal outcome among HUS patients assessed in this study, including need for and duration of dialysis, presence and duration of anuria, and leukocyte counts. Whole-genome phylogeny and multiple-correspondence analysis of pangenomes could not separate HUS STEC from non-HUS STEC strains, suggesting that STEC strains with diverse genetic backgrounds may independently acquire genetic elements that determine their varied pathogenicity. Our findings indicate that nonbacterial factors, i.e., characteristics of the host immunity, might affect STEC virulence and clinical outcomes.

This study aims to review all empirical evidence regarding the effect of eculizumab on long-term outcomes in infection-associated hemolytic uremic syndrome.

Child abuse is a serious problem with its complex causes and tragic consequences, including medical, legal, developmental and psychosocial. Child sexual abuse is the most difficult to detect among child abuse types. It is an important public health problem that has been faced with serious difficulties in diagnosing and has not been appeared the greater part of it. Our case is about a two-years three-month-old girl. The patient was chosen as a case after evaluating suspected child abuse and haemolytic uremic syndrome, finding such as subcutaneous bleeding, and sexual abuse which is based on thrombocytopenic ecchymosis. Within importance of diagnosing findings of abuse, some diseases or lesions should be evaluated well in the differential diagnosis. In this study, it was aimed to draw attention to a case report that it is necessary to consider hematologic, gastrointestinal and some infectious diseases in the differential diagnosis of findings that evaluate false positive as sexual abuse.

A 3-year-old girl came to our attention for fever and upper respiratory tract infection associated with thrombocytopenia, non-immune hemolytic anemia, and acute kidney injury (AKI). Complete blood count and renal function slowly normalized, with no need for dialysis. She was always normotensive with valid diuresis; her neurological status also rapidly improved. Nasal swab turned out positive for influenza A H1N1; stool test was negative for Shiga toxin-producing Escherichia coli (STEC). The patient was treated with oseltamivir for 5 days with a favorable outcome. Association between hemolytic uremic syndrome (HUS) and H1N1 influenza is poorly reported in literature [1, 2, 3, 4]. The pathogenic role of the virus in causing HUS is still controversial and debated [1, 2, 3, 4]. In our patient, complement activity markers (serum C3 and C5b-9) alteration suggested a transient, virus-mediated complement activation.

Background Hemolytic uremic syndrome caused by invasive pneumococcal disease (P-HUS) is rare in children and adolescents, but accompanied by high mortality in the acute phase and complicated by long-term renal sequelae. Abnormalities in the alternative complement pathway may additionally be contributing to the course of the disease but also to putative treatment options. Methods Retrospective study to assess clinical course and laboratory data of the acute phase and outcome of children with P-HUS. Results We report on seven children (median age 12 months, range 3–28 months) diagnosed with P-HUS. Primary organ manifestation was meningitis in four and pneumonia in three patients. All patients required dialysis which could be discontinued in five of them after a median of 25 days. In two patients, broad functional and genetic complement analysis was performed and revealed alternative pathway activation and risk haplotypes in both. Three patients were treated with the complement C5 inhibitor eculizumab. During a median follow-up time of 11.3 years, one patient died due to infectious complications after transplantation. Two patients showed no signs of renal sequelae. Conclusions Although pathophysiology in P-HUS remains as yet incompletely understood, disordered complement regulation seems to provide a clue to additional insights for pathology, diagnosis, and even targeted treatment.

Prostate cancer can masquerade as just normocytic anemia and thrombocytopenia, thrombotic thrombocytopenic purpura (TTP), hemolytic uremic syndrome (HUS), or tumor lysis syndrome (TLS). We are reporting an intriguing case of metastatic prostate cancer which remained undiagnosed until the patient showed signs of tumor lysis syndrome (TLS), leading to urate nephropathy requiring urgent hemodialysis. Tumor lysis syndrome is an oncological emergency but an exceedingly rare complication in non-hematological malignancies, including prostate cancer. It is challenging to recognize features of TLS in a case such as this with an unknown diagnosis. In the case of an established diagnosis of malignancy, however, checking baseline renal function, uric acid, lactate dehydrogenase (LDH), potassium, and phosphate to monitor for TLS as well as considering urate lowering therapy can help prevent adverse outcomes.

An 86-year-old man returned to the UK from Spain with symptoms suggestive of gastrointestinal bleeding. He was found to have an acute kidney injury and thrombocytopenia. Further investigations identified the presence of a microangiopathic hemolytic anemia, supporting the diagnosis of a thrombotic microangiopathy. Differentials included atypical hemolytic uremic syndrome and secondary thrombotic microangiopathy. Thrombotic thrombocytopenic purpura (TTP) and STEC (Shiga toxin-producing E. coli) hemolytic uremic syndrome were excluded by a normal ADAMTS-13 and negative E. coli serology and stool PCR. The patient was treated with blood and platelet transfusions. He received eculizumab and hemodialysis whilst a screen for secondary causes was undertaken. Thrombotic microangiopathy was shown to be secondary to recurrence of prostate cancer, which had been treated 16 years previously. He later recovered his renal function and receives ongoing hormonal treatment for his prostate cancer.

We conducted a retrospective study on hemolytic uremic syndrome caused by Shiga toxin-producing Escherichia coli (STEC) in 96 adults enrolled in the cohort of the National Reference Center for Thrombotic Microangiopathies network in France during 2009-2017. Most infections were caused by STEC strains not belonging to the O157 or O104 serogroups. Thirty (31.3%) patients had multiple risk factors for thrombotic microangiopathy. In total, 61 (63.5%) patients required dialysis, 50 (52.1%) had a serious neurologic complication, 34 (35.4%) required mechanical ventilation, and 19 (19.8%) died during hospitalization. We used multivariate analysis to determine that the greatest risk factors for death were underlying immunodeficiency (hazard ratio 3.54) and severe neurologic events (hazard ratio 3.40). According to multivariate analysis and propensity score-matching, eculizumab treatment was not associated with survival. We found that underlying conditions, especially immunodeficiency, are strongly associated with decreased survival in adults who have hemolytic uremic syndrome caused by STEC.

