Anti-streptolysin O Antibody Research Articles

B-048 Performance Evaluation of the New Anti-Streptolysin-O Assay on Mindray BS-2800M System

Abstract Background Elevated serum concentrations of Anti- Streptolysin-O(ASO) can be used to provide serologic evidence of past or present infection by β-Hemolytic Streptococci. Increasing serum concentrations of ASO antibodies are produced in response to ASO exotoxins secreted by the bacteria. Measurement of ASO antibody levels in serum can be used as an aid in the diagnosis of diseases such as glomerulonephritis, rheumatic fever, bacterial endocarditis, tonsillitis, and scarlet fever, etc. The New ASO assay has been evaluated on Mindray BS-2800M that is an automated, high throughput, and low cross-contamination system. The evaluation of this assay included precision, linearity, dilution accuracy, interference, high dose hook, and method comparison studies. Methods The new ASO reagent contains R1 buffer and R2 with latex particles conjugated with in-house made ASO antigen. The R1 is incubated with human serum sample containing ASO antibodies for 5 min at 37°C and then R2 is added. After another 5 min of incubation, immune-aggregation complex is formed. The increased turbidity is measured at 570 nm. By constructing a six-level calibration curve (water is used as reagent blank) from the absorbances of calibrators, the ASO antibody concentration of the sample is determined. Results The precision study was run according to EP05A3 with two commercial controls (approximately 80 and 300 IU/mL) and two serum sample pools (approximately 150 and 400 IU/mL) on the Mindray BS-2800M system. The repeatability and within-lab CVs ranged from 0.8% to 2.0% and 2.0% to 6.0%, respectively. The analytical linearity of the assay was determined as from 20 IU/mL to 1000 IU/mL with the limit of blank of 2 IU/mL and limit of detection of 10 IU/mL. The dilution accuracy was evaluated by diluting high ASO level samples at upper region of assay range using saline with 5-fold and run neat and diluted samples. The deviation in recoveries between diluted sample after calculation and the neat sample was found to be less than ±10%. The new ASO assay showed <±10% interference with bilirubin (conjugated or free) up to 40 mg/dL,hemolysate hemoglobin up to 1000 mg/dL,Intralipid up to 1000 mg/dL,and Triglycerides up to1000 mg/dL. The assay on the Mindray BS-2800M system(y) correlated well with the ASO assay(x) on the Beckman AU5800 system:y = 1.01 x + 1.55(r = 0.9514,n = 95,range:50–971 IU/mL). No prozone was observed with the assay on the Mindray BS-2800M system up to the highest ASO antibody concentration of 5000 IU/mL. Conclusion We conclude that the New ASO assay with in-house developed ASO antigen raw material, when used on the Mindray BS-2800M system, can measure serum ASO antibody concentrations precisely and accurately over a broad range. It is suitable for use in routine clinical laboratories.

Frequency of Familial Mediterranean Fever Gene Mutation in Patients Presenting With Joint Pain and Diagnosed With Acute Rheumatic Fever.

Introduction Acute rheumatic fever (ARF) is a non-suppurative systemic inflammatory disease that manifests 1-5 weeks following a Group A beta-hemolytic streptococcal infection. On the other hand, familial Mediterranean fever (FMF) is a hereditary autoinflammatory disease characterized as an autosomal recessive disease, with affected individuals having pathogenic mutations in the Mediterranean fever gene(MEFV)gene located on the short arm of chromosome 16. FMF and ARF have overlapping symptoms and signs, and both disorders are common in Turkey. In ARF, the target organ is the heart, while in FMF, the target organ is the kidney; both organs can benefit from prophylactic measures. Our study aims to determine the frequency of the FMF gene mutation in patients with ARF in Turkey and detect any overlapping conditions. Method Patients who were diagnosed with a first-attack ARF between May 2015 and May 2018 were retrospectively screened. Patients who underwent MEFV gene analysis considering FMF in the differential diagnosis were included in the study. Results In this study, no statistical difference was found between the presence of MEFV gene mutations, carditis, high anti-streptolysin-O antibody (ASO) levels, and the groups with monoarthritis, polyarthritis, and polyarthralgia (p >0.05). Conclusions In conclusion, patients with ARF should be evaluated for FMF to avoid irreversible complications.

