Table 2.
Renal pathologies diagnosed by immunofluorescence on paraffin embedded biopsies
| Diagnosis | Total number of cases | Number of cases with non diagnostic IF-P (%) | Remarks |
| MPGN | 32 | 21 (6.2%) | Classification into immune complex mediated MPGN ( 18 cases) and complement mediated MPGN ( 12 cases ) was possible 1In two cases C3 was not demonstrated and electron microscopy showed features of dense deposit disease |
| Membranous nephropathy | 11 | 21 (22.2%) | In one case staining intensity of IgG was only 1+, however staining pattern was classical 1In 2 cases significant fine granular immunofluorescence was not noted |
| Lupus nephritis | 25 | 11 (4%) | Classification into Class II ( 2 cases), Class III/IV ( 15 cases) and Class V (5 cases ) was possible Two cases of lupus podocytopathy were diagnosed 1In one case of lupus nephritis only IgM was demonstrated significantly, though electron dense deposits were noted on electron microscopy |
| Diffuse proliferative glomerulonephritis - post infectious glomerulonephritis | 12 | 11 (8.3%) | 1In one case only 1+ IgG and trace C3 deposition noted No tissue for electron microscopy was available |
| Pauciimmunecrescentic glomerulonephritis | 7 | - | - |
| IgAN | 39 | - | In 64 cases (minimal change morphology, mesangial proliferation or FSGS), IgAN was excluded by IF-P In one case of diabetic nephropathy IF-P was used to exclude secondary IgAN |
| C1q nephropathy | 2 | - | - |
| Light chain deposition disease | 1 | - | Tubular basement membrane and vascular deposits were also noted in addition to the glomerular deposits |
| Amyloidosis | 4 | - | 2 cases of AL amyloid (demonstrating light chain restriction) and 2 cases of AA amyloid |
| CGN | 8 | 3 (37.5%) | The immune complexes could not be demonstrated in 3 cases of chronic glomerulonephritis, one of these was a case of biopsy proven MPGN and the other was a case of IgAN. In one case of CGN no immune complexes were seen, however no previous renal biopsy record was available |
| Cast nephropathy | 2 | - | One case also demonstrated light chain restriction |
| Tubulointerstitial nephritis | 9 | - | Associated immune complex mediated glomerular disease was excluded |
1
Non diagnostic cases and details of their immunofluorescence pattern. MPGN: Membranoproliferative glomerulonephritis; CGN: Chronic glomerulonephritis; IgAN: IgA nephropathy; FSGS: Focal segmental glomerulosclerosis.