David G. Nathan

Survival in Medically Treated Patients with Homozygous β-Thalassemia

Background The prognosis of patients with homozygous β-thalassemia (thalassemia major) has been improved by transfusion and iron-chelation therapy. We analyzed outcome and prognostic factors among patients receiving transfusions and chelation therapy who had reached the age at which iron-induced cardiac disease, the most common cause of death, usually occurs. Methods Using the duration of life without the need for either inotropic or antiarrhythmic drugs as a measure of survival without cardiac disease, we studied 97 patients born before 1976 who were treated with regular transfusions and chelation therapy. We used Cox proportional-hazards analysis to assess the effect of prognostic factors and life-table analysis to estimate freedom from cardiac disease over time. Results Of the 97 patients, 59 (61 percent) had no cardiac disease; 36 (37 percent) had cardiac disease, and 18 of them had died. Univariate analysis demonstrated that factors affecting cardiac disease-free survival were age at the start of che...

Quantitative Nitroblue Tetrazolium Test in Chronic Granulomatous Disease

Abstract Chronic granulomatous disease is an X-linked defect in the killing of certain bacteria by peripheral blood granulocytes and may be detected with the nitroblue tetrazolium (NBT) test. The r...

Hydroxyurea enhances fetal hemoglobin production in sickle cell anemia

Hydroxyurea, a widely used cytotoxic/cytostatic agent that does not influence methylation of DNA bases, increases fetal hemoglobin production in anemic monkeys. To determine its effect in sickle cell anemia, we treated two patients with a total of four, 5-d courses (50 mg/kg per d, divided into three oral doses). With each course, fetal reticulocytes increased within 48-72 h, peaked in 7-11 d, and fell by 18-21 d. In patient I, fetal reticulocytes increased from 16.0 +/- 2.0% to peaks of 37.7 +/- 1.2, 40.0 +/- 2.0, and 32.0 +/- 1.4% in three successive courses. In patient II the increase was from 8.7 +/- 1.2 to 50.0 +/- 2.0%. Fetal hemoglobin increased from 7.9 to 12.3% in patient I and from 5.3 to 7.4% in patient II. Hemoglobin of patient I increased from 9.0 to 10.5 g/dl and in patient II from 6.7 to 9.9 g/dl. Additional single-day courses of hydroxyurea every 7-20 d maintained the fetal hemoglobin of patient I t 10.8-14.4%, and the total hemoglobin at 8.7-10.8 g/dl for an additional 60 d. The lowest absolute granulocyte count was 1,600/mm3; the lowest platelet count was 390,000/mm3. The amount of fetal hemoglobin per erythroid burst colony-forming unit (BFU-E)-derived colony cell was unchanged, but the number of cells per BFU-E-derived colony increased. Although examination of DNA synthesis in erythroid marrow cells in vitro revealed no decreased methylcytidine incorporation, Eco RI + Hpa II digestion of DNA revealed that hypomethylation of gamma-genes had taken place in vivo after treatment. This observation suggests that hydroxyurea is a potentially useful agent for the treatment of sickle cell anemia and that demethylation of the gamma-globin genes accompanies increased gamma-globin gene activity.

Leukocyte Oxidase: Defective Activity in Chronic Granulomatous Disease

The intact leukocytes of two children with chronic granulomatous disease fail to reduce nitroblue tetrazolium during phagocytosis. This is due to defective operation of an oxidase of reduced nicotinamide adenine dinucleotide that is insensitive to cyanide and that indirectly stimulates the oxidation of glucose-6-phosphate in leukocytes. Such leukocytes undergo no increase in oxygen consumption or in activity of the hexose monophosphate shunt during phagocytosis, although lactate production is normal. The addition of nitroblue tetrazolium to a leukocyte suspension appears to provide a sensitive diagnostic screening test for this disease.

Effectiveness and safety of ICL670 in iron-loaded patients with thalassaemia: a randomised, double-blind, placebo-controlled, dose-escalation trial

BACKGROUND Transfusional iron overload is a potentially fatal complication of the treatment of thalassaemia. We aimed to investigate short-term efficacy, pharmacokinetic/pharma- codynamic (PK/PD) relations, and safety of ICL670, a novel, tridentate, orally active iron chelator. METHODS We enrolled 24 patients and divided them into three cohorts consisting of a minimum of seven individuals. Patients were admitted to a metabolic unit and consumed a diet with a defined content of iron. Two patients in each cohort were randomly allocated placebo. Five or more patients received one daily dose of ICL670 at 10, 20, or 40 mg x kg(-1) x day(-1), from day 1 to 12. Net iron excretion (NIE) was measured between days 1 and 12. Primary objectives included assessment of safety and tolerability (measured by adverse events and clinical laboratory monitoring), pharmacokinetics (measured as drug and drug-iron complex), and cumulative net iron excretion (measured by faecal and urine output minus food input). Analysis was for efficacy. FINDINGS ICL670 was absorbed promptly and was detectable in the blood for 24 h. Exposure (area under the curve of plasma concentration) to ICL670 at pharmacokinetic steady state was proportional to dose. All three doses resulted in positive NIE. The NIE achieved at 20mg x kg(-1) day(-1) would prevent net iron accumulation in most patients transfused with 12-15 mL packed red-blood-cells kg(-1) month(-1), equivalent to 0.3-0.5 mg iron kg(-1) x day(-1). A linear relation (PK/PD) was recorded between exposure to ICL670 and total iron excretion, by contrast with placebo (r2=0.54, p<0.0001). Skin rashes were noted in four patients treated at 20 and 40 mg x kg(-1) x day(-1), and one patient also developed grade 2 transaminitis. INTERPRETATION ICL670 given once daily at 20 mg/kg seems to be an effective orally active iron chelator and is reasonably well tolerated. Long-term studies are now necessary to establish the practical contribution of this drug.

