Glomerulopathy in Kuwait: the spectrum over the past 7 years

There are few studies that examine, prospectively, the epidemiological profile of glomerulopathy (GP) and its clinicopathological correlation. All patients referred to Al-Amiri renal center in Kuwait from January 1st, 1995 to December 31st, 2001 were screened for GP. Detailed clinical data were collected and serological markers were done. Renal biopsy was performed whenever indicated. During those 7 years, a total of 584 patients were diagnosed, on histological basis, to have GP, 315 of whom were Kuwaiti nationals. During the same period of the study, 26 patients presented with bilateral small kidneys, history of proteinuria > 2 g/day and lacked systemic manifestations of autoimmune disease. Furthermore, 164 patients with clinical manifestations of diabetic glomerulosclerosis were not subjected to kidney biopsy. Hence, the calculated annual incidence rate of GP in Kuwaiti nationals was 34.5 per 100,000 population (PTP). The calculated rate of diabetic glomerulosclerosis was 13.4 PTP and that of nondiabetic 21.1 PTP. The calculated incidence rates of GP increased with age and were twice as high in males compared to females. Vasculitis was more common in elderly males while SLE nephritis was a disease of adults, 88.7% of whom were females. In the subgroup of primary GP, focal segmental glomerulosclerosis was the most common histological lesion accounting for 18.0% of the total biopsies in Kuwaiti patients, yet only 36.8% of those who fulfilled the criteria of primary type. Minimal change disease was the second primary GP (13.0%), followed by immunoglobulin A deposition disease (7.9%) and membranous glomerulonephritis (5%). Autoimmune diseases such as systemic lupus erythematosus (SLE) and vasculitis were common. Interestingly, only 44 of 72 (61.1%) of patients with SLE and 11 of the 62 (17.7%) of patients with vasculitis presented with rapidly progressive glomerulonephritis. On the other hand, 10 of 58 (17.2%) patients with nephroangiosclerosis presented with renal failure and protein excretion > 2 g/day simulating primary GP. Furthermore, only 21 of 40 (52.5%) patients with IgA nephropathy presented with "benign disease". Prospective studies are essential to ascertain the actual incidence and etiology of GP. The loose clinicopathological correlation in GP dictates an aggressive diagnostic approach in its study and management.