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Adult patients with transfusional hemosiderosis were given ascorbic acid and treated with the iron chelator, desferrioxamine B. The drug was administered by continuous subcutaneous or intravenous infusions using a light weight portable constant infusion device. On this regimen, four of the five patients studied were able to excrete significant amounts of iron (greater than 35 mg/da) when receiving a daily desferrioxamine dose of 1.5 to 2.2 g. Continuous subcutaneous infusion was well tolerated and about 80 per cent as effective as intravenous therapy in chelating iron. The number of prior transfusions, the hepatic iron content and the serum ferritin levels appear to be useful in predicting which patients will respond to iron chelation therapy, especially if there is little bone marrow erythropoietic activity. One patient with ineffective erythropoiesis did not have significantly increased hepatic iron stores but responded to the administration of desferrioxamine. Continuous subcutaneously administered desferrioxamine may prove to be adaptable for long-term outpatient therapy, allowing patients with ongoing transfusion requirements to go into negative iron balance. Long-term studies will be needed to demonstrate reversal of endocrine, hepatic and cardiac dysfunction secondary to iron deposition in these patients.

Fifty-eight patients with severe, progressive multiple sclerosis were prospectively randomized to one of three treatments: 20 received intravenous ACTH, 20 received high-dose intravenous cyclophosphamide plus ACTH, and 18 were placed on a regimen consisting of plasma exchange, low-dose oral cyclophosphamide, and ACTH. The three groups were similar in age, sex, duration and type of disease, and degree of disability. Before treatment and six months and one year after treatment, a disability-status score, ambulation index, and functional-status score were determined, and a quantitative neurologic examination was performed. In the ACTH group, the number of patients stabilized or improved was 8 of 20 at six months and 4 of 20 at one year; in the cyclophosphamide-ACTH group, 18 of 20 at six months and 16 of 20 at one year; and in the plasma exchange group, 11 of 18 at six months and 9 of 18 at one year. High-dose cyclophosphamide plus ACTH was most effective in halting progression of the disease at both 6 and 12 months (at 12 months, cyclophosphamide-ACTH vs. ACTH, P = 0.0004; cyclophosphamide-ACTH vs. plasma exchange, P = 0.087). Thus, progressive multiple sclerosis may be stabilized by short-term, intensive immunosuppression with cyclophosphamide plus ACTH.

Sickle cell (Hb SS) anemia is considered a normochromic-normocytic hemolytic disorder. In 53 patients with Hb SS (mean reticulocyte values 16.8%), the authors observed that mean corpuscular hemoglobin (MCH) was 29.8 +/- 2.4 mu microgram and mean corpuscular hemoglobin (MCV) was 88.1 +/- 6.8 cu micrometers. In contrast, patients in a comparable hemolytic-disease group unrelated to hemoglobinopathies (mean reticulocyte count = 15.7%) had a higher MCH (33.0 +/- 1.8 mu microgram) and larger MCV (97 +/- 5.3 cu micrometers). These data indicate that Hb SS disease is associated with "relative microcytosis," presumably a consequence of reduced hemoglobin production.

Patients requiring chronic transfusions deposit large quantities of iron throughout their reticuloendothelial and parenchymal systems. Diabetes mellitus, hepatic fibrosis, and cardiomyopathy are the ultimate pathologic manifestations. One mechanism for decreasing the rate of iron loading would be to transfuse only the youngest cohort of cells from a donor (neocytes). At the same time the patient's oldest red cells are being removed (neocyte-gerocyte exchange). In this manuscript we describe techniques presently available for such a procedure.

Treatment of transfusion-induced iron overload by daily intramuscular injection of the chelator desferrioxamine has not produced impressive urinary iron excretion. We attempted to augment net iron excretion by altering both the route and quantity of chelator administered. Two ascorbic acid-replete patients excreted a mean of 14.5 mg of iron per 24 hours after a single intramuscular injection of 750 mg of desferrioxamine. Excretion increased to a mean of 44.9 mg when this dose was delivered by a continuous 24-hour intravenous infusion. When the intravenous dose of chelator was increased incrementally to as high as 16,000 mg per 24 hours, iron excretion increased up to 180 mg per day. At these high-dose levels, efficiency of binding of iron to chelator was compromised. Constant exposure of the labile iron pool to a chelating agent markedly enhances net iron excretion in splenectomized transfusion-dependent patients.

Since deferoxamine B, when administered as a single daily intramuscular injection of 0.75 g, is unable to promote sufficient urinary iron excretion to achieve net negative iron balance in siderosis, we evaluated its administration as a constant infusion over 24 hours. We compared intravenous and subcutaneous routes in 24 siderotic patients who had excreted 420 to 630 mg (mean, 480 mg) of iron per month on intramuscular therapy. With the intravenous route urinary iron excretions increased to 570 to 3690 mg (mean, 1595 mg) per month. Constant subcutaneous delivery was 90 per cent as effective as intravenous administration on a dose-for-dose basis. Noteworthy net cumulative urinary iron excretions (urinary iron excretions minus transfused iron), often in excess of 1 g per month, have been maintained in all patients. Constant subcutaneous deferoxamine administration may prove to be an effective and practical means of eliminating large quantities of iron in siderosis.

Cation composition, cellular hydration, and adenosinetriphosphate (ATP) content were measured in irreversible sickle cells (ISC's) separated from the blood of patients with sickle cell anaemia. Total monovalent cation (Na+ + K+) content was markedly reduced in ISC's and this largely was due to cell K+ depletion. Corresponding to the reduced cation content, cells were dehydrated as indicated by a reduced mean cell volume. ISC's also appeared to be grossly depleted of ATP. These biochemical characteristics allow us to expand the definition of ISC's beyond morphologic characteristics. In addition, these chemical alterations provide a means for elucidating the mechanism of ISC production in vitro.