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Background Candidatus (Ca.) Neoehrlichia (N.) mikurensis is an emerging tick-borne pathogen of humans that is closely related to Ehrlichia and Anaplasma species. This strict intracellular bacterium escapes detection by routine microbiologic diagnostic methods such as blood culture, leading to considerable under-diagnosis of the infectious disease it causes, neoehrlichiosis. Methods Here, we describe the vascular and thromboembolic events afflicting a series of 40 patients diagnosed with neoehrlichiosis in Sweden during a 10-year period (2009–2019). Results The majority of the patients (60%) developed vascular events ranging from repeated thrombophlebitis, deep vein thrombosis, pulmonary embolism, transitory ischemic attacks, to arteritis. Younger age was a risk factor for vascular complications. In contrast, there was no difference in the incidence of vascular events between immunosuppressed and immunocompetent patients. However, there were qualitative differences, such that deep vein thrombosis exclusively afflicted the immunosuppressed patients, whereas arteritis was restricted to the immunocompetent persons. We also present the case histories of two patients who developed vasculitis mimicking polyarteritis nodosa and giant cell arteritis. Both were cured by doxycycline treatment. Conclusions Ca. N. mikurensis infection should be considered in patients living in tick-endemic areas of Europe and northern Asia who present with atypical vascular and/or thromboembolic events. Early diagnosis and antibiotics targeting this emerging infectious agent can eradicate the infection and prevent the development of new vascular events.

Background The knowledge regarding the occurrence and the clinical implications of tick-borne infections in immunosuppressed patients living in tick-endemic areas is limited. Methods Adult patients with autoimmune conditions requiring immunosuppressive treatment such as infliximab and rituximab were invited to participate in the study when they attended the hospital for treatment and/or control of the disease. Whole-blood samples were analyzed by real-time polymerase chain reaction for Borrelia burgdorferi sensu lato, Borrelia miyamotoi, Anaplasma phagocytophilum, Rickettsia spp., Candidatus Neoehrlichia mikurensis, and Babesia spp. Results The occurrence of tick-borne pathogens in the blood of patients (n = 163) with autoimmune conditions requiring immunosuppressive treatment was evaluated. Pathogen DNA was detected in 8.6% (14/163) of the patients. The predominant pathogen was Ca. Neoehrlichia mikurensis (12/14), which was carried in the blood of infected patients for 10–59 days until treatment with doxycycline. B. burgdorferi s.l. and Rickettsia spp. were detected in 1 patient each. The B. burgdorferi–infected patient presented with fever, whereas the remaining patients were judged to have subclinical infections. B. miyamotoi, A. phagocytophilum, and Babesia spp. were not detected in any patient. Conclusions Patients treated with biologicals and living in a tick-endemic area seem to have a high risk of contracting Ca. Neoehrlichia mikurensis infection, which, if left untreated, could result in thromboembolic complications.

Noninvasive methods to assess treatment response in eosinophilic esophagitis are needed. Our aim was to determine whether a blood-based biomarker panel centered on immune parameters could identify histologic response to treatment in eosinophilic esophagitis patients. A pilot study involving adult patients with active eosinophilic esophagitis recruited at two Ear, Nose, Throat clinics in Sweden was designed. The patients (n = 20) donated blood and esophageal biopsies and filled in three questionnaires before and after a 2-month course of topical corticosteroids. Blood samples were analyzed for absolute levels of granulocytes and T cells and the fractions of eosinophils expressing 10 different surface markers by flow cytometry. All data were analyzed by multivariate methods of pattern recognition. Multivariate modeling revealed that a combination of 13 immune parameters and 10 patient-reported outcome scores were required to create a model capable of separating responders (n = 15) from non-responders (n = 5). Questions regarding symptoms of esophageal dysfunction and capacity to eat certain foods from two of the questionnaires were discriminatory in the multivariate model, as were absolute counts of T cells, eosinophils, and eosinophil expression of activation markers and cell adhesion molecules. A combination of blood-based immune parameters and directed questions may prove helpful to monitor response to treatment, perhaps reducing the need for repeat endoscopies in eosinophilic esophagitis patients in the future.

Syphilis is an important sexually transmitted infection caused by the bacterium Treponema pallidum subspecies pallidum. The last two decades have seen syphilis incidence rise in many high-income countries, yet the evolutionary and epidemiological relationships that underpin this are poorly understood, as is the global T. pallidum population structure. We assembled a geographically and temporally diverse collection of clinical and laboratory samples comprising 726 T. pallidum genomes. We used detailed phylogenetic analysis and clustering to show that syphilis globally can be described by only two deeply branching lineages, Nichols and SS14. We show that both of these lineages can be found circulating concurrently in 12 of the 23 countries sampled. To provide further phylodynamic resolution we subdivided Treponema pallidum subspecies pallidum into 17 distinct sublineages. Importantly, like SS14, we provide evidence that two Nichols sublineages have expanded clonally across 9 countries contemporaneously with SS14. Moreover, pairwise genome analysis showed that recent isolates circulating in 14 different countries were genetically identical in their core genome to those from other countries, suggesting frequent exchange through international transmission pathways. This contrasts with the majority of samples collected prior to 1983, which are phylogenetically distinct from these more recently isolated sublineages. Bayesian temporal analysis provided evidence of a population bottleneck and decline occurring during the late 1990s, followed by a rapid population expansion a decade later. This was driven by the dominant T. pallidum sublineages circulating today, many of which are resistant to macrolides. Combined we show that the population of contemporary syphilis in high-income countries has undergone a recent and rapid global expansion.

Increased number of eosinophils in the uterus has been reported under physiological and pathologic conditions. However, eosinophilic infiltration limited to the myometrium is very unusual. A rare finding of isolated eosinophilic infiltration in the myometrium without involvement of endometrium or pathologies in the cervix or ovaries was observed in a 31-yr-old woman seeking medical attention for unexplained infertility, abnormal uterine bleeding, and dysmenorrhea. The patient had no allergies, parasitic disease, or other systemic disorders. This rare manifestation of eosinophilic infiltration expands the differential diagnosis of inflammatory conditions of the myometrium in patients with gynecological issues.

Syphilis is an important sexually transmitted infection caused by the bacterium Treponema pallidum subspecies pallidum. The last two decades have seen syphilis incidence rise in many high-income countries, yet the evolutionary and epidemiological relationships that underpin this are poorly understood, as is the global T. pallidum population structure. We assembled a geographically and temporally diverse collection of clinical and laboratory samples comprising 726 T. pallidum genomes. We used detailed phylogenetic analysis and clustering to show that syphilis globally can be described by only two deeply branching lineages, Nichols and SS14. We show that both of these lineages can be found circulating concurrently in 12 of the 23 countries sampled. To provide further phylodynamic resolution we subdivided Treponema pallidum subspecies pallidum into 17 distinct sublineages. Importantly, like SS14, we provide evidence that two Nichols sublineages have expanded clonally across 9 countries contemporaneously with SS14. Moreover, pairwise genome analysis showed that recent isolates circulating in 14 different countries were genetically identical in their core genome to those from other countries, suggesting frequent exchange through international transmission pathways. This contrasts with the majority of samples collected prior to 1983, which are phylogenetically distinct from these more recently isolated sublineages. Bayesian temporal analysis provided evidence of a population bottleneck and decline occurring during the late 1990s, followed by a rapid population expansion a decade later. This was driven by the dominant T. pallidum sublineages circulating today, many of which are resistant to macrolides. Combined we show that the population of contemporary syphilis in high-income countries has undergone a recent and rapid global expansion.