Background Insulin-like growth factor-binding protein (IGFBP) 2 plays an important role in the regulation of cell adhesion, migration, growth, and apoptosis. This study aimed to investigate the clinical significance of serum IGFBP2 as a biomarker for disease activity and severity in hemolytic uremic syndrome (HUS) induced by enterohemorrhagic Escherichia coli (EHEC). Methods IGFBP2 production by human renal glomerular endothelial cells (RGECs) after exposure to Shiga toxin 2 (Stx-2) was investigated in vitro. Serum IGFBP2 levels in blood samples obtained from 22 patients with HUS and 10 healthy controls (HCs) were quantified using an enzyme-linked immunosorbent assay. The results were compared to the clinical features of HUS and serum tau and cytokine levels. Results Stx-2 induced the production of IGFBP2 in RGECs in a dose-dependent manner. Serum IGFBP2 levels were significantly higher in patients with HUS than in HCs and correlated with disease severity. Additionally, serum IGFBP2 levels were significantly higher in patients with encephalopathy than in those without encephalopathy. A serum IGFBP2 level above 3585 pg/mL was associated with a high risk of encephalopathy. Furthermore, serum IGFBP2 levels significantly correlated with serum levels of tau and inflammatory cytokines associated with the development of HUS. Conclusions Correlation of serum IGFBP2 level with disease activity in patients with HUS suggests that IGFBP2 may be considered as a possible indicator for disease activity and severity in HUS. Larger studies and additional experiments using various cells in central nervous system should elucidate the true value of IGFBP2 as a clinical diagnostic marker. Abbreviations IGFBP: insulin-like growth factor-binding protein; HUS: hemolytic uremic syndrome; EHEC: enterohemorrhagic Escherichia coli; RGECs: renal glomerular endothelial cells; STx-2: Shiga toxin 2; HCs: healthy controls; LPS: lipopolysaccharide; ROC: receiver operating characteristic; sTNFR: soluble tumor necrosis factor receptor.

Aim and objective To examine the clinical characteristics, indications, and complications of patients undergoing therapeutic plasma exchange (TPE) in our pediatric intensive care unit (PICU). Materials and methods Patients who underwent therapeutic plasma exchange between January 2018 and January 2020 in the PICU were included in the study. Demographic, clinical, and laboratory data of patients were obtained retrospectively from medical records. A venous catheter was placed into subclavian, femoral, or jugular veins. The number of plasmapheresis sessions for each patient was determined by observing the course of the disease and clinical improvement. Patients were monitored for vital signs during the plasmapheresis process. Complications directly associated with TPE were recorded. Results During the 2-year study period, 105 TPE sessions were performed in 25 patients (15 males/10 females). The median age was 84 months (6–204), and the median body weight was 32 kg (8–75). Renal disorders and sepsis were the most common group, and about 48% of patients were in these groups. The most common diagnoses were sepsis with multi-organ dysfunction syndrome in seven patients and followed by hemolytic uremic syndrome (five patients) and Guillain–Barre syndrome (three patients). Nausea (6.7%) and hypocalcemia (6.7%) were the most common complications of patients associated with the procedure. Premature discontinuation of the procedure were not seen due to complications. Complications were treated with symptomatic therapy. Conclusion TPE is an effective treatment that can be safely used for pediatric patients with developments in PICUs. Nevertheless, TPE should be performed by experienced staff at a specialized center to minimize the risk of complications. How to cite this article Özsoylu S, Dursun A, Çelik B. Therapeutic Plasma Exchange in Pediatric Intensive Care Unit: A Single-center Experience. Indian J Crit Care Med 2021;25(10):1189–1192.

International audience; BACKGROUND: The prevalence, prognostic role, and diagnostic value of blood pressure in immune-mediated thrombotic thrombocytopenic purpura (iTTP) and other thrombotic microangiopathies (TMAs) remain unclear. METHODS: Using a national cohort of iTTP (n = 368), Shigatoxin-induced hemolytic uremic syndrome (n = 86), atypical hemolytic uremic syndrome (n = 84), and hypertension-related thrombotic microangiopathy (n = 25), we sought to compare the cohort’s blood pressure profile to assess its impact on prognosis and diagnostic performances. RESULTS: Patients with iTTP had lower blood pressure than patients with other TMAs, systolic (130 [interquartile range (IQR) 118-143] vs 161 [IQR 142-180] mmHg) and diastolic (76 [IQR 69-83] vs 92 [IQR 79-105] mmHg, both p

Postsurgical thrombotic microangiopathy (TMA) is a complication associated with significant morbidity and mortality. Still, the pathophysiological underlying mechanism of postsurgical TMA, a diagnosis often overlooked in postoperative patients with acute kidney injury and thrombocytopenia, is largely unknown. Here, we report the case of a 56-year-old male that developed anuric acute kidney injury, Coombs-negative hemolysis, and thrombocytopenia after surgical aortic arch replacement. Massive ex vivo complement activation on the endothelium, a rare complement gene variant in C2, at-risk haplotype MCPggaac, and excellent response to therapeutic complement inhibition, points to the pivotal role of complement in the pathophysiology of disease. Moreover, the importance of a multidisciplinary team approach in (postsurgical) thrombocytopenia is emphasized.

Background Atypical hemolytic uremic syndrome (aHUS) is a rare, complement-mediated disease associated with poor outcomes if untreated. Ravulizumab, a long-acting C5 inhibitor developed through minimal, targeted modifications to eculizumab was recently approved for the treatment of aHUS. Here, we report outcomes from a pediatric patient cohort from the ravulizumab clinical trial (NCT03131219) who were switched from chronic eculizumab to ravulizumab treatment. Methods Ten patients received a loading dose of ravulizumab on Day 1, followed by maintenance doses administered initially on Day 15, and then, every 4–8 weeks thereafter, depending on body weight. All patients completed the initial evaluation period of 26 weeks and entered the extension period. Results No patients required dialysis at any point throughout the study. The median estimated glomerular filtration rate values remained stable during the trial: 99.8 mL/min/1.73m2 at baseline, 93.5 mL/min/1.73m2 at 26 weeks, and 104 mL/min/1.73m2 at 52 weeks. At last available follow-up, all patients were in the same chronic kidney disease stage as recorded at baseline. Hematologic variables (platelets, lactate dehydrogenase, and hemoglobin) also remained stable throughout the initial evaluation period and up to the last available follow-up. All patients experienced adverse events; the most common were upper respiratory tract infection (40%) and oropharyngeal pain (30%). There were no meningococcal infections reported, no deaths occurred, and no patients discontinued during the study. Conclusions Overall, treatment with ravulizumab in pediatric patients with aHUS who were previously treated with eculizumab resulted in stable kidney and hematologic parameters, with no unexpected safety concerns when administered every 4–8 weeks. Trial registration Trial identifiers: Trial ID: ALXN1210-aHUS-312 Clinical trials.gov: NCT03131219 EudraCT number: 2016-002499-29

