[Lactic acidosis and severe hyperkalemia in a diabetic patient treated with metformin and enalapril: influence of acute renal disease and drugs]. / Acidosi lattica ed iperpotassiemia grave in un paziente diabetico in terapia con metformina ed enalapril: influenza di patologia renale acuta e farmaci.

A 71 year old hypertensive and non insulin-dependent diabetic patients with moderate renal insufficiency taking 500 mg/d of metformin and 5 mg/d of enalapril, developed metabolic acidosis characterized by fairly elevated anion gap, hyperchloremia, severe hyperkalemia, normal plasma level of beta-hydroxybutyric acid, absence of ketonuria and high plasma level of lactic acid. This biochemical feature allowed us to ascribe the pathogenesis of metabolic acidosis both to the increased plasma level of lactic acid and to the type IV renal tubular acidosis syndrome, the precipitating factor being an infection of urinary tract (as we assumed on the basis of the urine culture). The patient was dehydrated and lethargic; the ECG revealed the presence of nonparoxysmal junctional tachycardia. The clinical evolution was favorable thanks to the treatment with the infusion of isotonic saline solutions, mild alkalinizing solutions, low-dose regular insulin and antibiotics. It is likely that metformin and enalapril, regularly assumed by the patient, could have played a iatrogenic role even if they were taken in low dosages. This event points out the importance of complying with the indications and especially the contraindications of these drugs, to avoid life threatening complications as that one occurred in this case.

[Major histocompatibility complex antigens in a population of insulin-dependent diabetics living in the Province of Varese]. / Gli antigeni del sistema maggiore di istocompatibilità in una popolazione di soggetti diabetici insulinodipendenti residenti in Provincia di Varese.

The HLA haplotype was studied in 143 newly diagnosed insulin-dependent diabetic subjects resident in the province of Varese who attended the clinic between March 1987 and June 1993. The frequency with which the various loci of the histocompatibility system were observed was compared with that reported in 83 non-diabetic subjects not related to the diabetics taking part in the study. The relative risk (RR) was calculated using these data and its statistical significance was assessed using the chi-square test. 70.6% of subjects were positive for loci DR3 or DR4, whereas only 7.7% (11 subjects) were found to be carriers of eterozygous DR3-DR4. This percentage is lower than that generally reported in the literature. However, even in the authors personal experience heterozygous DR3-DR4 subjects represent the greatest relative risk in absolute terms (RR = 14.49). The presence of antigen DQw2 is strongly indicative of the disease, both when it is found in an isolated form and in association with DR3 or DR4 (RR = 2.56, 4.03, 3.29 respectively). The DR3/DR4/DQw2 axis gives a RR of 9.17. The associations of B8/DR3/DR4 and B8/DR3/DQw2 give a RR of 9.17, whereas the B8/DR4 axis gives a RR of 10.47. In this series, the lowest risk of developing the disease was provided by the DR2/DR7 axis (RR 0.28); DR2 alone gave a RR of 1.84 and DR7 alone gave a RR of 0.62. The discrepancies reported with the literature may be related to ethnic variations, thus giving added weight to the hypothesis of the heterogeneity of insulin-dependent diabetes mellitus.