Islet transplantation is associated with improvement of renal function among uremic patients with type I diabetes mellitus and kidney transplants.
The potential effects of islet transplantation on the renal function of 36 patients with type I diabetes mellitus and kidney transplants were studied with 4 yr of follow-up monitoring. Kidney-islet recipients were divided into two groups, i.e., patients with successful islet transplants (SI-K group) (n = 24, fasting C-peptide levels of >0.5 ng/ml for >1 yr) and patients with unsuccessful islet transplants (UI-K group) (n = 12, fasting C-peptide levels of <0.5 ng/ml). Kidney graft survival rates and function, urinary albumin excretion rates, and sodium handling were compared. Na(+)/K(+)-ATPase activity in protocol kidney biopsies and in red blood cells was cross-sectionally analyzed. The SI-K group demonstrated better kidney graft survival rates (100, 83, and 83% at 1, 4, and 7 yr, respectively) than did the UI-K group (83, 72, and 51% at 1, 4, and 7 yr, respectively; P = 0.02). The SI-K group demonstrated reductions in exogenous insulin requirements and higher C-peptide levels, compared with the UI-K group, whereas GFR values were similar. Microalbuminuria (urinary albumin index) increased significantly in the UI-K group only (UI-K, from 92.0 +/- 64.9 to 183.8 +/- 83.8, P = 0.05; SI-K, from 108.5 +/- 53.6 to 85.0 +/- 39.0, NS). In the SI-K group, but not in the UI-K group, natriuresis decreased at 2 and 4 yr (P < 0.01). The SI-K group demonstrated greater Na(+)/K(+)-ATPase immunoreactivity in renal tubular cells (P = 0.05) and higher activity in red blood cells (P = 0.03), compared with the UI-K group. The Na(+)/K(+)-ATPase activity in red blood cells was positively correlated with circulating C-peptide levels but not with glycated hemoglobin levels. Successful islet transplantation was associated with improvements in kidney graft survival rates and function among uremic patients with type I diabetes mellitus and kidney grafts.
Fiorina
Paolo
P
Departments of Medicine and Surgery, San Raffaele Scientific Institute, Milan, Italy.
Folli
Franco
F
Zerbini
Gianpaolo
G
Maffi
Paola
P
Gremizzi
Chiara
C
Di Carlo
Valerio
V
Socci
Carlo
C
Bertuzzi
Federico
F
Kashgarian
Michael
M
Secchi
Antonio
A
D000418:Albumins / Q000378:metabolism; D001794:Blood Pressure; D002096:C-Peptide / Q000737:chemistry; D003922:Diabetes Mellitus, Type 1 / Q000150:complications / Q000378:metabolism*; D003928:Diabetic Nephropathies / Q000473:pathology; D004912:Erythrocytes / Q000378:metabolism; D005919:Glomerular Filtration Rate; D006084:Graft Rejection; D006085:Graft Survival; D006801:Humans; D016381:Islets of Langerhans Transplantation / Q000379:methods*; D007668:Kidney / Q000378:metabolism / Q000502:physiology*; D016030:Kidney Transplantation; D012084:Renin-Angiotensin System; D012964:Sodium / Q000378:metabolism; D000254:Sodium-Potassium-Exchanging ATPase / Q000378:metabolism; D013997:Time Factors; D014511:Uremia / Q000150:complications / Q000378:metabolism*
D000418:Albumins; D002096:C-Peptide; D012964:Sodium; D000254:Sodium-Potassium-Exchanging ATPase