Hemolytic uremic syndrome (HUS), one of the forms of thrombotic microangiopathy, is a severe emergency with non-immune (Coombs negative) anemia, thrombocytopenia and acute renal injury. HUS is heterogeneous, and its most common form, the typical HUS, is associated with Shiga toxin (Stx) producing bacteria, such as Escherichia coli, Shigella dysenteriae, and Citrobacter freundii. Less frequent is HUS, caused by a neuraminidase producing streptococcus (pneumococcal HUS). The most uncommon form is the atypical HUS, which is a genetic orphan disease associated with an abnormality in the regulatory protein of the complement system. HUS has a fairly high mortality rate, amounting to 10–15% on average. The long-term outcomes of HUS depend on its type, as well as on the degree of the primary body tissue damage. According to the data from Novosibirsk Children's Municipal Clinical Hospital No 3 from 1991, 44 cases of HUS in children have been identified. Complete recovery, without any residual abnormalities, was registered in 25 children (56.8% of the cases). Nine children (20.5%) developed chronic kidney disease and 10 (22.7%) of all HUS cases were fatal. Early diagnosis, as well as the identification of pathogenetic mechanisms, is the basis for adequate therapy and outcome prediction. Campylobacter may be one of the causative agents of HUS. Despite new cases of Campylobacter-associated HUS being registered in the world, the very possibility of HUS induction by this pathogen and its pathophysiology are currently unclear. There is no convincing evidence for both Stx and the neuraminidase-related mechanism of HUS in Campylobacter infections. Given the high incidence of autoimmune disorders like Guillain-Barre syndrome and reactive arthritis in Campylobacter infections, it is currently impossible to exclude an autoimmune mechanism of HUS in these diseases. Thus, the role of Campylobacter, as a new potential bacterial agent of HUS, as well as the pathogenesis of such conditions in Campylobacter infections, requires further study.

Hemolytic uremic syndrome (HUS) may occur late after the onset and improvement of gastrointestinal tract symptoms. Clinicians need to carefully monitor for the onset of HUS, even if the patients have few symptoms.

Background The complement factor H antibody (CFH-Ab)–associated hemolytic uremic syndrome (HUS) forms a distinct subgroup within the complement-mediated HUS disease spectrum. The autoimmune nature of this HUS subgroup implies the potential benefit of a targeted immunosuppressive therapy. Data on long-term outcome are scarce. Methods This observational study evaluates the clinical outcome of 19 pediatric CFH-Ab HUS patients from disease onset until their 5-year follow-up. Results All but one relapse occurred during the first 2 years, and patients who had no relapse within the first 6 months were relapse-free until the end of the observation period. Kidney function at disease onset determines long-term kidney function: all individuals with normal kidney function at disease onset had normal kidney function after 5 years, and all patients with reduced kidney function at onset had impaired kidney function at the last follow-up. Level of CFH-Ab titer at disease onset was not correlated with a higher risk of recurrences or worse long-term outcome after 5 years. Resolution of CFH-Ab titers after 5 years was common. Conclusions CFH-Ab HUS patients have a varied overall long-term course. Early relapses are common, making close surveillance during the first years essential, regardless of the initial CFH-Ab titer.

The role of the lectin pathway (LP) of complement has not been explored in the thrombotic microangiopathies (TMA). We examined levels of MASP2, the effector enzyme of the LP, in three major forms of TMA and assessed the effect of the anti‐MASP2 human monoclonal antibody narsoplimab on TMA plasma‐induced activation of caspase 8 in microvascular endothelial cells. MASP2 levels were highly elevated in all TMA patients versus controls. Caspase 8 activation was suppressed by clinically relevant levels of narsoplimab. In conclusion, we found that the LP of complement is activated in TMAs of diverse etiology and LP inhibition may be of therapeutic benefit in these disorders., Summary Involvement of the alternative complement pathway (AP) in microvascular endothelial cell (MVEC) injury characteristic of a thrombotic microangiopathy (TMA) is well documented. However, the role of the lectin pathway (LP) of complement has not been explored. We examined mannose‐binding lectin associated serine protease (MASP2), the effector enzyme of the LP, in thrombotic thrombocytopenic purpura, atypical hemolytic uremic syndrome and post‐allogeneic hematopoietic stem cell transplantation (alloHSCT) TMAs. Plasma MASP2 and terminal complement component sC5b‐9 levels were assessed by enzyme‐linked immunosorbent assay (ELISA). Human MVEC were exposed to patient plasmas, and the effect of the anti‐MASP2 human monoclonal antibody narsoplimab on plasma‐induced MVEC activation was assessed by caspase 8 activity. MASP2 levels were highly elevated in all TMA patients versus controls. The relatively lower MASP2 levels in alloHSCT patients with TMAs compared to levels in alloHSCT patients who did not develop a TMA, and a significant decrease in variance of MASP2 levels in the former, may reflect MASP2 consumption at sites of disease activity. Plasmas from 14 of the 22 TMA patients tested (64%) induced significant MVEC caspase 8 activation. This was suppressed by clinically relevant levels of narsoplimab (1·2 μg/ml) for all 14 patients, with a mean 65·7% inhibition (36.8–99.4%; P

Background Hemolytic uremic syndrome (HUS), a common subtype of thrombotic microangiopathy (TMA), is characterized by microangiopathic hemolytic anemia, thrombocytopenia, and acute kidney injury. Shiga toxin-producing Escherichia coli infection is the most common cause of post-diarrheal HUS. Kidney and central nervous system are the primary target organs. Case presentation A 64-year-old male presented with HUS following bloody diarrhea. Nephrotic-range proteinuria and hypoalbuminemia were present at the acute stage and renal histology revealed common TMA features. Neurological involvement presented as confusion and impaired cognitive function. Cranial magnetic resonance imaging demonstrated bilateral T2 hyperintensities in the brainstem and insula. The patient received plasma exchange and supportive care. Both the renal and neurological impairments were completely recovered 3 months after the onset. Conclusion We report an adult patient presenting with nephrotic-range proteinuria and central nervous system involvement at the acute phase of post-diarrheal HUS. The reversibility of the organ damages might predict a favorable outcome.

