"CLINICOPATHOLOGICAL CORRELATION OF HEMATOLOGIC ALTERATIONS AND TISSUE HISTOPATHOLOGY IN SYSTEMIC LUPUS ERYTHEMATOSUS

Background: Systemic Lupus Erythematosus (SLE) is a chronic autoimmune disorder characterized by the production of autoantibodies, immune complex deposition, and multisystem involvement. Hematological abnormalities are among the earliest and most frequent manifestations of the disease, often reflecting disease activity and severity. Understanding the relationship between peripheral hematologic alterations and underlying tissue pathology is essential for early diagnosis, prognostication, and therapeutic decision-making. Objectives: This study aims to evaluate the clinic pathological correlation between hematologic abnormalities and tissue histopathological changes in patients with SLE. It seeks to identify specific hematologic markers associated with particular histopathologic patterns and disease activity scores. Methodology: A prospective observational study was conducted over a period of 18 months at a tertiary care center. A total of 80 patients fulfilling the ACR/EULAR 2019 criteria for SLE were enrolled. Complete blood counts, peripheral blood smears, reticulocyte counts, and Coombs tests were performed for hematological evaluation. Bone marrow aspiration/biopsy was performed in selected cases with persistent cytopenias. Tissue biopsies (renal, skin, and lymph node) were obtained based on clinical indications. Histopathological findings were analyzed and correlated with hematologic parameters and SLE Disease Activity Index (SLEDAI) scores. Results: Out of 80 patients, 91.3% were female with a mean age of 29.4 ± 8.2 years. Anemia was observed in 82.5% of patients (normocytic normochromic in 42.5%, microcytic hypochromic in 25%, and hemolytic in 15%). Leukopenia was noted in 47.5% and thrombocytopenia in 36.2%. Direct Coombs test was positive in 22.5% of cases. Bone marrow studies revealed erythroid hyperplasia in hemolytic anemia, hypocellularity in aplastic presentations, and increased histiocytes in macrophage activation syndrome (MAS)-like features. Renal biopsies (performed in 35 patients) revealed class III and IV lupus nephritis in 71.4% of cases with accompanying hematologic abnormalities such as anemia and thrombocytopenia. Cutaneous biopsies showed interface dermatitis in 65% and leukocytoclastic vasculitis in 20%, correlating with leukopenia and raised ESR/CRP. Lymph node biopsies demonstrated reactive hyperplasia and, in some cases, necrotizing lymphadenitis suggestive of Kikuchi disease. Statistically significant correlations were found between anemia and lupus nephritis (p=0.03), leukopenia and skin involvement (p=0.04), and thrombocytopenia with disease activity scores >10 (p=0.01). Conclusion: Hematologic abnormalities in SLE are common and exhibit a significant correlation with underlying histopathological findings in various tissues. Anemia is strongly associated with lupus nephritis, while leukopenia often reflects cutaneous vasculitic changes. Thrombocytopenia serves as a potential marker of severe disease activity. Recognizing these correlations may aid in early diagnosis, disease monitoring, and guiding biopsy decisions in SLE management.