Detection and analysis on serum antibodies for five common pathogenic microbes in patients with Posner-Schlossmarm syndrome

Background Posner-Schlossman syndrome (PSS) is often recurrent and is a cause of blindness.The etiology of PSS remains to be elucidated.It is reported that there is a certain association between pathogenic microorganisms and PSS in rather small samples. Objective This study was to analyze the related serum antibody levels of cytomegalovirus (CMV), herpes simplex virus (HSV), rubella virus (RV), helicobacter pylori (HP) and anti-streptolysin O (ASO) and provide a clue for the study on pathogenesis and therapy of PSS. Methods A prospective cases-controlled study was carried out in Shenzhen Eye Hospital from December, 2014 to December, 2016 under the approval of Ethic Committee of this hospital and informed consent of each subject prior to initial of any medical examination.Peripheral blood samples were collected from 82 PSS patients as the PSS group and 100 age-and gender-matched healthy blood donors as the normal control group.The positive rates of serum CMV IgG, CMV IgM, HSV IgG, HSV IgM, RV IgG, RV IgM, HP IgG and HP IgM in the subjects were detected by indirect ELISA, and the positive rate of serum ASO antibody was determined by immuno-scatter turbidmetry. Results The positive rates of serum CMV-IgG, CMV-IgM, HP-IgG, HP-IgM and ASO antibody were 22.0%, 17.1%, 22.0%, 17.1% and 17.1% in the PSS group, which were significantly higher than 5.0%, 0.0%, 10.0%, 2.0% and 7.0% in the normal control group (χ2=11.726, 18.496, 4.943, 12.766, 4.479, all at P 0.05). Conclusions CMV, HP and hemolytic streptococcal infection may participate in the occurrence and development of PSS. Key words: Posner-Schlossman syndrome; Etiology; Cytomegalovirus; Herpes simplex virus; Rubella virus; Helicobacter pylori; Anti-streptolysin O; Antibody

Clinical value of antistreptolysin O levels in adult patients with tonsillitis: report I.

To assess the clinical value of antistreptolysin O (ASO) level in adult patients with acute tonsillitis of group A beta-hemolytic streptococcus (GABHS) etiology and its interaction with the Centor score and throat cultures data. ASO antibody titers and throat cultures were obtained from 260 adult patients with acute tonsillitis of GABHS etiology initially proven by the Centor score. The results were compared with the group of 100 adult patients with recurrent tonsillitis who underwent tonsillectomy and with the group of 100 healthy adults. Throat cultures revealed GABHS-positive results in 69 acute cases (26.5%) and in 24 recurrent cases (24%), i.e., with no significant differences between the groups (p=0.845). There was no significant difference between cases with GABHS-positive and with GABHS-negative throat culture in ASO titers results (mean 250 and 280, respectively, p=0.44) but these titers were significantly higher than established normative data (p<0.01). For the group of recurrent tonsillitis cases, the mean ASO titer was 363 being significantly higher in comparison with acute cases (p=0.015). The ASO antibody titers are significantly higher than normative ranges in cases of acute tonsillitis in adults. The detection of the elevated titers may lead to early antibiotherapy to tonsillitis. The Centor score is supported by the ASO data and less supported by throat cultures data. Further research should reveal if these titers might have predictive value for possible further recurrence or serve as an indicator for tonsillectomy in cases of recurrent tonsillitis.

