Search

Objective: To explore a panel of serum biomarkers for laboratory diagnosis of pediatric Henoch-Schönlein purpura (HSP)., Methods: The blood white blood cells (WBC) and serum levels of serum amyloid A (SAA), interleukin 6 (IL-6), immunoglobulin A (IgA), immunoglobulin G (IgG), immunoglobulin M (IgM), immunoglobulin E (IgE), C-reactive protein (CRP), complement component 3 (C3), complement component 4 (C4), and ASO (anti-streptolysin O) were detected in 127 patients with Henoch-Schonlein purpura (HSP), 110 cases of septicemia patients, and 121 healthy volunteers. The diagnostic ability of biomarkers selected from HSP and septicemia patients was analyzed by ROC curve. By designing the calculation model, the biomarker index was calculated for laboratory diagnosis of HSP and differential diagnosis between HSP and septicemia., Results: The levels of serum WBC, CRP, IL-6 and SAA in the septicemia patients were significantly higher than those in the control group (p<0.05). Compared with the healthy individuals, serum levels of WBC, CRP, IL-6, SAA, IgA and IgM were significantly increased in patients with HSP (p<0.05). The area under the curve (AUC) of SAA, IgA, IgM, WBC, IL-6, and CRP in the patients with HSP was 0.964, 0.855, 0.849, 0.787, 0.765, and 0.622, respectively. The values of SAA, IgA, IgM, WBC, IL-6, and CRP in septicemia patients were 0.700, 0.428, 0.689, 0.682, 0.891, and 0.853, respectively. Biomarker index=SAA+IgA/4000+IgM/4000×0.4CRPmean valueCRPi . The biomarker index in HSP patients was significantly higher than that of the healthy controls. However, the biomarker index in septicemia patients was significantly lower than the control., Conclusion: The biomarker index of HSP patients is higher than that of the control group. While in the infectious disease represented by septicemia, it is decreased. The detection of biomarker index could exclude the interference of infection as the auxiliary examination to HSP patients., (Copyright © 2017 The Canadian Society of Clinical Chemists. Published by Elsevier Inc. All rights reserved.)

The present study for the first time evaluates the serodiagnostic efficacy of two recombinant antigens namely, listeriolysin O (rLLO) and phosphatidyl-inositol phospholipase C (rPI-PLC). Indirect ELISA with the above recombinant antigens was used on samples collected from bovines (n=106), goats (n=138) and pigs (n=92) having either a history of abortion, emaciation and/or apparently healthy animals. Isolation of Listeria was attempted from the blood samples using USDA-FSIS method. On screening of test sera by rLLO-based ELISA, antibodies against anti-listeriolysin O (ALLO) were observed in goats (22.46%), bovines (15.10%) and pigs (16.31%). As advocated, after adsorption of positive serum samples with streptolysin O (SLO), the seropositivity for ALLO was marginally reduced (p>0.05) in goats (21.73%) and bovines (10.38%), whereas, in pigs the reduction (5.43%) was significant (p<0.05). On the contrary, rPI-PLC-based ELISA revealed higher non-specific seropositivity for antilisterial antibodies in goats (45.65%), bovines (31.13%) and pigs (8.69%). Further, on comparing the seropositivity with isolation rate, of the 16 animals that were culturally-positive for L. monocytogenes, 15 showed ALLO positivity in unadsorbed as well as SLO-adsorbed sera by rLLO-based ELISA, however, rPI-PLC-based ELISA could detect seropositivity in only 5 animals. Moreover, rPI-PLC-based ELISA also showed seropositivity in those animals (7/30) that were culturally positive for other Listeria spp. In conclusion, rLLO can serve as a better antigen than rPI-PLC in ELISA for the serodiagnosis of listeriosis in animals; however, prior adsorption of test sera with SLO is required to avoid false positive results., (Copyright © 2017 Elsevier B.V. All rights reserved.)