This article presents two clinical cases of patients with a homozygous deletion of segment of chromosome 1, which covers regions of genes associated with complement factor H, in particular CFHR3. Patients underwent in-depth clinical studies, heredity assessment, laboratory, instrumental and genetic diagnostics. The first clinical case describes a clinical case with deleted chromosome 1 segment in a 9-year-old girl who was diagnosed with atypical hemolytic-uremic syndrome. This is a complement-dependent disease that affects both adults and children. It is known that a defect in any proteins included in the alternative complement activation pathway can lead to atypical hemolytic-uremic syndrome. However, this syndrome is most often caused by defects in chromosome 1 region, including gene sequences associated with complement factor H – CFHR1 and CFHR3. Modern treatment of atypical hemolytic uremic syndrome involves targeted pathogenetic treatment, therefore, the genetic diagnosis seems to be a necessary step for differential diagnosis and confirmation. The patient had fairly typical clinical symptoms, including signs of thrombotic microangiopathy, thrombocytopenia, hemolytic anemia and increasing renal failure. It is also known that her mother had congenital hydronephrosis, and the pregnancy proceeded against a background of ureaplasma, mycoplasma, cytomegalovirus infection, chronic pyelonephritis, and preeclampsia.The second clinical case of a deleted chromosome 1 region, involving the CFHR3 gene, is a description of the disease in a boy of 8 years old, while the disease manifested with alopecia at the age of 4. Intermittent alopecia was the main symptom, while there were no signs of renal failure, thrombocytopenic purpura, and other symptoms characteristic of atypical hemolytic-uremic syndrome. The boy also revealed some congenital defects of the urinary system: bladder diverticulum, unilateral ureterohydronephrosis, and bilateral dilatation of the pyelocaliceal system. The detected genetic defect is usually associated with atypical hemolytic uremic syndrome. However, the phenotype, i.e., clinical manifestations, determined a completely different diagnosis – primary immunodeficiency, a group of complement defects, and a deficiency of complement factor H-related protein. After analyzing the given clinical cases, we can conclude that clinical manifestations may vary significantly in carriers of same gene mutations. This suggests that there are additional factors (genetic or environmental) that can influence the formation of various phenotypic manifestations of this pathology.

Introduction. Hemolytic uremic syndrome (HUS) is a hemorrhagic systemic microangiopathy, which primarily affects the kidney and is defined by the triad: acute renal failure, microangiopathic hemolytic anemia, and thrombocytopenia. We report two cases of HUS with neurological manifestations and different evolution. Cases presentation. We report the cases of two young children, without significant medical history, who were diagnosed with acute renal failure, hemolytic anemia and thrombocytopenia. The onset of the disease was a few days prior to admission, with fever and diarrhea, for which they received symptomatic treatment at home, with worsening of the general condition. The particularity of these cases is that even if the patients had the featured triad of HUS and they were both diagnosed with this disease, the neurological complications evolved differently, with a finally favorable outcome. Conclusions. Hemolytic uremic syndrome (HUS) is described as a multisystemic disease that affects mainly the kidney and is a major cause of morbidity and mortality in children less than 5 years old. The kidney and the brain are the main target organs in patients with HUS. In these two cases, the patients diagnosed with HUS and neurological complications, presented a favorable outcome with specific treatment.

A 62-year-old male who was receiving prednisolone and methotrexate for scleroderma and rheumatoid arthritis complained of diarrhea and vomiting, and was transferred to our hospital for detailed examination and treatment of renal dysfunction and thrombocytopenia. Hemolytic anemia and crushed erythrocytes were found during the patient’s course; therefore, we suspected thrombotic microangiopathy (TMA). His ADAMTS13 activity was 60.3% and his ADAMTS13 inhibitor was under 0.5. In addition, his blood culture was positive for Streptococcus pneumoniae, and we finally diagnosed Streptococcus pneumoniae-associated TMA (pTMA). The patient was treated with antibiotics and hemodialysis. The patient recovered and was discharged on the 45th hospital day. Adult pTMA cases are remarkably rare. We herein report a successfully treated adult case of pTMA.

Hemolytic uremic syndrome (HUS) may result in thrombotic central nervous system complications. We present a child with diarrhea‐associated HUS who developed new‐onset focal seizures secondary to cerebral sinovenous thrombosis (CSVT). Her CSVT was treated with low‐molecular‐weight heparin. The patient’s seizures were controlled with levetiracetam, and her HUS was managed supportively with hemodialysis. Repeat imaging nearly 6 months following presentation and initiation of anticoagulation demonstrated cerebral sinus enlargement and persistent intraluminal webbing. Anticoagulation was discontinued after 6 months, and she did not experience long‐term gross neurologic sequelae. CSVT is a complication of HUS that has not been previously described. In this report, we summarize the thrombotic central nervous system complications of pediatric HUS.

