Evidence of follicular T-cell implication in a case of IgG4-related systemic disease with interstitial nephritis.

IgG4-related systemic disease is a protean disorder that covers a wide variety of lesions. We report on a patient with tubulointerstitial nephritis, lymphadenopathies, sialadenitis and retroperitoneal fibrosis. The salivary gland and kidney interstitium were infiltrated with B lymphocytes and T lymphocytes and IgG3(+) and IgG4(+) plasma cells.