Eosinophils differentiate and mature in the thymus, outside of the bone marrow, in healthy individuals. Locally developed thymic eosinophils may contribute to the maturation and selection of human thymocytes.

Neoehrlichia (N.) mikurensis, an intracellular tick-borne bacterium not detected by routine blood culture, is prevalent in ticks in Scandinavia, Central Europe and Northern Asia, and may cause long-standing fever, nightly sweats, migrating pain, skin rashes and thromboembolism, especially in patients treated with rituximab. The multiple symptoms may raise suspicion of both infection, inflammation and malignancy, and lead in most cases to extensive medical investigations across many medical specialist areas and a delay of diagnosis. We describe a complex, albeit typical, case of neoehrlichiosis in a middle-aged splenectomised male patient with a malignant lymphoma, receiving treatment with rituximab. The multifaceted clinical picture associated with this tick-borne disease is addressed, and longitudinal clinical and laboratory data, as well as imaging, are provided. Longstanding relapsing fever in combination with thrombosis in superficial and deep veins in an immunocompromised patient living in a tick-endemic region should raise the suspicion of the emerging tick-borne disease neoehrlichiosis. Given the varied clinical presentation and the risk of delay in diagnosis and treatment, we believe it is important to raise clinicians awareness of this emerging infection, which is successfully treated with doxycycline. Funding Agencies|Region Ostergoetland (ALF grants); Swedish government; Region Vaestra GoetalandRegion Auvergne-Rhone-AlpesRegion Bourgogne-Franche-ComteRegion Hauts-de-FranceRegion Nouvelle-Aquitaine [ALFGBG-722141]; North Sea Programme of the European Regional Development Fund of the European Union (NorthTick); Swedish Research CouncilSwedish Research CouncilEuropean Commission [2020-01287]

The lack of a Swedish patient-reported outcome instrument for eosinophilic esophagitis (EoE) has limited the assessment of the disease. The aims of the study were to translate and validate the Eosinophilic Esophagitis Activity Index (EEsAI) to Swedish and to assess the symptom severity of patients with EoE compared to a nondysphagia control group. The EEsAI was translated and adapted to a Swedish cultural context (S-EEsAI) based on international guidelines. The S-EEsAI was validated using adult Swedish patients with EoE (n = 97) and an age- and sex-matched nondysphagia control group (n = 97). All participants completed the S-EEsAI, the European Organization for Research and Treatment of Cancer Quality of Life Questionnaire-Oesophageal Module 18 (EORTC QLQ-OES18), and supplementary questions regarding feasibility and demographics. Reliability and validity of the S-EEsAI were evaluated by Cronbach’s alpha and Spearman correlation coefficients between the domains of the S-EEsAI and the EORTC QLQ-OES18. A test–retest analysis of 29 patients was evaluated through intraclass correlation coefficients. The S-EEsAI had sufficient reliability with Cronbach’s alpha values of 0.83 and 0.85 for the “visual dysphagia question” and the “avoidance, modification and slow eating score” domains, respectively. The test–retest reliability was sufficient, with good to excellent intraclass correlation coefficients (0.60–0.89). The S-EEsAI domains showed moderate correlation to 6/10 EORTC QLQ-OES18 domains, indicating adequate validity. The patient S-EEsAI results differed significantly from those of the nondysphagia controls (p

INTRODUCTION: Collagenous gastritis (CG), a rare disorder of unknown etiology, has been postulated to have immune-mediated mechanisms. We investigated (i) the incidence and prevalence of CG in a pediatric population; (ii) the clinical, endoscopic, and histologic characteristics of childhood-onset CG; and (iii) the evidence for autoimmunity and/or inflammatory activity in these patients.METHODS: Clinical, endoscopic, and histologic data were reviewed longitudinally in a population-based Swedish cohort of 15 patients with childhood-onset CG diagnosed in the period 2008-2019. A set of 11 autoantibodies, 4 blood inflammatory biomarkers, and the human leukocyte antigen DQ2/DQ8 genotype was analyzed cross-sectionally.RESULTS: The incidence rate of childhood-onset CG was 0.25/100,000 person-years, with an incidence rate ratio of girls to boys of 4.2 (95% confidence interval, 1.2-15). The prevalence of CG was 2.1/100,000 in children aged younger than 18 years. The endoscopic and histologic findings remained pathologic in all the examined patients during a median follow-up of 4.4 years. Many patients had heredity for autoimmune disorders (47%) and/or tested positive for autoantibodies (40%) or human leukocyte antigen DQ2/DQ8 (53%). No associated autoimmune comorbidities were observed. The serum levels of calprotectin and amyloid A were increased in 10/15 (67%) and 5/15 (33%) of the patients, respectively, whereas plasma C-reactive protein levels were normal in all, but 1 patient.DISCUSSION: The results indicate that childhood-onset CG is rare and has a chronic disease course. Although signs of autoimmune predisposition are frequent, early development of autoimmune comorbidities seems seldom. Serum calprotectin and amyloid A represent novel candidate biomarkers of inflammatory activity in CG (see Visual Abstract, Supplementary Digital Content 4, http://links.lww.com/CTG/A349).

Summary Galectin-10 is involved in the T cell suppressive activity of regulatory T cells and eosinophils alike. We have identified a subpopulation of T cell suppressive eosinophils that express CD16 on the surface and contain more galectin-10 compared with conventional CD16-negative eosinophils. Our main goal was to determine how the intracellular protein galectin-10 is released from eosinophils when exposed to proliferating T cells and if such release could be inhibited. Confocal microscopy and imaging flow cytometry were used to study the release of galectin-10 from eosinophils incubated with polyclonally activated T cells. T cell proliferation was monitored by measurement of the incorporation of [3H]-thymidine. Initially, galectin-10-containing synapses formed between eosinophils and T cells. Subsequently, the plasma membrane of eosinophils began to disintegrate and cap-like accumulations of galectin-10 budded on the eosinophil cell surface. Lastly, eosinophil extracellular traps composed of nuclear DNA and galectin-10 were freed. It was solely the CD16-expressing suppressive eosinophils that formed synapses and eosinophil extracellular traps containing galectin-10. Dissolution of the extracellular traps by DNase I partly abrogated the T cell suppression exerted by eosinophils. Extracellular trap formation has mainly been associated with anti-bacterial defense, but we show a new putative function of these cellular formations, as mediators of T cell suppression by enabling the release of galectin-10 from eosinophils.

