ANTI-CD45 STAINING IN RENAL HISTOPATHOLOGY AS A PREDICTOR OF CLINICAL PRESENTATION AND SHORT-TERM OUTCOME IN LUPUS NEPHRITIS

Introduction:

Systemic lupus erythematosus (SLE) commonly affects the kidney, when it is known as lupus nephritis (LN). Despite treatment, about 30% of LN patients progress to end stage renal disease (ESRD) within 10 years after the disease onset. Renal histopathology is the best way to detect and classify LN. With the current histopathological techniques and markers, assessing disease activity and predicting outcome is often difficult. Use of anti-CD45 staining in renal histopathology as a newer marker to assess tubulointerstitial involvement and predict clinical outcome independent of International Society of Nephrology / Renal Pathology Society (ISN/RPS) classification has shown promise in LN.

Methods:

This prospective observational study was conducted in the department of Nephrology, Bangabandhu Sheikh Mujib Medical University (BSMMU), Dhaka, from September 2021 to August 2022. Renal biopsy was performed on adult SLE patients diagnosed as LN admitted to the department who were enrolled in this study. Biopsy sample was handled by a single renal histopathologist. Anti-CD45 staining was used. The renal histology was classified according to the ISN/RPS 2003 LN classification. Clinical and biochemical parameters were noted at baseline. SLE Disease Activity Index (SLEDAI) was used to assess disease activity. Patients received treatment as per institutional protocol according to the Kidney Disease Improving Global Outcome (KDIGO) guideline. All the patients were followed-up at 2nd and 6th month following renal biopsy with clinical features and investigations.

Results:

A total of 45 LN patients were enrolled in this study. During the study period, two patients were lost to follow-up. The mean age of the lupus patients was 28.2 years. Most patients (86.7%) were female. Class IV LN was most frequently found. Higher anti-CD45 staining intensity was associated with higher SLEDAI score at presentation, 2-month and 6-month follow-ups (p=0.004, 0.01, 0.03). For every unit increase in anti-CD45 intensity, the SLEDAI score was 2.1 unit higher at baseline (p=0.001). Interstitial anti-CD45 deposition was associated with significantly higher tubulointerstitial involvement (p=0.03) (Mean TI in glomerular deposition was 19.7% and in interstitial deposition was 31.1%). Higher anti-CD45 intensity is associated with higher chronicity indices (p = 0.006). About 32.6% and 34.9% of the patients achieved complete and partial remission respectively, and 32.6% of patients had no remission at 6-month follow up. Higher anti-CD45 staining intensity was associated with more non-remissions and partial remissions (p=0.0001, <0.0001).

Conclusions:

Anti-CD45 is an essential marker of inflammation and is subject to less inter-person variability on renal histopathology. Including anti-CD45 staining deposition site and intensity on renal histopathological assessment and developing a more comprehensive chronicity index will assist clinicians in early recognition of severe LN more accurately and help predict the risk of developing severe disease and poor response to treatment.

I have no potential conflict of interest to disclose.

I did not use generative AI and AI-assisted technologies in the writing process.