It can be secondary to direct vascular insult or immunologically mediated and most frequently occurs in severe immunocompromised patients (CD4 count <200 cells/mL), associated with opportunistic infections (including hepatitis, HTLV-1, CMV, tuberculosis, parvovirus, syphilis) or in the absence of identifiable causes.9–11 In this case, the pathology reported a predominantly lymphocytic vasculitis of the mesenteric and intramural arteries, which are middle-sized vessels. The gene discussed is CD4; the disease is hepatitis A virus infection.