The most common tick-borne human disease in Norway is Lyme borreliosis. Ticks in Norway also harbour less known disease-causing agents such as Candidatus Neoehrlichia mikurensis, Borrelia miyamotoi and Rickettsia helvetica. However, human infections caused by these pathogens have never been described in Norway. The main aims of the study were to evaluate the contribution of several tick-borne bacterial agents, other than Borrelia burgdorferi sensu lato, to zoonotic diseases in Norway and to determine their clinical pictures. Blood samples from 70 symptomatic tick-bitten adults from the Agder counties in southern Norway were screened for seven tick-borne pathogens by using a commercial multiplex PCR-based method and by singleplex real-time PCR protocols. Most patients (65/70) presented with a rash clinically diagnosed as erythema migrans (EM). The most frequently detected pathogen DNA was from Ca. N. mikurensis and was found in the blood of 10% (7/70) of the patients. The Ca. N. mikurensis-infected patients presented with an EM-like rash as the only symptom. B. burgdorferi s.l. DNA was present in the blood of 4% (3/70) of the study participants. None had detectable Anaplasma phagocytophilum, B. miyamotoi, Rickettsia typhus group or spotted fever group, Francisella tularensis, Coxiella burnetii or Bartonella spp. DNA in the blood. The commercially available multiplex PCR bacteria flow chip system failed to identify half of the infected patients detected by corresponding real-time PCR protocols. The recovery of Ca. N. mikurensis DNA was higher in the pellet/plasma fraction of blood than from whole blood. To conclude, Ca. N. mikurensis appeared to be the etiological agent in patients with EM in a surprisingly large fraction of tick-bitten persons in the southern part of Norway.

Background Eosinophilic esophagitis (EoE) afflicts both children and adults. It has been debated whether pediatric EoE and adult EoE represent different disease entities. The objectives of this study were to determine whether the blood eosinophil molecular pattern of children with EoE is (i) distinct from that of healthy children; and (ii) different from that of adults with EoE. Methods Blood eosinophils from children and adults with EoE, and healthy controls, were analyzed with flow cytometry regarding levels of CD23, CD44, CD54, CRTH2, FOXP3, and galectin-10. Eosinophil FOXP3 and galectin-10 mRNA levels were determined by qPCR. The data were analyzed using a multivariate method of pattern recognition. Results An eosinophil molecular pattern capable of distinguishing children with EoE from control children was identified. A smaller fraction of eosinophils from children with EoE expressed CD44 and a larger fraction expressed CRTH2 than the controls. Eosinophils from children with EoE also had higher levels of galectin-10 mRNA and lower levels of FOXP3 mRNA. The eosinophils from children with EoE had lower levels of surface CD54 and of FOXP3 mRNA compared with the eosinophils from the adult patients. A key finding was the detection in healthy individuals of age-related differences in the levels of several eosinophil markers. Conclusions Children with EoE can be distinguished from healthy children based on the molecular patterns of their blood eosinophils. Age-related physiologic differences in eosinophil molecular patterns may partly explain the different blood eosinophil phenotypes in children vs adults with EoE.

Allergy and other immune-mediated diseases are more frequently reported in children who have undergone liver transplantation. Furthermore, autoantibodies are also prevalent, suggesting a state of immune dysregulation in these patients. Whether or not these processes occur simultaneously in the same individual has not been studied previously.A cohort of 43 children who had undergone liver transplantation for nonautoimmune liver disease at median age of 1.3 years was investigated for allergy and autoimmune disease. Sensitization to food and inhalant allergens was assessed, and autoantibodies were measured.The prevalence of food allergy was 26% and that of respiratory allergy was 23%, whereas 33% and 26% of the subjects were sensitized to food and inhalant allergens, respectively. Autoimmune disease (ie, autoimmune hepatitis) occurred in a single individual (2%), whereas autoantibodies were present in 44% of the children. Food allergy and autoantibodies occurred concomitantly in 19% of the children, which was almost twice the frequency expected by chance (11%, P = 0.04). Respiratory allergy and the presence of autoantibodies were unrelated (12% concurrence versus the expected 10%, P = 0.73). In the logistic regression analysis, autoantibody formation was associated with discontinued immunosuppression and food allergy, with odds ratios of 13 (P = 0.01) and 7.1 (P = 0.03), respectively.In contrast to respiratory allergy, food allergy and autoantibody formation occurred together in the same children who underwent liver transplantation at a frequency higher than would be expected by chance. This may reflect an underlying immune dysregulation that impairs immune tolerance to both food allergens and autoantigens.

Candidatus (Ca.) Neoehrlichia mikurensis is the cause of neoehrlichiosis, an emerging tick-borne infectious disease characterized by fever and vascular events. The bacterium belongs to the Anaplasmataceae, a family of obligate intracellular pathogens, but has not previously been cultivated, and it is uncertain which cell types it infects. The goals of this study were to cultivate Ca. N. mikurensis in cell lines and to identify possible target cells for human infection. Blood components derived from infected patients were inoculated into cell lines of both tick and human origin. Bacterial growth in the cell cultures was monitored by real-time PCR and imaging flow cytometry. Ca. N. mikurensis was successfully propagated from the blood of immunocompromised neoehrlichiosis patients in two Ixodes spp. tick cell lines following incubation periods of 7–20 weeks. Human primary endothelial cells derived from skin microvasculature as well as pulmonary artery were also susceptible to infection with tick cell-derived bacteria. Finally, Ca. N. mikurensis was visualized within circulating endothelial cells of two neoehrlichiosis patients. To conclude, we report the first successful isolation and propagation of Ca. N. mikurensis from clinical isolates and identify human vascular endothelial cells as a target of infection.

Background Pneumocystis jirovecii pneumonia (PCP) is one of the most common HIV-related opportunistic infections. The diagnosis of PCP is based on analyses from respiratory tract specimens which may require the invasive procedure of a diagnostic bronchoscopy. The objective of this study was to evaluate the diagnostic potential of Pneumocystis jirovecii PCR in serum combined with the 1,3-β-D-glucan (betaglucan) test for the diagnosis of PCP in HIV-infected patients. Methods This was a retrospective case-control study including serum samples from 26 HIV-infected patients with PCP collected within 5 days prior to the start of PCP treatment, 21 HIV-infected control subjects matched by blood CD4+ cell counts, and 18 blood donors. The serum samples were analyzed for Pneumocystis jirovecii PCR and betaglucan. The reference standard for PCP was based on previously described microbiological and clinical criteria. Results All patients with PCP had detectabe Pneumocystis jirovecii DNA in serum yielding a sensitivity for the Pneumocystis jirovecii PCR assay in serum of 100%. All blood donors had negative Pneumocystis PCR in serum. The specificity when testing HIV-infected patients was 71%, but with a PCR Cycle threshold (Ct) value of 34 as cut-off the specificity was 90%. At a putative pretest probaility of 20%, the negative and positive predictive value for the Pneumocystis PCR assay in serum was 0.99 and 0.71, respectively. Betaglucan with cut-off level 200 pg/ml combined with a positive Pneumocystis jirovecii PCR result had sensitivity and specificity of 92 and 90%, respectively. The concentration of Pneumocystis jirovecii DNA in serum samples, expressed by the PCR Ct values, correlated inversely to the betaglucan levels in serum. Conclusion In this case-control study including 70% of all HIV-infected patients with PCP treated at Sahlgrenska University Hospital during a time period of 13 years, Pneumocystis PCR analysis on serum samples had a very high sensitivity and negative predictive value for the diagnosis of PCP in HIV-infected patients. A serum-based diagnostic procedure either based on Pneumocystis jirovecii PCR alone or in combination with betaglucan analysis may thus be feasible and would facilitate the care of HIV-infected patients with suspected PCP.

