Tubulo-reticular inclusions in lupus nephritis: are they relevant?

Tubulo-reticular inclusions (TRIs) are organized subcellular structures that may be found in endothelial cells of patients with systemic lupus erythematosus (SLE). This study was conducted to determine the presence or absence of TRIs and their correlation with the activity index (AI) and lupus nephritis (LN) class. A retrospective analysis of 57 cases of LN over a three-year period (2008-2011) was performed from medical records of the King Khalid University Hospital (KKUH), Riyadh. After reviewing and sorting them by class as per the International Society of Nephrology (ISN/RPS) 2004 classification of LN, the cases were divided according to the presence or absence of TRIs. The relationships between the presence or absence of TRIs and the AI were determined. Of the 57 kidney biopsies reviewed, 49 were proliferative cases (Class III and IV), of which 12 (24.5%) had TRIs. The mean AI was 6.01 ± 3.8 and the mean chronic index was 3.0 ± 1.5. Four (11.4%) class IV cases had a high AI, while no Class III cases with TRIs showed increased activity. The presence of TRIs was significantly associated with the AI (r = 9.40, P = 0.002), but not with LN class (r = 0.099, P = 0.753). Examining for TRIs in LN is still favorable and helpful in cases where the diagnosis of SLE is pending or not yet established, although the presence of TRIs is not a specific finding.