The histological spectrum of tubulo-reticular inclusion positive renal biopsies: a tertiary hospital experience and review of the literature

ABSTRACTAim: To identify the underlying diseases with TRI-positive kidney biopsies, and describe the histological pattern and spectrum of TRI-positive kidney biopsies.Methods: A retrospective analysis of all patients’ chart that underwent renal biopsy at King Saud University Medical City between 2012 and 2017 was done. Kidney biopsies that indicated a positive result for tubuloreticular inclusions (TRI’s) on electron microscopy were reviewed and the underlying disease and histological pattern was extracted.Results: Of 1,473 native kidney biopsies reviewed, 96 (6.5%) were TRI-positive. Of the 96 TRI-positive kidney biopsies, 87 (90.6%) were TRI-positive lupus nephritis (LN); of which 10 (11.5%) were Class V, 49 (56.3%) were active LN, and 28 (32.2%) were inactive LN. The underlying diseases of the nine non-LN TRI-positive cases included diabetic nephropathy, connective tissue disorders, immune complex mediated Glomerulonephritis (GN), acute thrombotic microangiopathy, rhabdomyolysis, and Wegener’s disease....