Summary Eosinophilic esophagitis (EoE) is an antigen-driven T cell-mediated chronic inflammatory disease where food and environmental antigens are thought to have a role. Human eosinophils express the immunoregulatory protein galectin-10 and have T cell suppressive capacity similar to regulatory T cells (Tregs). We hypothesized that one function of eosinophils in EoE might be to regulate the T cell-driven inflammation in the oesophagus. This was tested by evaluating the suppressive capacity of eosinophils isolated from the blood of adult EoE patients in a mixed lymphocyte reaction. In addition, eosinophilic expression of forkhead box protein 3 (FOXP3), the canonical transcription factor of Tregs, was determined by conventional and imaging flow cytometry, quantitative polymerase chain reaction (qPCR), confocal microscopy and immunoblotting. It was found that blood eosinophils from EoE patients had T cell suppressive capacity, and that a fraction of the eosinophils expressed FOXP3. A comparison of EoE eosinophils with healthy control eosinophils indicated that the patients' eosinophils had inferior suppressive capacity. Furthermore, a higher percentage of the EoE eosinophils expressed FOXP3 protein compared with the healthy eosinophils, and they also had higher FOXP3 protein and mRNA levels. FOXP3 was found in the cytosol and nucleus of the eosinophils from both the patients and healthy individuals, contrasting with the strict nuclear localization of FOXP3 in Tregs. To conclude, these findings suggest that the immunoregulatory function of eosinophils may be impaired in EoE.

The tick-borne bacterium Candidatus (Ca.) Neoehrlichia (N.) mikurensis is a cause of "fever of unknown origin" because this strict intracellular pathogen escapes detection by routine blood cultures. Case reports suggest that neoehrlichiosis patients may display serological reactivity to Anaplasma (A.) phagocytophilum. Since Anaplasma serology is part of the diagnostic work-up of undetermined fever in European tick-exposed patients, we wanted to investigate (1) the prevalence of A. phagocytophilum seropositivity among neoehrlichiosis patients, (2) the frequency of misdiagnosed neoehrlichiosis patients among A. phagocytophilum seropositive patients, and (3) the frequency of A. phagocytophilum and Ca. N. mikurensis co-infections. Neoehrlichiosis patients (n = 18) were analyzed for A. phagocytophilum IgM and IgG serum antibodies by indirect immunofluorescence assay. Serum samples from suspected anaplasmosis patients (n = 101) were analyzed for bacterial DNA contents by singleplex PCR specific for A. phagocytophilum and Ca. N. mikurensis, respectively. One fifth of the neoehrlichiosis patients (4/18) were seropositive for IgM and/or IgG to A. phagocytophilum at the time of diagnosis. Among the patients with suspected anaplasmosis, 2% (2/101) were positive for Ca. N. mikurensis by PCR whereas none (0/101) had detectable A. phagocytophilum DNA in the serum. To conclude, patients with suspected anaplasmosis may in fact have neoehrlichiosis. We found no evidence of A. phagocytophilum and Ca. N. mikurensis co-infections in humans with suspected anaplasmosis or confirmed neoehrlichiosis.

The prevalence of Candidatus Neoehrlichia mikurensis infection was determined in 102 persons bitten by ticks in Sweden. Two infected women had erythematous rashes; 1 was co-infected with a Borrelia sp., and the other showed seroconversion for Anaplasma phagocytophilum. Both patients had increased levels of Neoehrlichia DNA and serum cytokines for several months.

We prospectively evaluated a combination of fungal biomarkers in adult haematology patients with focus on their clinical utility at different time points during the course of infection. In total, 135 patients were monitored once to twice weekly for serum (1-3)-s-d-glucan (BG), galactomannan (GM), bis-methyl-gliotoxin and urinary d-arabinitol/l-arabinitol ratio. In all, 13 cases with proven or probable invasive fungal disease (IFD) were identified. The sensitivity of BG and GM at the time of diagnosis (TOD) was low, but within 2 weeks from the TOD the sensitivity of BG was 92%. BG >800 pg/mL was highly specific for IFD. At a pre-test probability of 12%, both BG and GM had negative predictive values (NPV) >0.9 but low positive predictive values (PPV). In a subgroup analysis of patients with clinically suspected IFD (pre-test probability of 35%), the NPV was lower, but the PPV for BG was 0.86 at cut-off 160 pg/mL. Among IFD patients, 91% had patterns of consecutively positive and increasing BG levels. Bis-methyl-gliotoxin was undetectable in 15 patients with proven, probable and possible IA. To conclude, BG was the superior fungal marker for IFD diagnosis. Quantification above the limit of detection and graphical evaluation of the pattern of dynamics are warranted in the interpretation of BG results.

Neoehrlichiosis is an infectious disease caused by the tick-borne bacterium "Candidatus Neoehrlichia mikurensis". Splenectomy and rituximab therapies are risk factors for severe neoehrlichiosis. Our aim was to examine if neoehrlichiosis patients had low levels of natural IgM antibodies and/or were hypogammaglobulinemic, and if such deficiencies were associated with asplenia and vascular complications.Neoehrlichiosis patients (n = 9) and control subjects (n = 10) were investigated for serum levels of IgG, IgA, and IgM, and for levels of natural IgM antibodies to pneumococcal polysaccharides (6B, 14), and to the malondialdehyde acetaldehyde epitope of oxidized LDL. The multivariate method Projection to Latent Structures was used to analyze the data.The levels of natural IgM antibodies of various specificities were decreased or not measurable in half of the studied patients with neoehrlichiosis. Only one patient and one control subject were hypogammaglobulinemic. An inverse relationship was noted between the levels of natural IgM antibodies and the development of deep vein thrombosis. Unexpectedly, no association was seen between having or not having a spleen and the levels of natural IgM antibody levels in the circulation.Neither hypogammaglobulinemia nor lack of natural IgM antibodies alone predisposes for severe neoehrlichiosis. The importance of the spleen in the immune defence against Ca. N. mikurensis probably lies in its capacity to generate or maintain specific antibodies.