The Rostovskii state medical university of Minzdrav of Russia, 344022 Rostov-on-Don, Russia The analysis is applied concerning significance of laboratory techniques of verification of streptococcus infection (bacteriological analysis, detection of anti-streptolysin O in pair serums) in 148 patients with infectious mononucleosis aged from 3 to 15 years. The content of anti-streptolysin O exceeded standard in 41 ± 4.8% of patients with concomitant in acute period and in 49.5 ± 4.9% during period of re-convalescence. This data differed from analogous indicator in patients with negative result of examination on streptococcus infection independently of period of disease (9.3 ± 2.8%). The exceeding of standard of anti-streptolysin O was detected more frequently (t ≥ 2, P ≥ 95%) in patients with isolation of Streptococcus pyogenes (56.9 ± 5.8%) than in patients with Streptococcus viridans (31.2 ± 6.5%). The concentration of anti-streptolysin 0 in patients with concomitant streptococcus infection varied within limits 200-1800 IE/ml. The minimal level of anti-streptolysin O (C = 200 IE/mI) was detected independently of type of isolated Streptococcus and period of disease. The high levels of anti-streptolysin O were observed exclusively in patients with isolation of Streptococcus pyogenes. In blood serum ofpatient with concomitant streptococcus infection (Streptococcus pyogenes + Streptococcus viridans) increasing of level of anti-streptolysin O was detected in dynamics of diseases from minimal (C = 200 IE/ ml) to moderately high (200 < C < 400 IE/mI). It is demonstrated that to identify streptococcus infection in patients with infectious mononucleosis the anamnesis data is to be considered. The complex bacteriological and serological examination ofpatients is to be implemented This is necessary for early detection ofpatients with streptococcus infection and decreasing risk of formation of streptococcus carrier state.

Introduction: The diagnosis of post streptococcal diseases is usually confirmed by immunological tests. Only the antistreptolysin O is usually prescribed by physician. This study aimed to describe the current practice of these requests in Antananarivo., Methods: It was a retrospective and descriptive study conducted at the Para clinic Unit of Immunology at the University Center Hospital of Antananarivo. We analyzed all requests during seven years, from January 2003 to December 2009. We looked at age, gender, and clinical symptoms which led to the request and the result for each request., Results: We retained 4143 requests for antistreptolysin O titration in our study. The mean age of the study participants was 32.9 years with 18.3% of participants being less than 15 years old. The main symptoms leading to the request of this analysis were rheumatologic (41%), followed by neurological (13.9%) and cardiologic symptoms (8.5%) and 19.4% were prescribed for various symptoms. Only 15% of all requests had a value more than 200 U/ml., Conclusion: Our study found that in most of requests, ASO titre levels were not significant.

A highly sensitive and rapid method for the determination of substance P (SP) and streptolysin O (SLO) in human serum is described. The assay is based on enriching the analyte by agglutination/precipitation of immuno-liposomes and enhancing the fluorescence intensity by gramicidin A channels. A mixture of the immuno-liposomes encapsulating a pH-sensitive fluorescence dye BCECF, gramicidin A and a given concentration of SP (or SLO) is preincubated in a solution and captured on anti-SP (or anti-SLO)-modified cover slips, followed by measuring fluorescence images after removing excess liposomes. The method allowed quantifying SP and SLO in the range from sub-pg mL(-1) to pg mL(-1), with detection limits of 0.32 pg mL(-1) and 8 fg mL(-1), respectively. The present method could determine SP and SLO in 50-125 times diluted human serum without any extraction steps. The assay can be completed within 60 min.

Aim: Evaluate informativity of simultaneous determination of antibodies (AB) against extracellular (AB against streptolysin-O-ASL-O) and cellular (IgM against A-polysaccharide - A-PSC) antigens in patients with angina and soft tissue infections caused by serogroup A streptococci (SGA) and identify features of humoral immune response to SGA infection according to infectious process localization. MATERIALS AND METHODS. 2 groups of patients with bacteriologically confirmed SGA infection (50 cases of angina - group 1 and 51 case of soft tissue infection - group 2) were examined for the presence of ASL-O by using Architect ci8200 analyzer (Abbott, USA) and IgM against SGA A-PSC by EIA. RESULTS. In group 1, 23 (46%) individuals were recognized as positive by ASL-O level, and in group 2 - 20 (39%; p>0.05); conditionally significant exceeding of normal values (more than 1.5 times) was detected in 25% of patients of each group. Increased level of antibodies against SGA A-PSC was detected in 43 (86%) patients of group 1, and in 30 (59%) of patients of group 2 (p<0.05). In group 1 exceeding of normal values of anti-A-PSC IgM was noted mostly by 1.5 +/- 0.5 times (74%). In group 2 in 43% of patients the level of anti-A-PSC IgM was above normal more than 2 times and in most cases in uncomplicated variants of disease course. In 45% of patients with severe form of soft tissue infection this parameter did not exceed normal values (p<0.05). CONCLUSION. In acute period of disease with simultaneous determination of ASL-O and IgM against A-PSC sensitivity of serologic diagnostics of SGA etiology angina and SGA infection of soft tissues was established to reach 92% and 72%, respectively, and humoral immune response to cellular AG in each form of SGA has its features.

