Significance of extracapillary proliferation in IgA-nephropathy patients with regard to clinical and histopathological variables.
OBJECTIVE
Extracapillary proliferation (crescent) was not included in the Oxford classification, although previous attempts to correlate the crescent with clinical outcomes have produced conflicting results. In this study, we investigated the clinical and morphological significance of extracapillary proliferation in a group of IgA nephropathy (IgAN) patients with regard to the Oxford classification.


METHODS
In an observational study conducted on IgAN patients, we collected a total of 114 biopsies. We diagnosed IgAN by light and immunofluorescence for all patients.


RESULTS
Of the 114 patients, 70.2% were male. The mean age of the patients was 37.7 ± 13.6 years. The mean proteinuria was 1742 ± 1324 mg/day. The mean serum creatinine was 1.6 ± 1.5 mg/dL. Twenty-five (21.9%) patient kidney biopsies had extracapillary proliferation. We found a significant positive correlation between the number of crescents and serum creatinine (p<0.001). Furthermore, we found a positive association between the nephrotic syndrome and the total number of crescents (p<0.05). Additionally, we observed a significant positive correlation between the amount of sclerosed glomeruli and extracapillary proliferation (p=0.028).


CONCLUSIONS
Our findings confirm that extracapillary proliferation has a significant association with proteinuria and sclerotic glomeruli. We anticipate that extracapillary proliferation will be included in a revision of the Oxford classification of IgAN to widen the scope of the classification.
Medical Plants Research Center, Shahrekord University of Medical Sciences, Shahrekord, Iran.
M
M
Rafieian-Kopaei
Department of Pathology, Isfahan University of Medical Sciences, Isfahan, Iran.
A
A
Baradaran
Department of Nephrology, Division of Nephropathology, Isfahan University of Medical Sciences, Isfahan, Iran.
H
H
Nasri
IgA nephropathy; Oxford classification; crescent; end-stage renal disease; endocapillary proliferation; nephrotic syndrome; proteinuria