Background. Acute intestinal infections (AII) caused by Shiga-like toxin-producing Escherichia coli and accompanied by hemolytic uremic syndrome (HUS) development are characterized by rapid progression and poor prognosis. Bloody diarrhea (hemorrhagic colitis) requires timely medical treatment both at young age and at adolescence. The severe course of HUS affected by AII caused by enterohaemorrhagic Escherichia coli requires additional medical attention and timely renal replacement therapy (hemodialysis). Clinical Case Description. The description and analysis of the severe course of HUS affected by AII in 14 years old adolescent girl is presented. There were some difficulties during diagnostics and thus the pathogenetic therapy onset was delayed. Differential diagnosis between typical and atypical HUS was performed. The disease was characterized by rapid progression of acute kidney injury, cerebrovascular disease and ischemia, multiple organ dysfunction syndrome and disseminated intravascular coagulation resulting in fatal case. Conclusion. Atypical HUS is the most frequent cause of multiple organ dysfunction syndrome alongside with acute kidney injury. The challenges of early diagnostics of atypical GUS in childhood are not fully solved nowadays and require additional attention of pediatricians. The clinical case of atypical GUS complicated by intestinal infection caused by enterohaemorrhagic Escherichia coli is described in this article. The severity of the disease course was due to the early manifestation of extrarenal symptoms and multiple organ failure.

Shiga toxin (Stx)-producing Escherichia coli (STEC) can cause a wide range of symptoms from asymptomatic carriage, mild diarrhea to bloody diarrhea (BD) and hemolytic uremic syndrome (HUS). Intimin, encoded by the eae gene, also plays a critical role in STEC pathogenesis. Herein, we investigated the prevalence and genetic diversity of eae among clinical STEC isolates from patients with diarrhea, BD, HUS as well as from asymptomatic STEC-positive individuals in Sweden with whole-genome sequencing. We found that 173 out of 239 (72.4%) of clinical STEC strains were eae positive. Six eae subtypes (epsilon 1, gamma 1, beta 3, theta, zeta and rho) were identified eae and its subtype gamma 1 were significantly overrepresented in O157:H7 strains isolated from BD and HUS patients. epsilon 1 was associated with O121:H19 and O103:H2 strains, and beta 3 to O26:H11 strains. The combination of eae subtype gamma 1 and stx subtype (stx (2) or stx (1)+stx (2)) is more likely to cause severe disease, suggesting the possibility of using eae genotypes in risk assessment of STEC infection. In summary, this study demonstrated a high prevalence of eae in clinical STEC strains and considerable genetic diversity of eae in STEC strains in Sweden from 1994 through 2018, and revealed association between eae subtypes and disease severity. Funding Agencies|Scandinavian Society for Antimicrobial Chemotherapy Foundation [SLS884041]; National Natural Science Foundation of ChinaNational Natural Science Foundation of China (NSFC) [81701977]; Natural Science Foundations of Guangdong ProvinceNational Natural Science Foundation of Guangdong Province [2018B030311063, 2019A1515111004]

Shiga toxin-producing Escherichia coli O157:H7 is a virulent strain causing severe gastrointestinal infection, hemolytic uremic syndrome and death. To date there are no specific therapies to reduce progression of disease. Here we investigated the effect of pooled immunoglobulins (IgG) on the course of disease in a mouse model of intragastric E. coli O157:H7 inoculation. Intraperitoneal administration of murine IgG on day 3, or both on day 3 and 6, post-inoculation improved survival and decreased intestinal and renal pathology. When given on both day 3 and 6 post-inoculation IgG treatment also improved kidney function in infected mice. Murine and human commercially available IgG preparations bound to proteins in culture filtrates from E. coli O157:H7. Bound proteins were extracted from membranes and peptide sequences were identified by mass spectrometry. The findings showed that murine and human IgG bound to E. coli extracellular serine protease P (EspP) in the culture filtrate, via the IgG Fc domain. These results were confirmed using purified recombinant EspP and comparing culture filtrates from the wild-type E. coli O157:H7 strain to a deletion mutant lacking espP. Culture filtrates from wild-type E. coli O157:H7 exhibited enzymatic activity, specifically associated with the presence of EspP and demonstrated as pepsin cleavage, which was reduced in the presence of murine and human IgG. EspP is a virulence factor previously shown to promote colonic cell injury and the uptake of Shiga toxin by intestinal cells. The results presented here suggest that IgG binds to EspP, blocks its enzymatic activity, and protects the host from E. coli O157:H7 infection, even when given post-inoculation.

Shiga toxins (Stxs) produced by enterohemorrhagic Escherichia coli (EHEC) are the major virulence factors responsible for hemorrhagic colitis, which can lead to life‐threatening systemic complications including acute renal failure (hemolytic uremic syndrome) and neuropathy. Here, we report that O‐GlcNAcylation, a type of post‐translational modification, was acutely increased upon induction of endoplasmic reticulum (ER) stress in host cells by Stxs. Suppression of the abnormal Stx‐mediated increase in O‐GlcNAcylation effectively inhibited apoptotic and inflammatory responses in Stx‐susceptible cells. The protective effect of O‐GlcNAc inhibition for Stx‐mediated pathogenic responses was also verified using three‐dimensional (3D)‐cultured spheroids or organoids mimicking the human kidney. Treatment with an O‐GlcNAcylation inhibitor remarkably improved the major disease symptoms and survival rate for mice intraperitoneally injected with a lethal dose of Stx. In conclusion, this study elucidates O‐GlcNAcylation‐dependent pathogenic mechanisms of Stxs and demonstrates that inhibition of aberrant O‐GlcNAcylation is a potential approach to treat Stx‐mediated diseases.

Hemolytic uremic syndrome (HUS), the leading cause of acute renal failure in children (< 3 years), is mainly related to Shiga toxins (Stx)-producing Escherichia coli (STEC) infections. STEC are confined to the gut resulting in hemorrhagic colitis, whereas Stx are delivered in blood to target kidney and brain, with unclear mechanisms, triggering HUS in 5 to 15% of infected children. Stx were found on circulating cells, free in sera (soluble Stx) or in blood cell-derived microvesicles (particulate Stx), whereby the relationship between these forms of circulating toxins is unclear. Here, we have examined 2,846 children with bloody diarrhea and found evidence of STEC infection in 5%. Twenty patients were enrolled to study the natural course of STEC infections before the onset of HUS. In patients, Stx were found to be associated to circulating cells and/or free and functionally active in sera. In most children, Stx were bound to neutrophils when high amounts of toxins were found in feces. Time-course analysis showed that Stx increased transiently in patients' sera while the decrease of toxin amount on leukocytes was observed. Notably, patients who recovered (85%) displayed different settings than those who developed HUS (15%). The distinctive feature of the latter group was the presence in blood of particulate Stx2 (Stx2 sedimented at g-forces corresponding to 1 μm microvesicles) the day before diagnosis of HUS, during the release phase of toxins from circulating cells. This observation strongly suggests the involvement of blood cell-derived particulate Stx2 in the transition from hemorrhagic colitis to HUS.

