CD79A and thrombocytopenic purpura: Recently, several research groups have updated the diagnostic criteria for HSP [4], with palpable non-thrombocytopenic purpura (mandatory criterion) with lower limb predominance in the presence of at least one of the following four features: (1) abdominal pain, (2) histopathology showing typical leukocytoclastic vasculitis with predominant IgA deposition or proliferative glomerulonephritis with predominant IgA deposition, (3) arthritis (acute, any joint) or arthralgia, and (4) renal involvement: hematuria or proteinuria.