Renal Biopsy Findings of Patients Presenting with Isolated Hematuria: Disease Associations

Abstract
Background: Most nephrologists have believed that patients with isolated hematuria (IH) generally do not require treatment and have a good prognosis. The aim of this study was to analyze the pathological characteristics and emphasize the importance of renal biopsy for patients with IH. Methods: The pathological characteristics of 90 patients with IgA nephropathy confirmed by renal biopsy and presenting with IH were reviewed. We analyzed their pathological features according to the Oxford classification by using light and immunofluorescence. Results: Total samples included 68 females and 22 males. The age of onset with IH focuses on 20–30 years. At presentation, the focal and/or segmental glomerulosclerosis (FSGS) was the most frequent diagnosis (52.22%). The distribution of hematuria focused on 20–40 thousand. 46.67% of cases had global glomerulosclerosis which excluded the physical glomerular sclerosis, and the incidence of crescent formation was 24.44%. However, the proportion of glomerular sclerosis was mainly concentrated in less than 10%. Direct immunofluorescence showed simple IgA deposition was the most common (43.33%). 46.67% of patients had accompanying complement deposition, and 92.89% had complement 3 deposition. According to the Oxford classification, M1S₀E₀T₀ accounted for 53.33%. The incidence of M, S, E, and T was 100, 30, 14.44, and 22.22% respectively. 46.67% of patients included two or more pathological lesions. Conclusions: FSGS played an important role in patients with IgA nephropathy who presented with IH. For those patients, renal biopsy was a valuable diagnostic tool and should be offered in clinical settings to provide them with maximal potential benefits.