Robert J. Mamlok

Suppression of graft-versus-host reaction in severe combined immunodeficiency with maternal-fetal T cell engraftment

Simultaneous engraftment of maternal T cells and T cells from unrelated transfusion donor in an infant with severe combined immunodeficiency disease (SCID) was identified by HLA typing blood lymphocytes of the patient, her triplet siblings, parents, and the platelet donor from whom the patient received nonirradiated platelet transfusion. T cell grafts from both the mother and platelet donor were stable for several months, but the graft-versus-host reactions (GvHR) remained mild and immune function was deficient. We hypothesize that immunosuppressive effects of a maternal-fetal GvHR may have modified the expected lethal GvHR from platelet donors T cells.

Glucose-6-phosphate dehydrogenase Beaumont: a new variant with severe enzyme deficiency and chronic nonspherocytic hemolytic anemia.

Studies were carried out on erythrocytes and fibroblasts from a 3-year-old white male with severe glucose-6-phosphate dehydrogenase (G6PD) deficiency and chronic non-spherocytic hemolytic anemia. Red blood cell G6PD activity was less than 0.02% of normal values. Since the childs fibroblasts had 2-4% of normal enzymic activity, they were utilized as a source of enzyme for kinetic studies. The G6PD demonstrated marked heat lability, a normal Km value for glucose-6-phosphate (56 mumol/l), a nearly normal pH-activity curve, and increased utilization of 2-deoxyglucose-6-phosphate (76% of the rate with glucose-6-phosphate). These studies clearly indicate that this is a new molecular variant (G6PD Beaumont).

189 METABOLIC ACIDOSIS, HYPERGLYCEMIA, AND KETONURIA IN CARBAMAZEPINE OVERDOSE

Certain drugs may produce hyperglycemia by decreasing pancreatic secretion of insulin. We report a case of accidental carbamazepine overdose in a previously healthy three year old black male who presented in an unconscious state without seizures with an arterial pH of 7.28, serum glucose of 210 mg/dl, and urine glucose and ketones of 3+ and 2+, respectively. Arterial blood gases showed a pure metabolic acidosis. A diagnosis of diabetic ketoacidosis was made; the patient was given insulin, sodium bicarbonate, and intravenous hydration. Subsequent history revealed that the patient ingested an unknown amount of carbamazepine. A toxic serum carbamazepine level of 22 mcg/ml (therapeutic = 6 to 10) was found. The patient was treated with activated charcoal and general supportive care. Complete symptomatic recovery occurred by the end of 48 hours and follow up laboratory studies failed to show any evidence of hyperglycemia, ketonuria, or glycosuria.This case demonstrates a previously unreported manifestation of carbamazepine overdose in a child, i.e., metabolic acidosis, hyperglycemia and ketonuria. Carbamazepine in high dose is known to produce hyperglycemia in rats possibly by decreasing the sodium influx needed for insulin secretion (Pharmacology 24:123, 1982). We conclude that metabolic acidosis due to carbamazepine overdose should be considered in the differential diagnosis of altered metabolic states and drug overdose.

IMMUNE HEMOLYTIC ANEMIA AFTER BONE MARROW TRANSPLANTATION FOR SEVERE COMBINED IMMUNODEFICIENCY

Bone marrow transplantation (BMT) has occasionally been complicated by the development of hemolytic anemia from specific alloantibodies to either ABO or Rh antigens. We report a case of post-BMT hemolytic anemia in severe combined immunodeficiency (SCID) due to IgG antibodies that agglutinate all red blood cells (RBC) in a broad panel of allotypes.A 15 month old female with recurrent respiratory distress and oral candidiasis had panhypogammaglobulinemia, decreased T-lymphooytes (312/mm3) and mitogen responsiveness. A diagnosis of SCID prompted transplantation of unfractionated bone marrow from her HLA identical, MLC non-reactive mother without prior ablative therapy or post-transplant graft-vs-host disease (GvHD) prophylaxis. Bone marrow engraftment proceeded rapidly without evidence of GvHD. Eight weeks after BMT her hemoglobin acutely fell to 3.4g/dl with 42% reticulocytes. Direct and indirect antiglobulin tests were positive. Although the donor (A−) and recipient (A+) differed at two Rh loci, the antibody specificity was not restricted to the Rh allotypes.This appears to be the first report of post-BMT immune hemolytic anemia in SCID due to an antibody of broad rather than allospecificity. Ongoing studies may provide a better understanding of the mechanisms of autoantibody production in immune hemolytic anemia.

