Tubulointerstitial Nephritis Cases With IgM-Positive Plasma Cells

Tubulointerstitial nephritis (TIN) is an inflammatory disorder in renal tubules and interstitium without involvement of glomerular lesions. Causes of TIN are diverse and include drug reactions, Sjögren syndrome, sarcoidosis, tubulointerstitial nephritis and uveitis (TINU) syndrome, and IgG4-related kidney disease, although the causes remain unknown in many cases, which are diagnosed as idiopathic TIN.1Saeki T. Nishi S. Imai N. et...