Comparison of Histomorphological Indices Between Adult and Pediatric Patients in Response to Induction Therapy

Renal involvement, known as lupus nephritis (LN), is a common and serious complication of systemic lupus erythematosus (SLE), linked to significant morbidity and mortality. Histomorphological indices, such as the activity index (AI) and chronicity index (CI), are critical in predicting treatment responses and outcomes. This study aims to compare these histomorphological indices between adult and pediatric patients with LN and evaluate their impact on post-induction therapy outcomes.

A cross-sectional analysis was conducted at a single nephrology department from 2005 to 2019, including patients with biopsy-confirmed LN. Data on demographic characteristics, histomorphological indices, and clinical outcomes post-induction therapy were collected. Statistical analysis was performed using IBM SPSS Statistics for Windows, Version 20.0 (Released 2011; IBM Corp., Armonk, New York, United States) to identify significant correlations and differences.

Pediatric patients exhibited significantly lower AI (p=0.042) and CI scores compared to adults. Lower frequencies of hyaline thrombi (p=0.005) and tubular atrophy (p=0.028) were observed in the pediatric group. Key predictors of a complete response to induction therapy included interstitial inflammation <0.65 and tubular atrophy <0.63. Significant correlations were found between post-induction renal function tests (RFT) and indices such as AI (p=0.035), CI (p<0.001), cellular and fibrocellular crescents (p<0.001), and tubular atrophy (p<0.001). Proteinuria outcomes were significantly associated with CI (p=0.040), interstitial inflammation (p=0.006), and tubular atrophy (p=0.026).

The conclusion aligns with the established understanding that pediatric patients with LN often have a different disease trajectory compared to adults. Pediatric patients generally presented with less severe histomorphological damage, contributing to better responses to induction therapy. Detailed histopathological assessments are essential for guiding treatment strategies and improving patient prognosis in both adult and pediatric LN populations.