Eosinophilia has been associated with less severe graft-versus-host disease (GVHD), but the underlying mechanism is unknown. We hypothesized that eosinophils diminish allogeneic T cell activation in patients with chronic GVHD. The capacity of eosinophils derived from healthy subjects and hematopoietic stem cell (HSC) transplant recipients, with or without chronic GVHD, to reduce allogeneic T cell proliferation was evaluated using a mixed leukocyte reaction. Eosinophil-mediated inhibition of proliferation was observed for the eosinophils of both healthy subjects and patients who underwent HSC transplantation. Eosinophils from patients with and without chronic GVHD were equally suppressive. Healthy eosinophils required cell-to-cell contact for their suppressive capacity, which was directed against CD4+ T cells and CD8+ T cells. Neither eosinophilic cationic protein, eosinophil-derived neurotoxin, indoleamine 2,3-dioxygenase, or increased numbers of regulatory T cells could account for the suppressive effect of healthy eosinophils. Real-time quantitative PCR analysis revealed significantly increased mRNA levels of the immunoregulatory protein galectin-10 in the eosinophils of both chronic GVHD patients and patients without GVHD, as compared with those from healthy subjects. The upregulation of galectin-10 expression in eosinophils from patients suggests a stimulatory effect of HSC transplantation in itself on eosinophilic galectin-10 expression, regardless of chronic GVHD status. To conclude, eosinophils from HSC transplant recipients and healthy subjects have a T cell suppressive capacity.

Swallowed topical corticosteroids are the standard therapy for eosinophilic esophagitis (EoE) in adults. Eosinophils in the blood of untreated EoE patients have an activated phenotype. Our aim was to determine if corticosteroids restore the phenotype of eosinophils to a healthy phenotype and if certain cell-surface molecules on blood eosinophils correlate with eosinophilic infiltration of the esophagus. Levels of eight surface markers on eosinophils from treated and untreated EoE patients were determined by flow cytometry and analyzed using multivariate methods of pattern recognition. Corticosteroid-treated EoE patients' eosinophils had decreased levels of CD18 compared to both untreated patients and healthy controls, but maintained their activated phenotype. CD18 expression correlated positively with eosinophil numbers in the esophagus and promoted the adherence of eosinophils to ICAM-1, ICAM-2, and to endothelial cells. The diminished expression of CD18 may be one mechanism behind the reduced entry of eosinophils into the esophagus in corticosteroid-treated EoE patients.

Eosinophils have the capacity to regulate the function of T cell subsets. Our aim was to test the hypothesis of the existence of a regulatory subset of eosinophils. Human eosinophils were incubated with T cells that were stimulated with allogeneic leukocytes or CD3/CD28 cross-linking. After 2 d of coculture, 11% of the eosinophils gained CD16 expression. A CD16hi subset of eosinophils, encompassing 1–5% of all eosinophils, was also identified in the blood of healthy subjects. FACS sorting showed that these CD16hi eosinophils were significantly stronger suppressors of T cell proliferation than were conventional CD16neg eosinophils. Human eosinophils contain stores of the immunoregulatory protein galectin-10. We found that Ab-mediated neutralization of galectin-10 partially abrogated the suppressive function of the eosinophils. Moreover, recombinant galectin-10 by itself was able to suppress T cell proliferation. Finally, we detected galectin-10–containing immune synapses between eosinophils and lymphocytes. To conclude, we describe a subset of suppressive eosinophils expressing CD16 that may escape detection because CD16-based negative selection is the standard procedure for the isolation of human eosinophils. Moreover, we show that galectin-10 functions as a T cell–suppressive molecule in eosinophils.

The black-pigmented fungus Exophiala dermatitidis is considered to be a harmless colonizer of the airways of cystic fibrosis (CF) patients. The aim of this study was to establish the recovery rate of E. dermatitidis in respiratory specimens from CF patients, transplant recipients, and subjects with other respiratory disorders in Sweden. Second, we wished to determine if particular clinical traits were associated with E. dermatitidis colonization of the airways and the antifungal susceptibility profiles of Exophiala strains. Sputum and bronchoalveolar lavage samples ( n = 492) derived from 275 patients were investigated. E. dermatitidis was isolated in respiratory specimens from 19% (18/97) of the CF patients but in none of the other patient categories. All isolates were recovered after 6 to 25 days of incubation on erythritol-chloramphenicol agar (ECA) medium. Morphological and genetic analyses confirmed species identity. Pancreatic insufficiency was positively associated with the presence of E. dermatitidis in sputum samples ( P = 0.0198). Antifungal susceptibility tests demonstrated that voriconazole and posaconazole had the lowest MICs against E. dermatitidis . In conclusion, E. dermatitidis is a frequent colonizer of the respiratory tract in CF patients in Sweden and appears to be associated with more advanced disease. Whether E. dermatitidis is pathogenic remains to be elucidated.

The performance of a new commercially available duplex PCR, which combines pan-dermatophyte PCR with a Trichophyton rubrum-specific PCR, was evaluated. This Dermatophyte PCR kit, which requires one day for laboratory diagnosis, was compared with the conventional methods of microscopy and culture that necessitate up to 4 weeks for final diagnosis of dermatophytosis. We studied 177 nail samples from patients with suspected onychomycosis by fluorescence microscopy (blankophore), cultures and the Dermatophyte PCR kit. More samples were positive by PCR (78/177, 44%) than by culture (59/177, 34%). T. rubrum was present in 95% of all culture-positive nail specimens, which was confirmed by PCR in 55/56 specimens. The positive predictive value, negative predictive value, specificity and sensitivity of the duplex PCR was 93%, 87%, 94% and 85%, respectively, when confirmed by positive culture, microscopy or both. Due to its sensitivity, specificity and rapidity, we conclude that this PCR is an attractive method for routine investigation of nail dermatophytosis in a clinical setting.

An immunocompromised patient presented with febrile episodes, an erysipelas-like rash, and thromboembolic complications. Amplification of 16S rRNA gene sequences from blood and sequence analysis revealed “ Candidatus Neoehrlichia mikurensis.” We report the first case of human disease caused by “ Ca . Neoehrlichia mikurensis.”

The present study aimed to improve the rate of detection of blood-borne microbes by using PCRs with pan-bacterial and Candida specificity. Seventeen per cent of the blood samples (n = 178) collected from 107 febrile patients with haematological malignancies were positive using standard culture (BacT/Alert system). Candida PCR was positive in 12 patients, only one of whom scored culture-positive. Bacterial PCR using fresh blood samples was often negative, but the detection rate increased when the blood was pre-incubated for 2 days. These data indicate that PCR assays might be a complement for the detection of blood-borne opportunists in immunocompromised haematology patients.

Clara cell 16-kDa (CC16) is an anti-inflammatory protein chiefly produced in the lung epithelium. CC16 has been shown to inhibit the migration of rabbit neutrophils and human monocytes toward the formyl peptide N-formyl-methionine-leucin-phenylalanin (fMLF). Eosinophils migrate towards prostaglandin D2 (PGD(2)) and CC16 has been shown to bind to PGD(2). Therefore we investigated if CC16 could inhibit the migration of human eosinophils and neutrophils towards fMLF and/or PGD(2). Migration of eosinophils and neutrophils was assessed in a microplate migration system using specific ligands and receptor antagonists. CC16 inhibited the migration of eosinophils and neutrophils toward fMLF, which is likely to result from the interaction of CC16 with members of the formyl-peptide receptor family. However, CC16 did not inhibit eosinophil migration towards PGD(2). We therefore propose that CC16 may down-modulate the entry of human eosinophils and neutrophils into the airways during inflammation in the lung.