Acute pharyngitis and tonsillitis are one of the most freguent illnesses. Most of episodes of the sore throat are coused by viral agents.Groupe A beta - hemolitic streptococcus still dominantes emong bacterial pathogens in upper respiratory tract infections and their late sequelae like rheumatic ferer determines the necessity of intensive therapy. Diagnosis should be made basing on results of clinical manifestations in conjunction with microbiological and serological tests. An inereased serum antibody titers to streptolisin O (antistreptolisin O -ASO) is usually indicative of recent streptococcal infection not active rheumatic fever.

Isolated bilateral striatal necrosis is an abnormality of the basal ganglia associated with acute dystonia in children. This report describes the development of dystonic movements in a 7-year-old male patient 2 weeks after streptococcal pharyngitis.

We report a 16-year-old patient who developed concurrent poststreptococcal reactive arthritis and acute glomerulonephritis. A high titer of antistreptolysin O antibody confirmed the preceding streptococcal infection. The patient presented with symmetric persistent tenosynovitis of hands and feet. Renal biopsy showed typical findings of acute glomerulonephritis with crescent formation. Physicians who treat patients with arthritis of acute onset, especially after throat infection, should be aware of possible urinary abnormalities or renal dysfunction.

Streptococcus pneumoniae is the most important cause of childhood pneumonia and empyema, yet the diagnosis of pneumococcal infections by conventional methods is challenging. In this study, the clinical value of the pneumolysin-targeted real-time polymerase chain reaction (PCR) method for the diagnosis of pneumococcal pneumonia and empyema was evaluated with 33 whole blood samples and 12 pleural fluid samples. The analytical sensitivity of the PCR assay was 4 fg of pneumococcal DNA, corresponding to two genome equivalents of pneumococcal DNA per reaction. The PCR assay correctly detected all clinical isolates of S. pneumoniae tested, whereas all nonpneumococcal bacterial organisms tested were negative by PCR. In a clinical trial, S. pneumoniae was detected by PCR in the pleural fluid of 75% of children with empyema, increasing the detection rate of pneumococcus almost tenfold that of pleural fluid culture. However, in whole blood samples, PCR detected S. pneumoniae in only one child with pneumonia and one child with pneumococcal empyema and failed to detect S. pneumoniae in three children with blood cultures positive for S. pneumoniae. The present data indicate that pneumolysin-targeted real-time PCR of pleural fluid is a valuable method for the etiologic diagnosis of pneumococcal empyema in children. The ease and rapidity of the LightCycler technology (Roche Diagnostics, Mannheim, Germany) make real-time PCR an applicable tool for routine diagnostics. In the evaluation of blood samples, blood culture remains the superior method for the diagnosis of bacteremic pneumococcal disease.

We have investigated the relationship between oxygen free radicals and acute rheumatic fever with regard to diagnosis of the disease process. At the time of diagnosis, we measured the levels of reactive oxygen molecules in the plasma, this being a parameter for oxygen free radicals, and discovered the levels to be significantly higher when compared with those measured in a control group (P<0.05). The levels measured in the plasma, however, were not statistically different among patients with and without carditis. We found a progressive decrease in the levels measured in the plasma when patients with acute rheumatic fever were tested on the 15th, 30th and 90th days subsequent to diagnosis. By the 90th day, levels measured in the plasma were still higher, but no longer significantly elevated, when compared with the control group. The present study is preliminary, but raises the possibility that measurement of oxygen free radicals in the plasma could be used as a laboratory test for active state of acute rheumatic fever. Further investigations will be needed, nonetheless, to determine the clinical application of this technique.

A chemiluminescent sandwich ELISA test has been developed for the detection and quantitation of pneumolysin. The test is based on a mouse monoclonal as the capture antibody and on rabbit polyclonal IgGs as detection antibodies, in combination with an anti-rabbit IgG alkaline phosphatase conjugate. The estimated detection limit of the purified recombinant toxin in phosphate-buffered saline with 0.05% Triton X-100 is around 5 pg ml(-1), with averaged intra- and inter-assay variation coefficients of 7% and 13.5%, respectively. The assay has been applied to the quantitation of pneumolysin in pneumococcal isolates, providing, for the first time, a direct measurement of the amount of the toxin produced by different strains, a variation has been found in their pneumolysin content. The test is highly specific as no other purified toxins or human pneumonia- or meningitis-associated bacteria yielded false-positive results. This specific and highly sensitive method could help in the diagnosis of human infections.

