Introduction:
Lupus nephritis (LN) is one of the most frequent and severe manifestation in patients with systemic lupus erythematosus (SLE). It is an immune complex glomerulonephritis usually manifested by proteinuria, hematuria, hypertension, and renal failure.
Systemic lupus erythematosus (SLE) is defined by clinical and laboratory features. The peak incidence of lupus is between 15 and 45 years with women out numbering men with a ratio of 8 to 15:1. LN affects both sexes equally and it is more severe in children and men. Approximately 25 to 50% of lupus patients will have clinical renal disease at onset while as many as 60% of adults with SLE will develop renal disease during their natural course. Kidney involvement may be suspected based on clinical symptoms, and laboratory markers but renal biopsy is essential for confirmation of lupus nephritis. It is required to determine the extent of disease activity, sub-classification, prognosis, and management.
LN is currently classified into 5 subclasses by the International Society of Nephrology (ISN) / Renal Pathology Society Classification (RPS) which is based on glomerular histology using light microscopy and direct immunofluorescence (IF) study. This is a retrospective study conducted in the tertiary care center. The objective of this study is to study the clinical and histopathological profile of (LN) lupus nephritis and its correlation with proteinuria.
Methods:
This is a hospital-based record study. We retrospectively studied patients with lupus nephritis in tertiary care center in central India from 2020-2024. Diagnosis of SLE was made based on the European Alliance of Associations for Rheumatology criteria (EULAR). All the diagnosed patients of SLE with proteinuria (Urine protein creatinine ratio >0.5) underwent Renal biopsy after written informed consent. Tissue was analyzed for histological type and direct immunofluorescence study. Data was entered in a Microsoft excel sheet and percentage, mean, and standard deviation were calculated.
Results:
The total number of patients included in the study was 120 of which 113 were female and 7 were male. The majority of the patients were in the age group 13-40 years. The age and gender distribution of the patients are shown in Tables 1 and 2.
Table 1 : Age wise distribution of study subjects
Table 2 : Genderwise distribution of study subjects
The most common presenting feature was pedal edema in 81.7% of the patients. Regarding other presenting features, joint pain was found in 79.2%, fever in 39.8%, serositis in 28.3%, malar rash in 24.2%, photosensitivity in 22.5%, oral ulcer in 21.6% and neuropsychiatric features in 5%. Hypertension was present in 39.2% of patients. Microscopic hematuria was present in 42.5%, and renal dysfunction in 20.8% of patients. Significant proteinuria was present in all patients. Among studied patients, Anemia was present in 90.8%, thrombocytopenia was present in 42.5% of patients, and leucopenia in 35% of patients. The presenting clinical and laboratory features are shown in Tables 3 and 4.
The antinuclear antibody(ANA) by immunofluroscence assay was positive(1:80) in all patients and serum complement (C3) levels were low in 45% of patients as shown in Table 4.
Table 3 : Clinical & Labortory Parameters of the patients
Table: 4 Anti –nuclear antibody and C3 status in the patients
On renal biopsy, the most common class found was class IV in 36.7% of patients followed by class IV+V in 16.7%, class II in 14.2%, class V in 9.9%, class III in 9.2%, class III+V in 5.8%, class I 3.3%, class II+V in 1.7%. Nonproliferative glomerulonephritis was found in 1.3% of patients. Full house pattern on immunofluorescence was present in all cases. The distribution of renal biopsy findings is shown in Table 5.
Table 5: Distribution of Class of Lupus nephritis in the study patients
Although significant proteinuria was found in all studied patients, maximum proteinuria was associated with class IV lupus nephritis and class IV +V.
The amount of proteinuria in different classes of LN was studied as shown in table 6.
Table 6: Amount of Proteinuria in different classes of lupus nephritis
Conclusions:
Lupus Nephritis is an important cause of morbidity in SLE patients. In Asian Populations incidence of lupus Nephritis is about 40 to 80%. In our study, the most common presenting feature was pedal edema. The majority of the patients had class IV lupus nephritis in this study. We also found the combination of the classes on renal biopsy of which IV + V LN had been commonly encountered in our study. It has been reported in 16.7% of cases with LN. We observed 4 patients with non-proliferative glomerular morphology on renal biopsy with significant proteinuria which can be explained either by tubulointerstitial involvement or lupus podocytopathy. Electron microscopic study is required to diagnose lupus podocytopathy, but due to limited resource availability, it could not be done. It is essential to thoroughly investigate the patients of SLE with significant proteinuria (UPCR >0.5). Proliferative lupus if not detected early leads to poor outcomes in terms of patients and renal survival. Hence, it is essential to evaluate SLE patients for kidney involvement for better outcomes.
I have no potential conflict of interest to disclose.
I did not use generative AI and AI-assisted technologies in the writing process.