Over an 8-year period (January 1996 to December 2003), a total of 171 patients below the age of 15 years were diagnosed with chronic renal failure. The mean incidence rate of CRF in Kuwaiti children was found to be 38.2 per million children per year, with a peak incidence of 55 per million children per year. While the mean age at diagnosis was 33+/-12 months (range: 1 month to 15 years), the male:female ratio was 2.7:1. Etiological factors for chronic renal failure included congenital urological malformation (61.9%), chronic glomerulopathies (5.2%), hereditary nephropathies (21%), multi-system disease (0.5%), chronic pyelonephritis (without VUR) (4.6%), tumors (0.6%), ischemic renal disease (1.1%) and unknown etiology (1.7%). Thirty percent of patients reached end-stage renal disease within a mean of 18 months following diagnosis. The overall mortality before reaching ESRD was reported to be 4%. Kuwait has one of the highest incidence and prevalence rates of CRF in children. It is likely that genetic and hereditary factors are the cause of these high rates.

The distinctiveness of IgM nephropathy (IgMN) as a clinicopathologic entity is controversial. Twenty-seven children (16 males, 11 females) with IgMN as defined immunohistochemically by diffuse mesangial staining of glomeruli for IgM were compared to a group of 63 children (40 males, 23 females) with minimal change disease (MCD). While mesangial expansion was significantly greater in IgMN than in MCD (p = 0.0014), there were no significant differences between the two groups with respect to the other biopsy factors. IgMN showed a significantly higher incidence of hypertension at presentation. More than 90% of patients in both groups presented with the nephrotic syndrome which in most initially responded to prednisone. Frequently relapsing/steroid-dependent nephrotic syndrome was the most common indication for biopsy in both groups. Approximately 60% of patients from both groups received cytotoxic therapy. Eight percent of IgMN and 7% of MCD patients failed to respond to therapy. Relapse rates and mean dose of prednisone at relapse were very similar in both groups prior to biopsy. Relapse rates diminished significantly after treatment in the postbiopsy interval, but mean dose of prednisone at relapse did not change appreciably over time. None of the patients developed renal failure or hypertension in the follow-up period. At last visit 23% of IgMN and 27% of MCD had proteinuria. The results indicate that IgMN and MCD are indistinguishable clinically in children who are biopsied for the nephrotic syndrome.

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We have studied the effect of HLA-DRB1 alleles on the clinical presentation of 61 Kuwaiti Arab children with idiopathic nephrotic syndrome. DR7(*0701) was the most prevalent DR allele, found in 41/61 patients (67%) compared with 10/59 healthy controls (17%) (p<0.001). DR3(*0301-0308) allele was the second most common, found in 25% of patients compared with 26% of controls (not significant). There was no significant difference between DRB1*0701(DR7)-positive and DRB1*0701-negative patients in terms of steroid sensitivity, steroid dependency, or steroid resistance. Nevertheless, the former group had a significantly lower mean age of onset (35 months vs 53 months) and a shorter remission period following treatment with cyclophosphamide or chlorambucil (8 months vs 29 months). Our data highlight the role of the DRB 1*0701 allele in predisposing Kuwaiti Arab children with idiopathic nephrotic syndrome to a more prolonged course of the disease.

Our data suggest an association of D allele of the ACE gene insertion/deletion polymorphism and congenital urological abnormalities, which result in parenchymal damage in Kuwaiti Arab children.

Twenty-five children with hemolytic uremic syndrome (HUS) were diagnosed between January 1985 and January 2000 in the Pediatric Nephrology Unit at Mubarak Al-Kabeer Hospital. Fourteen patients (56%) had typical (D+) HUS whereas 11 (44%) had atypical (D-) HUS. No bacterial or viral pathogens could be isolated in the majority of cases. The atypical HUS group had more severe anemia (P=0.03), which was significantly more prolonged than in the typical HUS group (P=0.0028). There was no significant difference between the two groups in the mean maximum serum creatinine (P=0.1), blood urea nitrogen values (P=0.8) and severity of leukocytosis (P=0.4). Anuria and the need for dialysis were not significantly different between the two groups (P=0.1 and 0.05, respectively). Mortality was significantly higher in the D- HUS patients (P<0.0001). Recurrence of HUS was documented in 63.3% of the D- HUS group compared to 14.2% of the D+ HUS group (P=0.0053). Family history of HUS was reported in 72.7% of the atypical HUS group and 14.2% of the typical HUS group. There were no significant differences in chronic renal sequelae between the two groups. In conclusion, the pathogenesis of HUS in Kuwaiti children appears to be influenced by genetic factors rather than certain environmental pathogens. Atypical HUS has a higher mortality rate, a definite familial tendency and a high relapse rate.