A case of rheumatic fever complicating carditis detected by a newly-developed systolic murmur in an adult woman

A 62-year-old woman presented to a primary care doctor on January 2006 due to a sore throat and high fever, and had received medication for a common cold. She was referred to our hospital in February 2006 because of additional manifestations such as painful rashes on the lower limb similar to erythema nodosum and polyarthralgia on her feet, shoulder and finger joints. She was initially treated with an anti-inflammatory drug (NSAID) for polyarthritis but the symptoms did not improved. In addition, the serum level of anti-streptolysin O antibody (ASO) was elevated at the second visit more than that at the first visit. She was diagnosed to have rheumatic fever (RF) based on the polyarthritis, inflammatory data and an increase of the ASO level. She was treated with 10 mg a day of prednisolone (PSL) and sultamicillin tosilate. However, a systolic murmur that had been never noticed by previous auscultation appeared after the third hospital day and the mitral regurgitation was also detected on echocardiogram. She was then treated with 40 mg a day of PSL because of an appearance of the carditis due to RF. The increased PSL dose promptly improved the systolic murmur as well as the arthritis. This report presented an RF case with carditis detected by an development of the systolic murmur in an adult female.

THE CLINICAL-DIAGNOSTIC ROLE OF ANTISTREPTOLYSIN O ANTIBODIES

The antistreptolysin O antibody (ASLO) test is often requested in a clinical setting with limited evidence for its usefulness. For this reason, the diagnostic scenario in which ASLO plays an evidence-based role and the analytical performance of the test are critically appraised, taking into account the clinical need and the direct medical cost. Little or no scientific evidence was found for the use of ASLO in patients with pharyngitis, post-streptococcal glomerulonephritis and in adults with rheumatoid arthritis. The clinical relevance of ASLO is restricted to paediatrics, where it contributes to fulfil the diagnosis of acute rheumatic fever (ARF) as per Jones criteria. The standardization of current automated ASLO-latex assays is limited. Attention should be paid to inaccurate reference values and many circumstances causing false positive and false negative results. Because of a low prevalence of ARF in the Western world, a high negative predictive value is obtained for the ASLO test (> 99%). In clinical practice, the result of the test is not urgent. To reduce overconsumption, the clinical laboratory should drive the request behaviour of physicians by a strategic lay-out of the application form. The health insurance/government also contributed by introducing a diagnostic rule for reimbursement.

HLA and T cell receptor associations in narcolepsy, a disorder associated with the selective loss of hypocretin neurons (47.17)

Abstract Narcolepsy is a life long disorder characterized by severe sleepiness and cataplexy. It affects 1 in 2,000 individuals and is caused by the selective loss of the hypocretin producing neurons in hypothalamus. This cell loss is likely to be autoimmune and recent findings are closing in on some of the key genetic and environmental effects involved. At the genetic level, the disorder is very tightly associated with DQA1*01:02/DQB1*06:02. In addition to the established role of HLA-DQ, a specific T Cell Receptor Alpha J segment polymorphism has been identified as another susceptibility factor. We are currently sequencing the T-cell TCR@ repertoire to explore this further in recent onset narcolepsy cases. At the level of environmental triggers, winter related upper airway infections are believed to be involved, e.g. we have reported an increased presence of antistreptolysin-O antibody, implicating a role for streptococcal infections. In China, studies of disease onset seasonality indicate a 16 fold increase in onset occurrence around spring when compared to early winter. We anticipate that the cause of narcolepsy will likely involve a specific antigen presentation by DQA1*01:02/DQB1*06:02 to a restricted number of pathogenic T-cell subtypes. As immune involvement is increasingly being recognized in neurodegenerative and neuropsychiatric disorders, understanding why the hypocretin neurons in narcolepsy die is likely to increase understanding of these other disorders as well.

