Clinicopathological spectrum of two common conditions encountered in renal biopsies: acute diffuse proliferative glomerulonephritis and lupus nephritis

Background: Acute diffuse proliferative glomerulonephritis (ADPGN) and lupus nephritis (LN) are commonly encountered conditions in renal biopsies. ADPGN is usually a self-limiting childhood disease occurring commonly after streptococcal infection. LN is a common complication of systemic lupus erythematosus (SLE) with diverse clinical and histological features.

 

Objectives: The objective of this study is to describe the clinico-pathological spectrum of ADPGN and LN in renal biopsies.

 

Method: A retrospective-descriptive study was done by retrieving all renal biopsies (1225) received in the year 2018 at the Department of Pathology, Faculty of Medicine, University of Peradeniya. Biopsies diagnosed as ADPGN and LN were selected.

 

Results: Out of all renal biopsies (1225), 63(5.1%) were diagnosed as ADPGN and 92(7.5%) as LN. ADPGN was seen in an age range of 3-78 years. 24(38.1%) were children and 39(61.9%) were adults. Nephritic syndrome (NS) was the commonest presentation in both children and adults (n=23,36.5%) while 13(20.6%) showed nephrotic-nephritic mixed picture (NNMP).

 

Cellular crescents were seen in 11 patients (17.4%) and most were adults with NNMP. Tubular injury was seen in 19 (30.1%) and most were children with NNMP. 34 (53.9%) patients showed classic uncomplicated ADPGN. Immunofluorescence showed IgG-positivity in 9(14.2%). C3 was positive in 27(42.8%).

 

In LN cases, 47(51.09%) patients were women with Class IV lesions, which was the commonest group. Of the class IV patients (n=56) most presented with non-nephrotic range proteinuria (NNRP), while 35 (62.5%) had microscopic haematuria (MH) and 26(46.4%) showed elevated serum creatinine. All class II patients(n=15) were women (100%). 9 (60%) patients showed NNRP, 9 (60%) MH and 4(26.7%) elevated SC. All class III patients(n=5) were also women who had NNRP and MH. SC was elevated in 1(20%) patient.

 

Conclusions: Most children and adults who underwent renal biopsy for ADPGN had presented with NS while a lesser number had NNMP. A study done by Wijewickrama et al. in 2015 also revealed that NS was the commonest presentation of ADPGN in adults. Common complications detected in our study were cellular crescents and tubular injury which were found more in patients with NNMP than NS. C3-positivity was commoner than IgG possibly because biopsies were performed during the latter phase of the disease. Common classes of LN were class IV, II and III. Most of these patients had NNRP and MH while a lesser number showed elevated serum creatinine.