The anti-inflammatory drug piroxicam has been reported to affect the production of reactive oxygen species in phagocytes. This anti-inflammatory effect is thought to be mediated through inhibition of cyclooxygenase (COX), an enzyme important for prostaglandin synthesis. We have compared the effects of piroxicam on superoxide production mediated by two closely related G-protein coupled receptors expressed on neutrophils, the formyl peptide receptor (FPR) and the formyl peptide receptor like 1 (FPRL1). Neutrophils were stimulated with agonists that bind specifically to FPR (the peptide ligand N-formyl-Met-Leu-Phe, fMLF) or FPRL1 (the peptide ligand Trp-Lys-Tyr-Met-Val-L-Met-NH(2), WKYMVM) or both of these receptors (the peptide ligand Trp-Lys-Tyr-Met-Val-D-Met-NH(2), WKYMVm). Piroxicam reduced the neutrophil superoxide production induced by the FPR agonist but had no significant effect on the FPRL1 induced response. Neutrophil intracellular calcium changes induced by the agonist WKYMVm (that triggers both FPR and FPRL1) were only inhibited by piroxicam when the drug was combined with the FPRL1 specific antagonist, Trp-Arg-Trp-Trp-Trp-Trp (WRW(4)), and this was true also for the inhibition of superoxide anion release. Receptor-binding analysis showed that the fluorescently labelled FPR specific ligand N-formyl-Nle-Leu-Phe-Nle-Tyr-Lys (fNLFNYK), was competed for in a dose-dependent manner, by the FPR ligand fMLF and as well as by piroxicam. We show that piroxicam inhibits the neutrophil responses triggered through FPR, but not through FPRL1 and this inhibition is due to a reduced binding of the activating ligand to its cell surface receptor.

Patients with multiple myeloma and other B cell disorders respond poorly to pneumococcal vaccination. Vaccine responsiveness is commonly determined by measuring pneumococcal serotype-specific antibodies by enzyme-linked immunosorbent assay (ELISA), by a functional opsonophagocytosis assay (OPA), or by both assays. We compared the two methods in vaccinated elderly patients with multiple myeloma, Waldenstrom's macroglobulinemia, and monoclonal gammopathy of undetermined significance (MGUS). Postvaccination sera from 45 patients ( n = 15 from each patient group) and 15 control subjects were analyzed by multiplexed OPA for pneumococcal serotypes 4, 6B, 14, and 23F, and the results were compared to IgG and IgM antibody titers measured by ELISA. While there were significant correlations between pneumococcal OPA and IgG titers for all serotypes among the control subjects (correlation coefficients [ r ] between 0.51 and 0.85), no significant correlations were seen for any of the investigated serotypes in the myeloma group ( r = −0.18 to 0.21) or in the group with Waldenstrom's macroglobulinemia (borderline significant correlations for 2 of 4 serotypes). The MGUS group resembled the control group by having good agreement between the two test methods for 3 of 4 serotypes ( r = 0.53 to 0.80). Pneumococcal postvaccination IgM titers were very low in the myeloma patients compared to the other groups and did not correlate with the OPA results. To summarize, our data indicate that ELISA measurements may overestimate antipneumococcal immunity in elderly subjects with B cell malignancies and that a functional antibody test should be used specifically for myeloma and Waldenstrom's macroglobulinemia patients.

Background Graft-versus-host disease (GVHD) that develops after intestinal or multivisceral transplantation is difficult to diagnose and is associated with high morbidity and mortality. Material and Methods The objectives of this study were to investigate the incidence, clinical picture, risk factors, and outcome of GVHD in a Scandinavian cohort of patients who underwent intestinal or multivisceral transplantation during a period of 16 years (1998–2014). All transplanted patients (n = 26) were retrospectively analyzed with respect to donor- and recipient-derived risk factors. The diagnosis of GVHD was based on clinical signs, chimerism analyses of leukocytes, and histopathologic findings in biopsy specimens. Results Five of 26 patients (19%) were diagnosed with GVHD, of which three had skin GVHD, one had skin and bone marrow GVHD, and one had passenger leukocyte syndrome. Only multivisceral-transplanted patients developed GVHD. Risk factors for development of GVHD were an underlying tumor diagnosis and neoadjuvant chemo- or brachytherapy administered before intestinal transplantation. All patients were given high-dose corticosteroids as first line treatment for their GVHD, and all survived their episodes of GVHD. Conclusions The risk of GVHD appears to be increased in recipients of multivisceral transplantations who received chemotherapy due to an underlying malignancy. The reasons may be the large amount of lymphoid tissue in these types of grafts, and the cytotoxic effects of the malignancy and chemotherapy on healthy recipient tissues. These patients should be monitored closely for the development of GVHD.

Eosinophilic granulocytes are found in tissues with an interface with the external environment, such as the gastrointestinal, genitourinary and respiratory tracts. These leucocytes have been associated with tissue damage in a variety of diseases. The aim of this study was to evaluate whether necrotic epithelial cells can activate eosinophils. The danger theory postulates that cells of the innate immune system primarily recognize substances that signal danger to the host. We damaged epithelial cell lines derived from the genital (HeLa cells), respiratory (HEp-2 cells) and intestinal tracts (HT29 cells) and assessed their capacity to cause eosinophilic migration, release of putative tissue-damaging factors, such as eosinophil peroxidase (EPO) and eosinophil cationic protein (ECP), as well as secretion of tissue-healing factors, e.g. fibroblast growth factors (FGF)-1 and -2 and transforming growth factor (TGF)-beta1. We found that necrotic intestinal cells induced chemotaxis in human eosinophils. EPO release was elicited in eosinophils stimulated with necrotic cells derived from all cell lines, as well as from viable HEp-2 and HT29 cells. Release of ECP was only seen in eosinophils incubated with necrotic intestinal or genital cells, not viable ones. Both necrotic intestinal and genital cells elicited FGF-2 secretion from eosinophils. TGF-beta1 was released from eosinophils exposed to viable and necrotic HT29 cells. These findings indicate that eosinophils are able to recognize and be activated by danger signals released from damaged epithelial cells, which may be of importance in understanding the role of eosinophils in the various inflammatory conditions in which they are involved.

Allergic diseases are characterized by the presence of eosinophils, which are recruited to the affected tissues by chemoattractants produced by T cells, mast cells and epithelium. Our objective was to evaluate if allergens can directly activate human eosinophils. The capacity of purified allergen extracts to elicit eosinophil chemotaxis, respiratory burst, degranulation and up-regulation of the adhesion molecule complement receptor 3 (CR3) was determined in eosinophils isolated from healthy blood donors. Eosinophils stimulated with an extract from house dust mite (HDM) released the granule protein major basic protein (MBP) and up-regulated the surface expression of CR3. Cat allergen extracts also induced the up-regulation of CR3, but not the release of MBP; instead cat, as well as birch and grass allergens, elicited the release of eosinophil peroxidase (EPO). In addition, grass pollen extract caused the secretion of MBP. None of the allergens stimulated eosinophilic cationic protein release, nor production of free oxygen radicals. Both HDM and birch extracts were chemotactic for eosinophils. These findings establish that common aeroallergens can directly activate eosinophils in vitro. We propose that eosinophil activation in vivo is not exclusively mediated by cytokines and chemokines of the allergic inflammatory reaction, but could partly be the result of direct interaction between allergens and eosinophils.