Anti-Tribbles Homolog 2 (TRIB2) Autoantibodies in Narcolepsy are Associated with Recent Onset of Cataplexy

Recent studies have found increased autoantibodies against Tribbles homolog 2 (anti-TRIB2) and anti-streptolysin O (ASO) in narcolepsy. In this study, we replicated this finding with a primary focus on recent onset cases. Participants included (1) 90 cases with cataplexy, (2) 57 cases without cataplexy, and (3) 156 age-sex matched controls, including 73 human leukocyte antigen (HLA)-DQB1*0602 allele carriers. A radioligand binding assay was used to detect anti-TRIB2 antibodies. Anti-TRIB2 antibodies were prevalent in HLA-DQB1*0602 positive cases with cataplexy (25.0% of 76) and rare in cases without cataplexy (3.5% of 57, OR = 9.2, 95% CI = 2.5 - 33.5, P = 6.0 x 10(-4)) or controls (4.5% of 156, OR = 7.1, 95% CI = 3.1 - 16.2, P = 9.3 x 10(-6)). Anti-TRIB2 positivity in controls was not associated with DQB1*0602. In DQB1*0602 narcolepsy-cataplexy cases, the presence of anti-TRIB2 was associated with short disease duration (2.3 years from cataplexy onset), with 41.0% positive in this group (OR = 7.4 versus cases with onset > 2.3 years, 95% CI = 1.9- 28.5, P = 9.0 x 10(-4)). Anti-TRIB2 positivity in 39 DQB1*0602 positive recent onset cases was associated with increased ASO antibody (> 200 IU) (OR = 6.2, 95% CI = 1.6 - 24.6, P = 0.01), but did not correlate with age, gender, or body mass index. Anti-TRIB2 autoantibodies are strongly associated with narcolepsy close to cataplexy onset (< or = 2.3 years). Anti-TRIB2 was rarely found in cases without cataplexy or with distant onset.

Serodiagnosis of listeriosis based upon detection of antibodies against recombinant truncated forms of listeriolysin O

Amino-terminal fragments of listeriolysin O (LLO) of 240 and 411 residues (fragments LLO240 and LLO411, respectively) were expressed in Escherichia coli as fusion polypeptides with maltose-binding protein (MBP) with the aim of producing specific antigens for use in serological tests. In Western blots (immunoblots) with crude bacterial extracts of the fusion polypeptides, the reactivities of MBP-LLO240 and MBP-LLO411 with anti-LLO antibody (ALLO)- and anti-streptolysin O antibody (ASLO)-positive human sera were first compared with that of the entire LLO (LLO530) also fused to MBP (MBP-LLO530). Sixteen of 17 (94.1%) ALLO-positive samples reacting with MBP-LLO530 also reacted with MBP-LLO411, whereas this proportion dropped to 11 of 17 (64.7%) with MBP-LLO240. Alternatively, 18 of 19 (94.7%) ASLO-positive samples giving an interpretable result reacted with MBP-LLO530, whereas 1 of 19 (5.3%) of these samples reacted with MBP-LLO240 or MBP-LLO411. The fusion polypeptide MBP-LLO411 was purified by maltose affinity chromatography and was further evaluated as a diagnostic antigen in a Western blot assay. Twenty-one of 21 (100%) serum samples obtained from patients with listeriosis and found to be positive for ALLO by a reference dot blot test reacted with MBP-LLO411, whereas 1 of 20 (5%) ASLO-positive serum samples and 1 of 100 (1%) serum samples from healthy adults were reactive. Thus, a polypeptide limited to the 411 amino-terminal residues of LLO is a specific and sensitive antigen for the detection of ALLO.

Serum anti‐streptococcal IgA, IgG and IgM antibodies in IgA‐associated diseases

Serum anti-streptolysin-O antibody (ASO) and anti-streptococcal polysaccharide antibody (ASP) of IgA, IgG and IgM classes were measured using an enzyme-linked immunosorbent assay in 41 children with IgA nephropathy (Group A), 15 children with uncomplicated anaphylactoid purpura (Group B) and 13 children with purpura nephritis (Group C). The serum concentrations of the IgA, IgG and IgM classes were measured by single radial immunodiffusion. When compared with sex- and age-matched controls, the concentrations of serum IgA (but not of IgG or IgM) were significantly increased in the three groups studied. The titers of ASO of the IgA and IgM classes, and those of ASP of the IgA and IgG classes, were significantly increased in Group A. In Group B, only the ASP titers of the IgA class were significantly increased. No significant difference was noted in the titers of either ASO or ASP of any class in Group C. Thus, increased antibody response in IgA nephropathy is not restricted to IgA. Anaphylactoid purpura with or without renal disease appears to be different in its humoral anti-streptococcal response from IgA nephropathy.

