ABSTRACT
CONTEXT.: Galactose-deficient immunoglobulin A1 (Gd-IgA1) deposition in the renal mesangium plays a role in the pathogenesis of IgA nephropathy. OBJECTIVE.: To assess the serum Gd-IgA1 level in biopsy-proven IgA nephropathy cases on diagnosis and 3 months post treatment and its relation with histologic Oxford classification. DESIGN.: In this hospital-based prospective cohort study, 40 cases and 20 controls were enrolled. Serum samples of biopsy-proven IgA nephropathy cases collected on the day of biopsy and 3 months post treatment were evaluated. Solid-phase ELISA (enzyme-linked immunosorbent assay) was performed for assessment of Gd-IgA1 level. All renal biopsies were scored by using Oxford Classification (C-MEST score). The association of serum Gd-IgA1 levels with other established prognostic parameters was assessed. To estimate the prognostic value of markers, logistic regression analysis and Kruskal-Wallis ANOVA (analysis of variance) were used. RESULTS.: Significant difference was observed in the serum Gd-IgA1 level values in the IgA nephropathy cases and healthy controls (P = .001) at baseline. However, no significant correlation between serum Gd-IgA1 levels at baseline and 3 months of follow-up (P = .31) or between baseline levels and age, proteinuria, hematuria, or estimated glomerular filtration rate was noted. There was no significant correlation between C-MEST score and serum Gd-IgA1 levels at baseline (P > .05); however, the distribution of Gd-IgA1 at 3 months was found to differ significantly between different grades of S score (P = .008). CONCLUSIONS.: Serum Gd-IgA1 levels may be of utility in predicting disease progression in IgA nephropathy cases. Measurement of serum Gd-IgA1 levels for the diagnosis and prognosis of IgA nephropathy may preclude the need for invasive renal biopsies.
ABSTRACT
Background: Hyperphosphatemia is linked to increased mortality and morbidity in patients on hemodialysis. Currently, the phosphate intake and dialytic removal in predominantly vegetarian patients on twice-weekly dialysis is not well studied. Materials and methods: This prospective, study recruited patients on twice-weekly dialysis of at least 3 months duration. Baseline clinical variables were measured. Dietary protein and phosphorus intake was assessed using a validated food frequency questionnaire. Phosphate binder use was assessed, hourly blood was collected for serum phosphorus during dialysis, and spent dialysate was collected to estimate cumulative phosphorus removal during the session. Results: Forty (67%) of the 60 patients studied were vegetarians. Twenty-eight (48%) were hyperphosphatemic, and 15 (25%) had serum parathormone (PTH) >500 pg/ml. The mean phosphorus intake was 1247 (±312) mg/day, the mean serum phosphorus was 5.49 (±2.01) mg/dl, and the mean dialytic phosphorus removal was 910 (±383) mg/session. Up to 67% of the study population took calcium-based phosphate binders, 25% took sevelamer carbonate, and 40% took activated vitamin D preparation. The lowest tertiles of phosphorus intake correlated with low energy-adjusted protein intake and hypoalbuminemia. Hyperphosphatemic subjects had better nutritional indices (mid-upper arm circumference and body mass index). Dietary intake and serum phosphorus levels were not mutually associated, but both were strongly correlated with total phosphorus removal in the spent dialysate. Serum phosphorus levels fell by 32% by thefirst hour of hemodialysis. Conclusion: Twice-weekly dialysis is often practised in resource-limited Asian countries. However, due to a predominantly vegetarian diet, hyperphosphatemia was noted only in up to half of the patients, despite twice-weekly hemodialysis schedules. This reinforces the fact that plant-based dietary phosphate is less well absorbed.
