<prompt> What is the mechanism of acute rheumatic lever -Cross reactivity with host antigenInnocent by slender effectDue to toxin secretion by streptococciRelease of pyrogenic cytokines  <response>: Rheumatic fever is an acute, immunologically mediated, multisystem inflammatory disease that occurs after group A b-hemolytic streptococcal infections usually pharyngitis, but also rarely with infections at other sites such as skin. Rheumatic hea disease is the cardiac manifestation of rheumatic fever. Acute rheumatic fever is a hypersensitivity reaction classically attributed to antibodies directed against group A streptococcal molecules that also are cross-reactive with host antigens. Robbins basic pathology,9th edition,pg no.391 