PROGNOSTIC FACTORS IN IGA NEPHROPATHY

초록

. IgA nephropathy is a primary renal disease characterized by prominent mesangial IgA deposition without systemic disease. Recurrent hematuria and proteinuria are the main clinical manifestations and the most common renal diseases in patients with recurrent hematuria. The natural disease course of IgA nephropathy has been thought to be a slowly progressive disease, but about 20% of patients develop an end-stage renal disease, so the clinical manifestations and the factors affecting the prognosis of this disease have very important clinical aspects. We investigated the clinical features and renal pathologic findings for 43 patients with IgA nephropathy during the past 4 years. The following results were obtained: (1) The mean age of the patients was 30 years and 79% were distributed between 20 to 40 years. The male to female ratio was 1:1. (2) The most common clinical symptoms were gross hematuria (47%), microscopic hematuria (21%) and 12 of 43 cases (28%) complained of associated loin pains. (3) Precipitating factors could be found in 15 cases (35%) and upper respiratory tract infection was the most common precipitating factor in 10 cases. The mean duration of symptom onset, following URI like symptoms, was 6 days. (4) Significant proteinuria (more than 1 g/day) was noted in 10 cases (44%) including 12% of nephrotic range proteinuria. (5) Mean serum creatinine level was significantly higher in males, 1.20 0.56 mg/dl, than in females, 0.77 0.18 mg/dl (P < 0.05). (6) Mean serum creatinine level showed a statistically significant positive correlation with age (r = 0.34), mean blood pressure (r = 0.71) and 24 hour proteinuria (r = 0.35) (P < 0.05). (7) Twenty-four hour urine protein was statistically, significantly and positively correlated with age (r = 0.47) and negatively correlated with mean blood pressure (r = —0.37) and serum albumin level (r = —0.37) (P < 0.05). (8) Renal pathologic grading according to ISKDC classification revealed Grade I, 28%; Grade II, 30%; Grade III, 28%; Grade IV, 9% and Grade V, 5%. Through immunofluorescent microscopy, IgA was found without other immunoglobulins in 51%; with 1gM 40%; with IgG 2%. (9) Of these cases, 9% progressed to deterioration of renal function during a mean of 17months follow-up duration. Mean blood pressure and 24 hour proteinuria of these patients were 152 mm Hg and 4.25 g/day, respectively. Renal biopsy showed arterial nephrosclerosis in all 4 cases. From the above results, male sex, old age, mean blood pressure, 24 hour proteinuria and especially arterial nephrosclerosis, may have a significant correlation with the prognosis of IgA nephropathy.