Thrombotic microangiopathies (TMA) are a group of disorders characterized by generalized microvascular occlusion, thrombocytopenia, and microangiopathic hemolytic anemia, which may present with organ dysfunction. These include hemolytic uremic syndrome (HUS) and thrombotic thrombocytopenic purpura (TTP) among others. The triad of anemia, thrombocytopenia, and acute kidney injury is the hallmark of HUS. It can be associated with Shiga toxin-producing Escherichia coli infection, complement-mediated (atypical HUS), coagulation or metabolism-mediated (predominantly in children of less than one year of age), or secondary HUS with the coexisting disease. HUS is a potentially fatal condition irrespective of its cause, and hence the diagnosis and management approach must be swift. The treatment is support-based; however, in severe cases, the use of plasmapheresis has shown favorable outcomes. In this report, we discuss a case of a 30-year-old male who presented with acalculous acute pancreatitis with HUS, a rare case of secondary HUS previously reported in a few case reports.

Shiga toxins (Stxs) produced by enterohemorrhagic Escherichia coli (EHEC) are the major virulence factors responsible for hemorrhagic colitis, which can lead to life‐threatening systemic complications including acute renal failure (hemolytic uremic syndrome) and neuropathy. Here, we report that O‐GlcNAcylation, a type of post‐translational modification, was acutely increased upon induction of endoplasmic reticulum (ER) stress in host cells by Stxs. Suppression of the abnormal Stx‐mediated increase in O‐GlcNAcylation effectively inhibited apoptotic and inflammatory responses in Stx‐susceptible cells. The protective effect of O‐GlcNAc inhibition for Stx‐mediated pathogenic responses was also verified using three‐dimensional (3D)‐cultured spheroids or organoids mimicking the human kidney. Treatment with an O‐GlcNAcylation inhibitor remarkably improved the major disease symptoms and survival rate for mice intraperitoneally injected with a lethal dose of Stx. In conclusion, this study elucidates O‐GlcNAcylation‐dependent pathogenic mechanisms of Stxs and demonstrates that inhibition of aberrant O‐GlcNAcylation is a potential approach to treat Stx‐mediated diseases., Here we identify a previously unknown link between the O‐GlcNAcylation pathway and the pathogenesis of enterohemorrhagic E. coli Shiga toxin‐mediated diseases. Given the capacity of these bacterial toxins to subvert normal cellular regulation in the host, this study demonstrates that Shiga toxins alter O‐GlcNAcylation, a type of post‐translational modification, to exacerbate dysfunction in host cell signaling.

Shiga toxin (Stx)-producing Escherichia coli (STEC) infection is the most common cause of hemolytic uremic syndrome (HUS), one of the main causes of acute kidney injury in children. Stx plays an important role in endothelium damage and pathogenesis of STEC-HUS. However, the effects of Stx on neutrophils and neutrophil extracellular trap (NET) formation are not well understood. In this study, we investigated how Stx2a affects NET formation and NETotic pathways (NADPH or NOX-dependent and -independent) using neutrophils isolated from healthy donors and patients with STEC-HUS, during the acute and recovery phase of the disease. Stx2a dose-dependently induced NETosis in neutrophils isolated from both healthy controls and STEC-HUS patients. NETosis kinetics and mechanistic data with pathway-specific inhibitors including diphenyleneiodonium (DPI)-, ERK-, and P38-inhibitors showed that Stx2a-induced NETosis via the NOX-dependent pathway. Neutrophils from STEC-HUS patients in the acute phase showed less ROS and NETs formation compared to neutrophils of the recovery phase of the disease and in healthy controls. NETs induced by Stx2a may lead to the activation of endothelial cells, which might contribute to the manifestation of thrombotic microangiopathy in STEC-HUS. ispartof: BIOMEDICINES vol:9 issue:12 ispartof: location:Switzerland status: published

Background Cardiac and neurological involvement in hemolytic uremic syndrome are life-threatening complications. The most frequent complications of cardiac involvement in hemolytic uremic syndrome are myocarditis and cardiac dysfunction due to fluid overload. Pericarditis remains very rare in hemolytic uremic syndrome. To our knowledge, only five cases of cardiac tamponade associated with hemolytic uremic syndrome have been described in literature. Case summary A 27-month-old Caucasian girl presented with symptoms of nonbloody diarrhea and tonic-clonic seizures. The diagnosis of Shiga-like toxin-producing Escherichia coli hemolytic uremic syndrome with central nervous system involvement was made, and stool examination revealed infection with a Shiga-like toxin-producing Escherichia coli. She did not need renal replacement therapy but had severe neurological impairment. The patient’s course was complicated by pericardial effusion. A pericardiocentesis was performed via an apical approach because the pericardial effusion was predominantly surrounding the left ventricle. Effusion analysis showed an exudate and positivity for human herpesvirus-6B on polymerase chain reaction with viremia. This finding was consistent with primary human herpesvirus-6 infection with encephalitis. Conclusion We report this uncommon case of Shiga-like toxin-producing Escherichia coli hemolytic uremic syndrome associated with a severe human herpesvirus-6 infection. Secondary isolated pericardial effusion and atypical neurological involvement are uncommon in Shiga-like toxin-producing Escherichia coli hemolytic uremic syndrome and should lead the physician to perform additional investigations.