Background Urinary tract infection (UTI) is common in pediatrics. Infection of the upper urinary tract may cause renal scarring, and subsequently renal failure and hypertension. Permanent renal damage has been suggested to be caused by the host inflammatory response. Therefore, it is crucial to understand the host defense mechanisms against such infection in order to make timely diagnosis. The aim of this study was to evaluate interleukin-6 (IL-6) and IL-8 as potential biomarkers in differentiating acute pyelonephritis (AP) from cystitis (Cys) in children. Methods Forty-three children (21 with AP and 22 with Cys) were included. Serum and urinary IL-6 and IL-8 were measured during the acute phase (within 12 hours of presentation) and the convalescent phase (8 weeks post-infection). Thirty-eight healthy children were included as controls. Results During the acute phase, the mean urinary IL-6 level in the Cys group was significantly higher than that in the controls (17.8 pg/mL vs 14.8 pg/mL, P=0.03), while the serum levels were significantly higher in both the Cys and AP groups than in the controls (19.5 pg/mL, 19.4 pg/mL, 15 pg/mL, P=0.005 and 0.02, respectively). During the convalescent phase, serum and urinary IL-6 levels were higher in patients than in controls. Urinary IL-8 levels were significantly higher in both the AP and Cys groups compared to controls (206.5 pg/mL, 291.8 pg/mL, 89.4 pg/mL, P=0.05 and 0.02, respectively) during the acute phase. Serum IL-8 was not significantly different between the 3 groups. Nonetheless, no significant differences were found between the AP and Cys groups, in urinary or serum levels of IL-6 or IL-8, during both phases. Conclusion IL-6 and IL-8 levels are elevated in patients with UTI. However, the levels did not differentiate between AP and cystitis. Further studies are warranted to evaluate their roles as indicators of the site of UTIs.

Background/aimThe role of pro-inflammatory cytokines in the immunopathogenesis of idiopathic nephrotic syndrome had been widely postulated. Reports on the release of cytokines, during idiopathic nephrotic syndrome (INS) activation, were conflicting in defining a specific interleukin pattern during relapse and remission of the disease. The aim of this study was to explore the role of IL-1β, IL-6 and IL-8 in the pathophysiology of INS during relapse and remission.Patients and methodsA total of 37 INS patients were included. Their demographic and biochemical data were reviewed. Levels of IL-1β, IL-6 and IL-8 were measured in the urine of patients during relapse and remission of the disease. Urine samples from 30 age- and sex-matched controls were checked for the same 3 cytokines.ResultsMean age of patients at study was 6.4 ± 3.2 years (range: 14 months–12 years). Male:female ratio was 24:13. Mean serum creatinine was 47 ± 13 μmol/L, and mean serum albumin was 21 ± 7 g/L. Mean urinary IL-1β, IL6 and IL8 levels, corrected to urinary creatinine, in patients during relapse were 132.94 ± 654.97, 217.82 ± 1124.31 and 150.227 ± 523.97 pg/μmol compared to 9.11 ± 40.75, 0.146 ± 0.652, and 6.455 ± 24.53 pg/μmol in controls, respectively (P = 0.02, 0.03 and 0.014, respectively). No significant difference was reported in the mean level of the 3 cytokines compared to controls during remission (P = 0.94, 0.092 and 0.076).ConclusionOur results support the role of T-cell activation and the subsequent release of IL-1β, IL6 and IL8 in the pathogenesis of relapses in INS. The use of steroid-sparing cytokine blockers in managing relapses of INS remains a tempting challenge.