Antideoxyribonuclease B titers in psoriasis

Psoriatic patients were examined for serologic evidence of streptococcal infections by using antideoxyribonuclease B (ADB), which has been shown to be a more sensitive screening tool than antistreptolysin O (ASO) for detecting such evidence in other clinical circumstances. Antistreptococcal antibody titers (ASO and ADB) of 71 patients with psoriasis vulgaris, 7 with guttate psoriasis, and 6 with erythrodermic psoriasis were compared with ASO and ADB antibody titers of 25 non-psoriatic dermatologic patients hospitalized at the same time and of an adult group that was used as a control for the test itself. Thirty-six of 71 patients with psoriasis vulgaris had elevated titers of ADB or ASO (41% vs. 15%). Compared with control values the ADB titers were significantly higher in patients with psoriasis vulgaris (P less than 0.02) and patients with guttate psoriasis (P less than 0.05). The ASO titers were significantly higher in patients with psoriasis vulgaris than in controls (P less than 0.04). Within the group with psoriasis vulgaris, ADB titers were significantly higher than ASO titers (P less than 0.01). Among patients with psoriasis vulgaris, histories of sudden flares of psoriasis and early recurrences of psoriasis after previous successful hospital treatment, family histories of psoriasis, and histories of potential streptococcal infections were more frequent in those with elevated antistreptococcal antibodies.

An immunoglobulin G myeloma with antistreptolysin activity and a lifelong history of cutaneous streptococcal infection

A case of an IgG myeloma producing antistreptolysin-O (AST-O) antibody in a 68-year-old male patient is presented. During all of his life the patient has had a factitious dermatitis on the hands and face. Fifteen years ago, an AST-O titer of 6400 IU/ml was observed and considered to be due to a streptococcal infection of the skin lesions; the erythrocyte sedimentation rate (E.S.R.) was normal. In 1965, the AST-O had risen to 25,600, but the E.S.R. remained normal. In the autumn of 1975, the patient developed lower back pains, the E.S.R. rose rapidly to 78 mm/hr, the AST-O titer was 51,200, and IgG myeloma was diagnosed. Monoclonal IgG isolated from the serum had AST-O activity of 1400 IU/mg residing exclusively in the Fab fraction, and production of AST-O by bone marrow cells was demonstrated by tissue culture. The role of antigenic stimulation in the pathogenesis of myeloma is discussed.

The effect of beta-lipoprotein on antistreptolysin-O antibody titers.

ABSTRACTThe relationship between antistreptolysin‐O (ASLO) titers and β‐lipoprotein were examined. The following results were obtained. 1. Fifty‐three children with unmeasurably low ASLO titers had variable β‐lipoprotein concentrations which were within normal ranges. 2. Streptococcal infections in the children correlated well with the elevation of ASLO titers, but β‐lipoprotein concentration in these sera did not show any correlation with the behavior of ASLO titers. 3. From the Sephadex G‐200 gel filtration chromatographical study, no ASLO activities were found in the fraction containing β‐lipoprotein except in some special cases that had the IgM ASLO antibody. 4. The inhibitory effect of β‐lipoprotein upon hemolysis by streptolysin‐O was incomplete and its effect decreased with a prolonged incubation time. 5. The partially purified β‐lipoprotein had no effect upon the hemolytic activity of streptolysin‐O, when the ASLO titers were measured by the method of 100% inhibition of hemolysis. From these observations, it was concluded that the ASLO antibody titers were truly related to streptococcal infection and not influenced by the presence of β‐lipoprotein if the ASLO titers were measured by the 100% inhibition of hemolysis.