Continuous Subcutaneous Administration of Deferoxamine in Patients with Iron Overload

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.

Ribosomal Protein S24 Gene Is Mutated in Diamond-Blackfan Anemia

Diamond-Blackfan anemia (DBA) is a rare congenital red-cell aplasia characterized by anemia, bone-marrow erythroblastopenia, and congenital anomalies and is associated with heterozygous mutations in the ribosomal protein (RP) S19 gene (RPS19) in approximately 25% of probands. We report identification of de novo nonsense and splice-site mutations in another RP, RPS24 (encoded by RPS24 [10q22-q23]) in approximately 2% of RPS19 mutation-negative probands. This finding strongly suggests that DBA is a disorder of ribosome synthesis and that mutations in other RP or associated genes that lead to disrupted ribosomal biogenesis and/or function may also cause DBA.

AUTOLOGOUS BONE-MARROW TRANSPLANTATION IN CALLA-POSITIVE ACUTE LYMPHOBLASTIC LEUKAEMIA AFTER IN-VITRO TREATMENT WITH J5 MONOCLONAL ANTIBODY AND COMPLEMENT

A monoclonal antibody (J5) specific for the common acute-lymphoblastic-leukaemia antigen (CALLA) was used for in-vitro pre-treatment of bone-marrow before autologous transplantation in four patients with CALLA-positive acute lymphoblastic leukaemia (ALL) in relapse, who did not have HLA-compatible donors. After remission induction and intensification, bone-marrow cells were harvested, treated with J5 antibody and rabbit complement, and cryopreserved in liquid nitrogen. Patients received ablative chemotherapy and total-body irradiation before reinfusion of autologous J5-treated bone marrow. The transplantation protocol was well tolerated, and engraftment of normal myeloid cells occurred in all for patients. Two patients have continued in unmaintained remission with complete haematopoietic reconstitution for more than 1 year after autologous transplantation.

Prevention of Cardiac Disease by Subcutaneous Deferoxamine in Patients with Thalassemia Major

We examined the efficacy of long-term subcutaneous deferoxamine therapy in the prevention of iron-related cardiac disease in patients with thalassemia major who began treatment after the age of 10 years. Of 36 such patients without preexisting cardiac disease, 19 did not comply with the program of chelation therapy. Over the course of treatment (1977 to 1983) serum ferritin and aspartate aminotransferase levels fell in the compliant group, from mean values (+/- S.D.) of 4765 +/- 2610 to 2950 +/- 1850 ng per milliliter and 58.1 +/- 22 IU to 30 +/- 20 IU per liter, respectively (P less than 0.05), but rose in the noncompliant group, from 5000 +/- 2316 to 6040 +/- 2550 ng per milliliter and 56.6 +/- 20 to 90 +/- 35 IU per liter, respectively. Only one patient in the compliant group acquired cardiac disease and died of fulminant congestive heart failure. In contrast, 12 noncompliant patients acquired cardiac disease, and 7 died. In addition, the mean age of the compliant population (18.9 +/- 4.5 years) now approaches the mean age of acquisition of cardiac disease in the noncompliant group (19 +/- 4.3). These data demonstrate that compliance with treatment with deferoxamine may protect patients from cardiac disease induced by iron overload.

Complete Correction of the Wiskott-Aldrich Syndrome by Allogeneic Bone-Marrow Transplantation

Two patients with the Wiskott-Aldrich syndrome had complete donor lymphoid and hematopoietic engraftment after successful allogeneic bone-marrow transplantation. One patient had had only a temporary donor T-lymphocyte graft after a previous transplantation, for which he had been prepared with cytarabine and cyclophosphamide; the patients own T lymphocytes returned six months later. A repeat transplant, for which the patient was prepared with anti-human thymocyte serum, total-body irradiation and procarbazine, resulted in complete donor engraftment. The second patient underwent a successful transplantation after similar preparation, except that procarbazine was omitted. At 11 and five months after transplantation both had normal hematopoiesis and no evidence of graft-versus-host disease. This treatment of the Wiskott-Aldrich syndrome may be a model for the correction of other genetically determined immune and hematologic bone-marrow disorders.