EVIDENCE FOR MODULATION OF GRAFT-VS-HOST DISEASE BY INTRAUTERINE ENGRAFTED MATERNAL T LYMPHOCYTES

A four month old dizygotic triplet with pseudomonas sepsis and disseminated intravascular coagulopathy necessitating platelet tranfusions was subsequently found to have severe combined immunodeficiency (SCID) with thymic dysplasia and mild cutaneous graft-vs-host disease (GvHD). T lymphocytes from the mother and both platelet donors but not from the triplets were identified in the patients blood by HLA typing. Non-T lymphocytes displayed the same maternal and paternal haplotypes as the other triplet siblings and absorption of lymphocytotoxic HLA antibodies by the patients platelets confirmed the patients HLA genotype.GvHD resolved during ablative therapy with anti-thymocyte globulin and cyclophosphamide and did not recur following bone marrow transplantation (BMT) from an HLA identical triplet. One month after BMT, T lymphocytes from one platelet donor, but not from the mother, were still found in the patients blood.Since GvHD from non-irradiated blood transfusions in SCID patients is fatal without treatment, we hypothesize that intrauterine engraftment of maternal cells and/or mild GvH reaction induced by these cells suppressed the GvHD from the platelet donors lymphocytes. An exacerbation of the GvHD after maternal cells disappeared may have been prevented by immune function from the BMT. Thus, intrauterine engraftment of maternal T lymphocytes, which usually causes limited GvHD, may modulate the GvHD due to postnatally transplanted T lymphocyes.

NEUTROPENIA AND DEFECTIVE CHEMOTAXIS ASSOCIATED WITH BINUCLEAR, TETRAPLOID MYELOID-MONOCYTIC LEUKOCYTES

A 13 year-old male presented with recurrent cellulitis and osteomyelitis and persistent neutropenia (blood neutrophils count of 100/mm3). The bone marrow was normal except for two nuclei in the majority of metamyelocytes and bands and in all segmented neutrophils. No binucleated myeloblasts, myelocytes or other cell types were found. Granulocyte-monocyte colonies cultured from bone marrow had single nucleated and binucleated band forms and metamyelocytes, but no binucleated myelocytes or myeloblasts. Cytogenetic studies of bone marrow cells showed that the single nucleated cells were 46XY, while the binuclear cells were predominantly 92XXYY.Chemotaxis of myeloid bone marrow cells was examined by a subagarose method. The patients cells showed no directed movement towards zymogan activated serum (ZAS) or a synthetic peptide, F-Met-Phe, whereas directed and random movement of myeloid bone marrow cells from adult controls was detected (F-met-Phe, 13.2 u/mm and 9.5 u/min; ZAS 22 u/min and 11.7 u/min).These findings suggest that defective egress of binucleated tetraploid neutrophils from the bone marrow resulted in chronic neutropenia. Further studies on the cytoplasmic architecture of these cells may help define a link between the failure of cytoplasmic splitting and the impaired chemotaxis of myeloid cells.

923 GLUCOSE-6-PHOSPHATE DEHYDROGENASE DEFICIENCY, NEUTROPHIL DYSFUNCTION AND CHROMOBACTERIUM VIOLACEUM SEPSIS

A three year old white male with Class I glucose-6-phosphate dehydrogenase (G-6-PD) deficiency developed fever and lethargy. In spite of antibiotics, he developed septic shock and died twelve hours later. Blood and post-mortem liver cultures grew Chromobacterium violaceum. Molecular, kinetic and functional studies were carried out on erythrocytes (RBCs), leukocytes (PMNs) and fibroblasts of his identical twin and mother.Chemiluminescence was profoundly abnormal in the twin.G-6-PD isolated from the twins fibroblasts demonstrated heat lability (27% of initial activity), normal G-6-P Km (56μM) and pH curve, and increased utilization of 2-d-G6P (76% of G-6-P rate); suggesting a new molecular variant (G-6-PD Beaumont).This is the first reported lethal infection in a child with neutrophil dysfunction due to PMN G-6-PD deficiency. This enzyme defect, like classic chronic granulomatous disease, may cause unique susceptibility to Chromobacterium violaceum.