Differentiation of patients with rheumatic fever from those with inactive rheumatic heart disease using the artificial subcutaneous nodule test, myocardial reactive antibodies, serum immunoglobulin and serum complement levels.
Thirty patients with acute rheumatic fever, and 20 with inactive rheumatic heart disease were studied in order to determine parameters which differentiate the two groups. Subcutaneous nodules developed following the subcutaneous injection of autologous blood in 16 of 26 patients with rheumatic fever but in none of the 20 with inactive rheumatic heart disease (P = 0.00001). Myocardial reactive antibodies were found in 14 of 30 patients with rheumatic fever, and in 4 of 20 with inactive rheumatic heart disease (P = 0.0505). Significantly higher values of IgG (P less than 0.001), IgA (P less than 0.01), C3 (P less than 0.001) and C4 (P less than 0.001) were observed in rheumatic fever patients. There was no significant difference in IgM levels. A combination of three variables (artificial subcutaneous nodules, IgA, and C3) had a sensitivity of 87% and a specificity of 100% for rheumatic fever. A combination of two variables (artificial subcutaneous nodules and IgA) had a sensitivity of 84% and a specificity of 100% for rheumatic fever.
D000293:Adolescent; D001323:Autoantibodies / Q000032:analysis; D002648:Child; D003176:Complement C3 / Q000032:analysis; D003181:Complement C4 / Q000032:analysis; D003165:Complement System Proteins / Q000032:analysis; D003937:Diagnosis, Differential; D006801:Humans; D007070:Immunoglobulin A / Q000032:analysis; D007074:Immunoglobulin G / Q000032:analysis; D007136:Immunoglobulins / Q000032:analysis; D009206:Myocardium / Q000276:immunology; D012213:Rheumatic Fever / Q000175:diagnosis* / Q000276:immunology; D012214:Rheumatic Heart Disease / Q000175:diagnosis* / Q000276:immunology
D001323:Autoantibodies; D003176:Complement C3; D003181:Complement C4; D007070:Immunoglobulin A; D007074:Immunoglobulin G; D007136:Immunoglobulins; D003165:Complement System Proteins