Investigations were carried out to study the production of factors associated with the innate immune response in the systemic and mucosal compartments in adults and children infected withVibrio choleraeO1 andV. choleraeO139. The levels of nonspecific mediators of the innate defense system, i.e., prostaglandin E2(PGE2), leukotriene B4(LTB4), and lactoferrin (Lf), as well as myeloperoxidase (MPO), were elevated at the acute stage of the disease in stools obtained from both O1- and O139-infected adults and children. In the systemic compartment, the levels of Lf were increased after onset of disease, which in children remained elevated up to convalescence compared to the healthy controls. Increased concentrations of C-reactive protein were seen in the sera of adult cholera patients at the acute stage of infection. Elevated levels of the nitric oxide (NO·) metabolites (nitrite and nitrate [NO2−and NO3−]) were detected in plasma but not in urine. The activity of the scavenger of reactive oxygen species, superoxide dismutase, was higher in the plasma of adults immediately after the onset of disease, suggesting that an active scavenging of reactive oxygen species was taking place. The concentration of 8-iso-prostaglandin F2αremained unchanged in the systemic and mucosal compartments in the study subjects. After the recovery of patients from cholera, the concentration of the majority of the metabolites decreased to baseline levels by day 30 after the onset of infection. Immunohistochemical staining showed increased tissue expression of MPO, Lf, and inducible nitric oxide synthase at the acute stage in the duodenal biopsies of adults and rectal biopsies obtained from children with cholera. Very little difference was seen in the levels of the different inflammatory mediators in patients infected withV. choleraeO1 or the encapsulatedV. choleraeO139. In summary, these results suggest that elevated concentrations of Lf, MPO, PGE2, LTB4, and NO·, as well as other metabolites, during the acute stage of the disease indicate that the innate defense system, as well as the inflammatory process, is activated in both adults and pediatric patients infected withV. choleraeO1 and O139.

Detection of the fungal cell wall component beta-glucan (BG) in serum is increasingly used to diagnose invasive fungal infections (IFI), but its optimal use in hematology patients with high risk of IFI is not well defined. We retrospectively analyzed the diagnostic accuracy, optimal cut-off level, and potential confounding factors of BG reactivity. The inclusion criteria were: adult patients with hematologic disease who were admitted to the hematology ward during the 2-year study period and who had two or more consecutive BG assays performed. In total, 127 patients were enrolled. Thirteen patients with proven or probable IFI, as defined by the 2008 European Organization for Research and Treatment of Cancer/Mycoses Study Group (EORTC/MSG) criteria, were identified. Receiver operating characteristic (ROC) curve analysis showed a high overall diagnostic performance (area under the ROC curve = 0.98) and suggested an optimal cut-off level of 158 pg/ml, with a sensitivity and a specificity of 92 % and 96 %, respectively. Multiway analysis of variance indicated that treatment with pegylated asparaginase (p

While increased numbers of eosinophils may be detected in patients with graft-versus-host disease (GVHD) following hematopoietic stem cell transplantation, it is not known if eosinophils play a role in GVHD. The aims of this study were to determine: whether eosinophils are activated during GVHD; whether the patterns of activation are similar in acute and chronic GVHD; and the ways in which systemic corticosteroids affect eosinophils. Transplanted patients (n = 35) were investigated for eosinophil numbers and the expression levels of 16 eosinophilic cell surface markers using flow cytometry; all the eosinophil data were analyzed by the multivariate method OPLS-DA. Different patterns of molecule expression were observed on the eosinophils from patients with acute, chronic, and no GVHD, respectively. The molecules that provided the best discrimination between acute and chronic GVHD were: the activation marker CD9; adhesion molecules CD11c and CD18; chemokine receptor CCR3; and prostaglandin receptor CRTH2. Patients with acute or chronic GVHD who received systemic corticosteroid treatment showed down-regulation of the cell surface markers on their eosinophils, whereas corticosteroid treatment had no effect on the eosinophil phenotype in the patients without GVHD. In summary, eosinophils are activated in GVHD, display different activation profiles in acute and chronic GVHD, and are highly responsive to systemic corticosteroids.

Background Candidatus Neoehrlichia mikurensis is a newly discovered noncultivatable bacterium spread among ticks and rodents in Europe and Asia that can infect humans, particularly immunocompromised patients. Methods We compiled clinical and laboratory data from 11 patients with hematological malignances or autoimmune diseases who were diagnosed with Candidatus N. mikurensis infection in Europe 2010-2013. Both published (6) and unpublished cases (5) were included. Results The patients had a median age of 67, were mostly male (8/11), and resided in Sweden, Switzerland, Germany, and the Czech Republic. All but one had ongoing or recent immune suppressive treatment and a majority were splenectomized (8/11). Less than half of them recalled tick exposure. The most frequent symptoms were fever (11/11), localized pain afflicting muscles and/or joints (8/11), vascular and thromboembolic events (6/11), that is, deep vein thrombosis (4), transitory ischemic attacks (2), pulmonary embolism (1), and arterial aneurysm (1). Typical laboratory findings were elevated C-reactive protein, leukocytosis with neutrophilia, and anemia. Median time from onset of symptoms to correct diagnosis was 2 months. In at least 4 cases, the condition was interpreted to be due to the underlying disease, and immunosuppressive therapy was scheduled. All patients recovered completely when doxycycline was administered. Conclusions Candidatus N. mikurensis is an emerging tick-borne pathogen that may give rise to a systemic inflammatory syndrome in persons with hematologic or autoimmune diseases that could be mistaken for recurrence of the underlying disease and/or unrelated arteriosclerotic vascular events. Awareness of this new pathogen is warranted among rheumatologists, hematologists, oncologists, and infectious disease specialists.

