Alessandra Thea

Hemolytic—Uremic Syndrome during Recombinant α-Interferon Treatment for Hairy Cell Leukemia

We report a case of hemolytic uremic syndrome in a patient suffering from hairy cell leukemia during recombinant α-interferon treatment. We believe that this is the first report of the occurrence of this peculiar kind of acute renal failure following α-interferon therapy. This association may suggest possible speculations regarding side effects of interferon treatment and pathogenesis of hemolytic uremic syndrome.

Hypervitaminosis B12 in Maintenance Hemodialysis Patients Receiving Massive Supplementation of Vitamin B12

We have administered routinely a multivitamin preparation containing a megadose of B12 to 106 hemodialysis patients after dialysis treatments. We found that these patients had very high levels of serum vitamin B12 which returned to original values only after a period of three years after stopping the vitamin. Discontinuing therapy had no effect on hemoglobin, mean erythrocyte corpuscular volume, or motor nerve conduction velocity. It is not known whether maintaining a prolonged high level of vitamin B12 is harmful. However, animal and epidemiologic studies have suggested that both cobalamin and cobalt may be potentially toxic. In view of the absence of demonstrable benefit and the possible risk of toxicity, we believe that the use of such megadose vitamin compounds in dialysis patients should be re-evaluated.

Concomitant Iron and Aluminum Mass Transfer Following Deferoxamine Infusion During Hemofiltration

Variable tissue overloading can alter the removal rate of iron and aluminum from uremics. Owing to its higher affinity to deferoxamine (DFO) and higher plasma concentrations, Fe could impair Al removal in cases of simultaneous body burden. Fe and Al plasma kinetics and mass transfer were therefore studied in 12 uremic patients with different Fe and Al status: six with normal ferritin levels (less than 400 micrograms/L [ng/mL]), and Al 1.4 to 4.7 mumol/L (40 to 131 micrograms/L) (group A); six with increased ferritin (greater than 2,000 micrograms/L), and Al 1.7 to 17 mumol/L (47 to 476 micrograms/L) (group B). DFO (40 and 80 mg/kg in a random sequence) was administered once a week during the first hour of the first hemofiltration (HF). The results show that in both groups and with both DFO doses, maximum Fe and Al mass transfer was achieved in the first and second HF, respectively. The 80-mg/kg dose of DFO significantly raised Al mass transfer in both groups, whereas Fe mass transfer was only slightly affected. Even though plasma Fe levels were almost always higher than Al, Al mass transfer eventually exceeded that of Fe, in both Fe-normal and Fe-overload patients. The bias towards Al in mass transfer was enhanced in both groups in the second HF, and at the higher DFO doses. Thus, DFO once a week reduced Fe loss to less than 30 mumol/wk in patients with normal ferritin levels. In both Fe and Al overloaded patients, Al can be removed, and Al mass transfer may often exceed Fe mass transfer, depending on the degree of tissue burden, the time from DFO infusion, and the DFO dose.

Three-year follow-up after withdrawal of iron therapy in uremic patients on regular dialytic treatment

SummaryIron supplementation is commonly recommended in uremic patients undergoing regular dialytic treatment in order to correct a presumed iron deficiency due to impaired absorption and dialytic losses. Serum ferritin levels show an iron overload in 83% of 136 patients on 1.25 g/year i.v. iron therapy. After the withdrawal of iron therapy, directly correlated ferritin levels and percentage transferrin saturation decreased slowly, except in carriers of HLA-A3 antigens and in polytransfused patients. In these latter patients, desferrioxamine reduced but did not normalize the iron balance. The 16 patients who never received iron therapy showed a normal iron balance over a 3-year follow-up. Despite iron-ferritin therapy, 11 patients with baseline ferritin values at the lower normal limits showed a tendency toward further depletion. Orally administered bivalent iron seems to be more promising in normalizing iron-deficient patients without potentially harmful overloading.