Michael Mauer

BACKGROUND: In patients with type I diabetes mellitus who do not have uremia and have not received a kidney transplant, pancreas transplantation does not ameliorate established lesions of diabetic nephropathy within five years after transplantation, but the effects of longer periods of normoglycemia are unknown. METHODS: We studied kidney function and performed renal biopsies before pancreas transplantation and 5 and 10 years thereafter in eight patients with type I diabetes but without uremia who had mild to advanced lesions of diabetic nephropathy at the time of transplantation. The biopsy samples were analyzed morphometrically. RESULTS: All patients had persistently normal glycosylated hemoglobin values after transplantation. The median urinary albumin excretion rate was 103 mg per day before transplantation, 30 mg per day 5 years after transplantation, and 20 mg per day 10 years after transplantation (P=0.07 for the comparison of values at base line and at 5 years; P=0.11 for the comparison between base line and 10 years). The mean (+/-SD) creatinine clearance rate declined from 108+/-20 ml per minute per 1.73 m2 of body-surface area at base line to 74+/-16 ml per minute per 1.73 m2 at 5 years (P<0.001) and 74+/-14 ml per minute per 1.73 m2 at 10 years (P<0.001). The thickness of the glomerular and tubular basement membranes was similar at 5 years (570+/-64 and 928+/-173 nm, respectively) and at base line (594+/-81 and 911+/-133 nm, respectively) but had decreased by 10 years (to 404+/-38 and 690+/-111 nm, respectively; P<0.001 and P=0.004 for the comparisons with the base-line values). The mesangial fractional volume (the proportion of the glomerulus occupied by the mesangium) increased from base line (0.33+/-0.07) to 5 years (0.39+/-0.10, P=0.02) but had decreased at 10 years (0.27+/-0.02, P=0.05 for the comparison with the baseline value and P=0.006 for the comparison with the value at 5 years), mostly because of a reduction in mesangial matrix. CONCLUSIONS: Pancreas transplantation can reverse the lesions of diabetic nephropathy, but reversal requires more than five years of normoglycemia.

BACKGROUND: Nephropathy and retinopathy remain important complications of type 1 diabetes. It is unclear whether their progression is slowed by early administration of drugs that block the renin-angiotensin system. METHODS: We conducted a multicenter, controlled trial involving 285 normotensive patients with type 1 diabetes and normoalbuminuria and who were randomly assigned to receive losartan (100 mg daily), enalapril (20 mg daily), or placebo and followed for 5 years. The primary end point was a change in the fraction of glomerular volume occupied by mesangium in kidney-biopsy specimens. The retinopathy end point was a progression on a retinopathy severity scale of two steps or more. Intention-to-treat analysis was performed with the use of linear regression and logistic-regression models. RESULTS: A total of 90% and 82% of patients had complete renal-biopsy and retinopathy data, respectively. Change in mesangial fractional volume per glomerulus over the 5-year period did not differ significantly between the placebo group (0.016 units) and the enalapril group (0.005, P=0.38) or the losartan group (0.026, P=0.26), nor were there significant treatment benefits for other biopsy-assessed renal structural variables. The 5-year cumulative incidence of microalbuminuria was 6% in the placebo group; the incidence was higher with losartan (17%, P=0.01 by the log-rank test) but not with enalapril (4%, P=0.96 by the log-rank test). As compared with placebo, the odds of retinopathy progression by two steps or more was reduced by 65% with enalapril (odds ratio, 0.35; 95% confidence interval [CI], 0.14 to 0.85) and by 70% with losartan (odds ratio, 0.30; 95% CI, 0.12 to 0.73), independently of changes in blood pressure. There were three biopsy-related serious adverse events that completely resolved. Chronic cough occurred in 12 patients receiving enalapril, 6 receiving losartan, and 4 receiving placebo. CONCLUSIONS: Early blockade of the renin-angiotensin system in patients with type 1 diabetes did not slow nephropathy progression but slowed the progression of retinopathy. (ClinicalTrials.gov number, NCT00143949.)

Fabry disease is an X-linked lysosomal storage disorder caused by mutations in the GLA gene leading to deficient α-galactosidase A activity, glycosphingolipid accumulation, and life-threatening complications. Phenotypes vary from the "classic" phenotype, with pediatric onset and multi-organ involvement, to later-onset, a predominantly cardiac phenotype. Manifestations are diverse in female patients in part due to variations in residual enzyme activity and X chromosome inactivation patterns. Enzyme replacement therapy (ERT) and adjunctive treatments can provide significant clinical benefit. However, much of the current literature reports outcomes after late initiation of ERT, once substantial organ damage has already occurred. Updated monitoring and treatment guidelines for pediatric patients with Fabry disease have recently been published. Expert physician panels were convened to develop updated, specific guidelines for adult patients. Management of adult patients depends on 1) a personalized approach to care, reflecting the natural history of the specific disease phenotype; 2) comprehensive evaluation of disease involvement prior to ERT initiation; 3) early ERT initiation; 4) thorough routine monitoring for evidence of organ involvement in non-classic asymptomatic patients and response to therapy in treated patients; 5) use of adjuvant treatments for specific disease manifestations; and 6) management by an experienced multidisciplinary team.