The complex pathophysiologic interplay between SARS-CoV-2 infection and complement activation is the subject of active investigation. It is clinically mirrored by the occurrence of exacerbations of complement mediated diseases during COVID-19 infection. These include complement-mediated hemolytic anemias such as paroxysmal nocturnal hemoglobinuria (PNH), autoimmune hemolytic anemia (AIHA), particularly cold agglutinin disease (CAD), and hemolytic uremic syndrome (HUS). All these conditions may benefit from complement inhibitors that are also under study for COVID-19 disease. Hemolytic exacerbations in these conditions may occur upon several triggers including infections and vaccines and may require transfusions, treatment with complement inhibitors and/or immunosuppressors (i.e., steroids and rituximab for AIHA), and result in thrombotic complications. In this manuscript we describe four patients (2 with PNH and 2 with CAD) who experienced hemolytic flares after either COVID-19 infection or SARS-Cov2 vaccine and provide a review of the most recent literature. We report that most episodes occurred within the first 10 days after COVID-19 infection/vaccination and suggest laboratory monitoring (Hb and LDH levels) in that period. Moreover, in our experience and in the literature, hemolytic exacerbations occurring during COVID-19 infection were more severe, required greater therapeutic intervention, and carried more complications including fatalities, as compared to those developing after SARS-CoV-2 vaccine, suggesting the importance of vaccinating this patient population. Patient education remains pivotal to promptly recognize signs/symptoms of hemolytic flares and to refer to medical attention. Treatment choice should be based on the severity of the hemolytic exacerbation as well as of that of COVID-19 infection. Therapies include transfusions, complement inhibitor initiation/additional dose in the case of PNH, steroids/rituximab in patients with CAD and warm type AIHA, plasma exchange, hemodialysis and complement inhibitor in the case of atypical HUS. Finally, anti-thrombotic prophylaxis should be always considered in these settings, provided safe platelet counts.

The objective of this study was to determine sources of Shiga toxin-producing Escherichia coli O157 (STEC O157) infection among visitors to Farm X and develop public health recommendations. A case-control study was conducted. Case-patients were defined as the first ill child (aged ; of these, 62% (18 of 29) yielded STEC O157 highly related by WGS to patient isolates. STEC O157 environmental contamination and fecal shedding by goats at Farm X was extensive. Farms should provide handwashing stations with soap, running water, and disposable towels. Access to animal areas, including animal pens and enclosures, should be limited for young children who are at risk for severe outcomes from STEC O157 infection. National recommendations should be adopted to reduce disease transmission.

The hemolytic uremic syndrome associated with diarrhea, a consequence of Shiga toxin (Stx)-producing Escherichia coli infection, is a common cause of pediatric acute renal failure in Argentina. Stx type 2a (Stx2a) causes direct damage to renal cells and induces local inflammatory responses that involve secretion of inflammatory mediators and the recruitment of innate immune cells. γδ T cells constitute a subset of T lymphocytes, which act as early sensors of cellular stress and infection. They can exert cytotoxicity against infected and transformed cells, and produce cytokines and chemokines. In this study, we investigated the activation of human peripheral γδ T cells in response to the incubation with Stx2a-stimulated human glomerular endothelial cells (HGEC) or their conditioned medium, by analyzing in γδ T lymphocytes, the expression of CD69, CD107a, and perforin, and the production of TNF-α and IFN-γ. In addition, we evaluated by confocal microscopy the contact between γδ T cells and HGEC. This analysis showed an augmentation in cellular interactions in the presence of Stx2a-stimulated HGEC compared to untreated HGEC. Furthermore, we observed an increase in cytokine production and CD107a expression, together with a decrease in intracellular perforin when γδ T cells were incubated with Stx2a-treated HGEC or their conditioned medium. Interestingly, the blocking of TNF-α by Etanercept reversed the changes in the parameters measured in γδ T cells incubated with Stx2a-treated HGEC supernatants. Altogether, our results suggest that soluble factors released by Stx2a-stimulated HGEC modulate the activation of γδ T cells, being TNF-α a key player during this process.

The complement pathway is an essential mechanism in innate immunity, but it is also involved in multiple pathologies. For kidney diseases, strong evidence of a dysregulation in the alternative pathway in atypical hemolytic uremic syndrome (aHUS) led to the use of eculizumab, the first anti-C5 inhibitor available in clinical practice. Intensive fundamental research resulted in the development of subsequent new drugs, such as long-acting C5 inhibitors, oral medications, or antagonists of C5aR, the receptor for C5a. New data in the domain of C5-inhibition in glomerular diseases are still limited and mainly focus on 1) the efficacy of ravulizumab, a long-acting C5 inhibitor in aHUS, and 2) the use of avacopan, a C5aR antagonist, in antineutrophil cytoplasmic antibody vasculitis. Several new studies ongoing or planned for the next few years will evaluate the efficacy of C5 inhibition in secondary thrombotic microangiopathy, C3 glomerulopathy, membranous nephropathy, or immunoglobulin A nephropathy.

In this case report, we report a pediatric patient with COVID-19 and atypical hemolytic uremic syndrome (aHUS). A 3-year-old girl with fever and respiratory distress was admitted to the hospital. The patient tested positive for COVID-19 by a PCR test. As her respiratory distress increased and blood gas indicated deep respiratory acidosis on the third day of the pediatric intensive care unit follow-up, the patient was intubated and ventilated. Thorax computerized tomography (CT) showed bilateral effusion and atelectasis. During her follow-up, the pleural effusion resolved but there were marked consolidation areas and ground glass opacities compatible with COVID-19 on the follow-up CT. On the 10th day, she became anuric and developed progressive thrombocytopenia and persistent microangiopathic hemolytic anemia, which were suggestive of HUS given a high creatinine level (1.9 mg/dl), an undetectable haptoglobin level, reticulocytosis (8%), and an LDH level of 2540 U/l. Direct Coombs test returned negative. Examination of a peripheral blood smear revealed schistocytes. Disseminated intravascular coagulation was ruled out by normal INR and PTT. In the light of the available findings, we considered the patient to have thrombotic microangiopathy (TMA) triggered by COVID-19. It was not a TTP-form of TMA but rather an aHUS type, based on an ADAMTS13 activity level >5%. Hence, plasmapheresis was performed with fresh frozen plasma (FFP). After 4 weeks, she became completely asymptomatic, and her hemodynamic parameters normalized. COVID-19 induced uncontrolled complement activation leading to the development of aHUS. Early diagnosis and treatment may reduce morbidity and mortality since its treatment options.