Background: The decline in infections in childhood may contribute to the rising severity and prevalence of atopic disorders in developed countries. Support for this hypothesis has been obtained from findings of an inverse association between tuberculin responses and atopy and from findings of high prevalence of asthma in certain islands with low prevalence of respiratory infections. With this regard, we investigated the association between serum anti-streptolysin-O (ASO) titers and the frequency of exacerbations of asthma in childhood., Methods: Thirty atopic asthmatic children who has no sign of upper respiratory tract infection at the time of presentation or during the previous two months were included in the study. Serum ASO titer was measured as an indicator of past streptococcal upper respiratory tract infections. ASO titer > or = 200 Todd units was accepted as positive., Results: A statistically significant association is found between high anti-streptolysin-O titers and decreased number of exacerbations in those children., Conclusions: Our data suggests that streptococcal infections might be a factor attenuating asthma in childhood.

Plasmodium falciparum is an intracellular parasite of human red blood cells (RBCs). Like many other intracellular parasites, P. falciparum resides and develops within a parasitophorous vacuole which is bound by a membrane that separates the host cell cytoplasm from the parasite surface. Some parasite proteins are secreted into the vacuolar space and others are secreted, by an as yet poorly defined pathway, into the RBC cytosol. The transport of proteins from the parasite has been followed mainly using morphological methods. In search of an experimental system that would allow (i) dissection of the individual steps involved in transport from the parasite surface into the RBC cytosol, and (ii) an assessment of the molecular requirements for the process at the erythrocytic side of the vacuolar membrane, we permeabilized infected RBCs with the pore-forming protein streptolysin O using conditions which left the vacuole intact. The distribution of two parasite proteins which served as markers for the vacuolar space and the RBC cytosol respectively was analysed morphologically and biochemically. In permeabilized RBCs the two marker proteins were sorted to the same compartments as in intact RBCs. The protein which was destined for the RBC cytosol traversed the vacuolar space before it was translocated across the vacuolar membrane. Protein transport could be arrested in the vacuole by removing the RBC cytosol. Translocation across the vacuolar membrane required ATP and a protein source at the erythrocytic face of the membrane, but it was independent of the intracellular ionic milieu of the RBC.

Streptococcal throat infection is a sine qua non for the development of rheumatic fever (RF) in genetically susceptible people. Demonstration of such infection is not easy. In overt RF less than 10% of patients still carry streptococci in their throat and immunologic methods are required to identify antibodies against streptococcal products (SP). Humoral response against SP was studied in children and adults with and without RF. Antistreptolysin O (ASO) showed a non-gaussian distribution, and reference value was established as percentile. Adults have a 97 percentile of 227, in children 90 percentile was 451. When RF was present all cases, except one, showed higher values. When antibodies against SP besides ASO were sought by an agglutination test (Streptozyme tm), people below 15 years of age showed low titers in 15 out of 28 cases. In contrast, high titers were the rule in children suffering RF. High ASO titer correlated with high Streptozyme value. These methods are capable to recognize an specific immune response against Group A Beta hemolytic streptococci, and are valuable tools in the diagnosis of RF.

We report on 4 patients with rheumatic fever hospitalized and investigated in our clinics within a 12 month period between 1990 and 1991. In each case a clinically non-severe sore throat preceded the outbreak of rheumatic fever. In three cases diagnosis was according to the revised Jones criteria. Polyarthritis was the only major symptom in these cases. One patient suffered from monarthritis. Minor symptoms were fever, arthralgia, elevated blood sedimentation rates and elevated values for CRP and for antistreptolysin O. The joint symptoms were treated with nonsteroidal drugs and subsided. One of the patients had a recurrence 9 months after the first attack even though correct secondary prophylaxis with a 4-weekly intramuscular regimen of 1.2 million units of benzathine penicillin was carried out. We discuss some epidemiological aspects and diagnostic difficulties resulting from a changing clinical pattern of the disease, and emphasize the need for streptococcal sore throat treatment and continuous secondary prophylaxis to prevent recurrences.

We developed an automated colorimetric assay based on liposome lysis for measurement of the titer of anti-streptolysin O antibodies (ASO) in human sera by using liposomes in which alkaline phosphatase (EC 3.1.3.1) was entrapped. The assay involved the inhibition by ASO of liposome lysis caused by streptolysin O. The procedure was fully automated for use with a routine clinical automated analyzer. The inter- and intra-assay precision showed that results were reproducible. Potential interfering substances such as bilirubin, hemoglobin, and triglycerides did not affect the results. With this assay, results correlated well with those by the Rantz-Randall method and the latex agglutination method (r = 0.900 and 0.890, respectively). This automated colorimetric assay for ASO should be of use for diagnosing streptococcal infections.

Authors review the most common laboratory tests showing an immunologic response caused by group A beta-hemolytic streptococcus infections. After a preliminary evaluation on characteristics and peculiarities of different methods the results obtained are compared with the usually employed systems. The survey of most common analytical methods and personal experience lead to confirm and emphasize the laboratory results supporting and confirming, without substituting, the clinical data.