[Antibodies to myocardial muscle fiber sarcolemmic antigens in rheumatism and other heart diseases]. / Izuchenie antitel k asntigenam sarkolemmy myshechnogo volokna miokarda pri revmatizme i drugikh zabolevaniiakh serdtsa.

The work discusses the results of studying by indirect immunofluorescence and the passive hemagglutination test antibodies to sacolemma antigens of myocardial muscle fiber in patients with rheumatic fever as compared to those in patients with affection of myocardium of nonrheumatic origin. The frequency of the detection of antibodies to sarcolemma antigens in sera of patients with rheumatic fever by immunofluorescence correlates with the activity of the process. No differences were revealed in the frequency of detection of antibodies reacting with sarcolemma in rheumatic fever and in other heart diseases in the active phase. Antibodies to sarcolemma antigens contained in HCL-extracts from human myocardium preparations, which are detected in the passive hemagglutination test are revealed significantly more often in sera of patients with rheumatic fever. Control experiments with IgG fractions obtained from whole sera were conducted to remove any possible nonspesific reactions of tissue extracts with the sera tested.

[Ordering of antibodies, that react with cardiac muscle fiber and interstitial connective tissue antigens, in different immunoglobulin classes]. / Prinadlezhnost' antitel, reagiruiushchikh s antigenami myshechnogo volokna i interstitsial'noi soedinitel'noi tkani serdtsa k raznym klassam immunoglobinov.

Sera of patients suffering from rheumatic diseases and myocarditis were examined on the sections of human and bovine myocardial tissue by indirect immunofluorescence with the use of pure IgG antibodies or monospecific sera against IgG, IgA and IgM. It was shown that antibodies reacting with different myofibers and interstitial connective tissue of the heart belong to the main immunoglobulin classes (IgG, IgA and IgM). There was a significant predominance of IgG antibodies as shown by the frequency of their detection and by the titer height. The predominance of antibodies to certain classes of immunoglobulins did not correlate with a specific disease entity. The frequency of detecting antibodies to a certain immunoglobulin class was in good agreement with the time of the disease onset. Moreover, the frequency of positive reactions due to IgG, IgA, and IgM antibodies correlated with the level of the appropriate immunoglobulins in the test sera.

[Reactions of normal human and rabbit immunoglobulins with heart valve fibroblasts]. / Reaktsii normal'nykh immunoglobulinov cheloveka i krolika s fibroblastami klapanov serdtsa.

It was demonstrated using the indirect immunofluorescent technique that normal human and rabbit sera, and IgG isolated from them intensively reacted with fibroblasts of human and bovine heart valves. The results obtained with Fab and Fc fragments of IgG sugges that this reaction is due to the Fc region of the IgG molecule and related to the presence of the Fc receptor on fibroblasts of heart valves.