Shiga toxin-encoding genes (stx) of enterohemorrhagic Escherichia coli (EHEC) can be lost during infection or in vitro cultivation, and in clinical practice, it is difficult to distinguish EHEC that have lost stx (EHEC-LST) from enteropathogenic E. coli (EPEC), as both are stx-negative and eae-positive. In this study, we performed whole-genome sequencing (WGS) of a stx-negative, eae-positive E. coli O63:H6 isolate from a child with hemolytic uremic syndrome and compared its genome with those of nine E. coli O63:H6 strains in public databases. Virulence gene profiles were analyzed and core-genome multilocus sequence typing (cgMLST) was conducted. The virulence gene profile of our isolate was consistent with EHEC, except for the absence of stx, and the isolate clustered with seven EHEC strains but was distant from two EPEC strains in cgMLST. In genome alignment, our isolate exhibited a high nucleotide identity with EHEC strain 377323_2f but displayed a gap corresponding to the stx-harboring prophage sequence. Overall, our isolate was genetically closely related to EHEC strains, consistent with this being an EHEC-LST strain. As EHEC-LST may be misdiagnosed as EPEC in routine laboratories, comparative genomic analysis using WGS can be useful to determine whether stx-negative and eae-positive isolates are EHEC-LST or EPEC.

BACKGROUND AND OBJECTIVES: In contrast to shigatoxin-associated Escherichia coli (STEC) causing hemolytic uremic syndrome, STEC-unrelated infections associated with thrombotic microangiopathy are less characterized. DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS: Our retrospective study in a four-hospital institution of 530 consecutive patients with adjudicated thrombotic microangiopathies during the 2009–2016 period studied STEC-unrelated infections’ epidemiology and major outcomes (death, acute dialysis, and major cardiovascular events). RESULTS: STEC-unrelated infection was present in 145 of 530 (27%) patients, thrombotic microangiopathies without infection were present in 350 of 530 (66%) patients, and STEC causing hemolytic and uremic syndrome was present in 35 of 530 (7%) patients. They (versus thrombotic microangiopathy without infection) were associated with age >60 years (36% versus 18%), men (53% versus 27%), altered consciousness (32% versus 11%), mean BP

Treatment of Shiga toxin-producing Escherichia coli O157 (O157) diarrhea with antimicrobials might alter the risk of hemolytic uremic syndrome (HUS). However, full characterization of which antimicrobials might affect risk is lacking, particularly among adults. To inform clinical management, we conducted a case-control study of residents of the FoodNet surveillance areas with O157 diarrhea during a 4-year period to assess antimicrobial class-specific associations with HUS among persons with O157 diarrhea. We collected data from medical records and patient interviews. We measured associations between treatment with agents in specific antimicrobial classes during the first week of diarrhea and development of HUS, adjusting for age and illness severity. We enrolled 1308 patients, 102 (7.8%) developed confirmed HUS. Antimicrobial treatment varied by age: &lt, 5 years (12.6%), 5–14 (11.5%), 15–39 (45.4%), ≥40 (53.4%). Persons treated with a β-lactam had higher odds of developing HUS (OR 2.80, CI 1.14–6.89). None of the few persons treated with a macrolide developed HUS, but the protective association was not statistically significant. Exposure to “any antimicrobial” was not associated with increased odds of HUS. Our findings confirm the risk of β-lactams among children with O157 diarrhea and extends it to adults. We observed a high frequency of inappropriate antimicrobial treatment among adults. Our data suggest that antimicrobial classes differ in the magnitude of risk for persons with O157 diarrhea.

Background: We aimed to determine the prevalence of hypoalbuminemia in STEC-HUS patients with hemorrhagic colitis (HC) and whether serum albumin level (SAL), leukocyte count, hematocrit and serum sodium level (SSL) are prognostic markers of HC, central nervous system disease (CNSd) and/or dialysis requirement and evaluate if hypoalbuminemia is associated with fecal protein losses. Methods: We prospectively evaluated STEC-HUS patients treated at our institution from 9/2011 to 2/2019, analyzing the presence of HC, CNSd and dialysis requirement and SAL, SSL, leukocytes, hematocrit and α1-antitrypsin clearance. Results: We evaluated 98 patients, with mean age of 33.3 months. SAL ≤ 29.5 g/l, > 24,600 leukocytes/mm³ and hematocrit > 30% behave as independent prognostic markers for HC. SAL ≤ 28 g/l, > 25,200 leukocytes/mm³ and hematocrit > 30% behave as prognostic markers for CNSd. SAL ≤ 31.6 g/l, > 13,800 leukocytes/mm³, hematocrit > 18.9% and hyponatremia (≤ 132 mEq/l) behave as prognostic markers for dialysis requirement. However, in multivariate logistic regression models, only hypoalbuminemia behaved as a risk factor for HC, CNSd and dialysis. α1-antitrypsin clearance was performed in 69 patients and was high in 9/69 (13%), only 4 with HC. No significant association was observed between α1-antitrypsin clearance and albuminemia (χ² = 0.1076, p = 0.7429) as well as α1-antitrypsin clearance and HC (χ² = 1.7892, p = 0.1810). Conclusions: Almost all patients with HC had hypoalbuminemia, which behaves as a risk factor for HC, CNSd and dialysis requirement. No significant association was observed between elevated α1-antitrypsin clearance and hypoalbuminemia nor between elevated α1-antitrypsin clearance and HC. These findings could be related to the small number of evaluated patients., Facultad de Ciencias Médicas, Facultad de Ciencias Veterinarias

Diarrhea-associated hemolytic uremic syndrome (HUS) occurs sporadically in the community. It is well known in the pediatric age group but also occurs in the adults, albeit with lower frequency. Prompt recognition of diarrhea-associated HUS is important, as it can be easily overlooked, as prerenal acute kidney injury. Besides this, management of diarrhea-associated HUS is different; varying from supportive care with meticulous observation for spontaneous recovery to occur, or to institute specific therapy such as plasmapheresis or immunosuppressant drugs, if it evolves into organ or life-threatening thrombotic microangiopathy (TMA). HUS is one type of TMA. Steroids have been used anecdotally either standalone or in combination with other therapies, in the management of TMA, especially if it is immune-mediated TMA. In our two cases of diarrhea associated TMA/HUS, we used steroids successfully as an empiric therapy for life threatening TMA.