BACKGROUND: Invasive infections and sterile tissue damage can both give rise to systemic inflammation with fever and production of inflammatory mediators. This makes it difficult to diagnose infections in patients who are already inflamed, e.g. due to cell and tissue damage. For example, fever in patients with hematological malignancies may depend on infection, lysis of malignant cells, and/or chemotherapy-induced mucosal damage. We hypothesized that it would be possible to distinguish patterns of inflammatory mediators characterizing infectious and non-infectious causes of inflammation, respectively. Analysis of a broad range of parameters using a multivariate method of pattern recognition was done for this purpose. METHODS: In this prospective study, febrile (>38°C) neutropenic patients (n = 42) with hematologic malignancies were classified as having or not having a microbiologically defined infection by an infectious disease specialist. In parallel, blood was analyzed for 116 biomarkers, and 23 clinical variables were recorded for each patient. Using O-PLS (orthogonal projection to latent structures), a model was constructed based on these 139 variables that could separate the infected from the non-infected patients. Non-discriminatory variables were discarded until a final model was reached. Finally, the capacity of this model to accurately classify a validation set of febrile neutropenic patients (n = 10) as infected or non-infected was tested. RESULTS: A model that could segregate infected from non-infected patients was achieved based on discrete differences in the levels of 40 variables. These variables included acute phase proteins, cytokines, measures of coagulation, metabolism, organ stress and iron turn-over. The model correctly identified the infectious status of nine out of ten subsequently recruited febrile neutropenic hematology patients. CONCLUSIONS: It is possible to separate patients with infectious inflammation from those with sterile inflammation based on inflammatory mediator patterns. This strategy could be developed into a decision-making tool for diverse clinical applications.

Shigella infections lead to severe inflammation associated with destruction of colonic mucosa. We assessed the effect of in vivo blockade of CD14 on the outcome of experimental Shigella infection in rabbits. A total of 17 rabbits were divided into two groups: 8 received a single i.v. dose of anti-rabbit CD14 monoclonal antibody prior to infection with an invasive Shigella flexneri strain; the remainder served as controls. The anti-CD14-treated rabbits exhibited more severe tissue destruction and a 50-fold increase in bacterial invasion of the intestinal mucosa when compared to controls. Similar numbers of polymorphonuclear leukocytes were recruited to the intestinal mucosa in both groups despite the massive bacterial invasion seen in the CD14-blocked group. No statistically significant differences were seen in levels of IL-1β nor in the ratio of IL-1RA/IL-1β for either group. In contrast, higher quantities of TNF-α were observed in the CD14-blocked group. To conclude, anti-CD14 treatment had a detrimental effect on the capacity of Shigella-infected animals to clear the infection.

Immune responses against enterotoxigenic Escherichia coli (ETEC) were examined in Bangladeshi adults with naturally acquired disease and compared to responses in age-matched Bangladeshi volunteers who had been orally immunized with a vaccine consisting of inactivated ETEC bacteria expressing different colonization factor antigens (CFs) and the B subunit of cholera toxin. B-cell responses in duodenal biopsy samples, feces, intestinal washings, and blood were determined. Because most of the patients included in the study were infected with ETEC expressing CS5, immune responses to this CF were studied most extensively. Vaccinees and patients had comparable B-cell responses against this antigen in the duodenum: the median numbers of antibody-secreting cells (ASC) were 3,300 immunoglobulin A (IgA) ASC/10 7 mononuclear cells (MNC) in the patient group ( n = 8) and 1,200 IgA ASC/10 7 MNC in the vaccinees ( n = 13) (not a significant difference). Similarly, no statistically significant differences were seen in the levels of duodenal B cells directed against enterotoxin among vaccinees and patients. A comparison of the capacities of the various methods used to assess mucosal immune responses revealed a correlation between numbers of circulating B cells and antibody levels in saponin extracts of duodenal biopsy samples ( r = 0.58; n = 13; P = 0.04) after vaccination. However, no correlation was seen between blood IgA ASC and duodenal IgA ASC after two doses of vaccine. Still, a correlation between numbers of CF-specific B cells in blood sampled from patients early during infection and numbers of duodenal B cells collected 1 week later was apparent ( r = 0.70; n = 10; P = 0.03).

We have examined whether oral immunization of adult Swedish volunteers with a prototype enterotoxigenic Escherichia coli vaccine would induce antigen-specific T-cell responses in blood. Volunteers were given one to three doses of the whole-cell component of the vaccine, which consisted of formalin-inactivated bacteria expressing the fimbrial colonization factor antigens I and II. Following immunization, in vitro stimulation of blood mononuclear cells with the colonization factor antigens resulted in modest proliferative responses which were accounted for mainly by CD4+ T cells and, to a lesser extent, by CD8+ T cells. A main finding of this study was that a majority of the orally immunized volunteers had circulating T cells capable of producing large quantities of gamma interferon following in vitro exposure to either of the colonization factor antigens. No interleukin 2 production could be detected in the cell cultures. These results suggest that oral immunization of humans induces the migration of specific mucosal T immunocytes from the intestine into peripheral blood.

Whereas patients with multiple myeloma (MM) have a well-documented susceptibility to infections, this has been less studied in other B-cell disorders, such as Waldenstrom's macroglobulinemia (WM) and monoclonal gammopathy of undetermined significance (MGUS). We investigated the humoral immunity to 24 different pathogens in elderly patients with MM (n= 25), WM (n= 16), and MGUS (n= 18) and in age-matched controls (n= 20). Antibody titers against pneumococci, staphylococcal alpha-toxin, tetanus and diphtheria toxoids, and varicella, mumps, and rubella viruses were most depressed in MM patients, next to lowest in WM and MGUS patients, and highest in the controls. In contrast, levels of antibodies specific for staphylococcal teichoic acid,Moraxella catarrhalis, candida, aspergillus, and measles virus were similarly decreased in MM and MGUS patients. Comparable titers in all study groups were seen againstHaemophilus influenzaetype b (Hib), borrelia, toxoplasma, and members of the herpesvirus family. Finally, a uniform lack of antibodies was noted againstStreptococcus pyogenes, salmonella, yersinia, brucella, francisella, and herpes simplex virus type 2. To conclude, although MM patients displayed the most depressed humoral immunity, significantly decreased antibody levels were also evident in patients with WM and MGUS, particularly againstStaphylococcus aureus, pneumococci, and varicella. Conversely, immunity was retained for Hib and certain herpesviruses in all study groups.

Blood eosinophil numbers may be elevated in allergy, inflammatory bowel disease and eosinophilic esophagitis. The aim of this study was to examine whether circulating eosinophils display distinct phenotypes in these disorders and if different patterns of eosinophilic chemoattractants exist. Blood eosinophils from patients with symptomatic eosinophilic esophagitis (EoE; n = 12), ulcerative colitis (n = 8), airway allergy (n = 10) and healthy controls (n = 10) were enumerated and their surface markers analyzed by flow cytometry. Plasma levels of pro-eosinophilic cytokines were quantified in parallel. Data were processed by multivariate pattern recognition methods to reveal disease-specific patterns of eosinophil phenotypes and cytokines. EoE patients had higher numbers of eosinophils with enhanced expression of CD23, CD54, CRTH2 and CD11c and diminished CCR3 and CD44 expression. Plasma CCL5 was also increased in EoE. Although allergic patients had increased interleukin (IL)-2, IL-3, IL-5 and granulocyte macrophage colony-stimulating factor plasma concentrations, their blood eosinophil phenotypes were indistinguishable from those of healthy controls. Decreased eosinophilic expression of CD11b, CD18, CD44 and CCR3, but no distinctive pattern of eosinophil chemoattractants, characterized ulcerative colitis. We propose that eosinophils acquire varying functional properties as a consequence of distinct patterns of activation signals released from the inflamed tissues in different diseases.