[Humoral immune response in patients with angina and soft tissue infections of group a streptococci etiology]

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.