198 - Nonsuppurative Poststreptococcal Sequelae: Rheumatic Fever and Glomerulonephritis

Abstract

Nonsuppurative poststreptococcal sequelae include acute rheumatic fever (ARF) and acute glomerulonephritis (AGN). They develop subsequent to group A streptococcal (GAS) pharyngitis (ARF and AGN) or pyoderma (AGN). ARF particularly involves migratory polyarthritis and/or acute carditis manifested as mitral and/or aortic insufficiency. The pathogenesis of ARF likely involves molecular mimickery. AGN is mediated by antigen-antibody complex deposition accompanied by complement deposition. ARF occurs predominantly in patients age 5 to 15 years, most commonly in winter-spring, while postpharyngeal AGN occurs mainly in school-aged children in summer or fall. Certain M/emm-types of GAS are particularly rheumatogenic and some M/emm-types of GAS are nephritogenic, but the specific bases of these characteristics are not clear. ARF is diagnosed by applying the Jones Criteria (5 majors: carditis, polyarthritis, chorea, subcutaneous nodules, and erythema marginatum; 4 minors: elevated acute phase reactants, prolonged P-R interval on ECG, fever, and arthralgia) with a near-absolute requirement of microbiologic or serologic evidence of recent GAS infection. The only long-term sequela of ARF is chronic rheumatic heart disease, which is a very serious and common problem particularly in many low income countries. AGN presents with hematuria, hypertension, edema, and oliguria. Immunosuppressive therapy is not useful and patients are treated symptomatically with excellent outcomes, especially in children. ARF therapy includes long-term antibiotic prophylaxis to prevent subsequent GAS pharyngitis episodes with risk of recurrent ARF with increasingly severe heart disease.