Recurrent immune cytopenias in two patients with DiGeorge/velocardiofacial syndrome.

We describe two patients with clinical and cytogenetic findings consistent with DiGeorge/velocardiofacial syndrome who had recurrent cytopenias at presentation. Our observations suggest that recurrent cytopenias may be part of the clinical spectrum of deletion 22q11.2. We also suggest that the diagnosis of DG/VCF syndrome be considered in patients with unexplained recurrent immune cytopenias in association with cardiac lesions, subtle craniofacial dysmorphisms, and/or learning or behavioral impairments.

Two new EPO receptor mutations: truncated EPO receptors are most frequently associated with primary familial and congenital polycythemias.

Primary polycythemias are caused by an acquired or inborn mutation affecting hematopoietic/erythroid progenitors that results in an abnormal response to hematopoietic cytokines. Primary familial and congenital polycythemia (PFCP; also known as familial erythrocytosis) is characterized by elevated red blood cell mass, low serum erythropoietin (EPO) level, normal oxygen affinity of hemoglobin, and typically autosomal dominant inheritance. In this study we screened for mutations in the cytoplasmic domain of the EPO receptor (EPOR; exons 7 and 8 of the EPOR gene) in 27 unrelated subjects with primary or unidentified polycythemia. Two new EPOR mutations were found, which lead to truncation of the EPOR similarly to previously described mutations in PFCP subjects. The first is a 7-bp deletion (del5985-5991) found in a Caucasian family from Ohio. The second mutation (5967insT) was found in a Caucasian family from the Czech Republic. In both cases the EPO dose responses of the erythroid progenitors of the affected subjects were examined to confirm the diagnosis of PFCP. In one of these families, the in vitro behavior of erythroid progenitors in serum-containing cultures without the addition of EPO mimicked the behavior of polycythemia vera progenitors; however, we show that antibodies against either EPO or the EPOR distinguish the in vitro growth abnormality of polycythemia vera erythroid progenitors from that seen in this particular PFCP family. We conclude that PFCP is a disorder that appears to be associated in some families with EPOR mutations. So far, most of the described EPOR mutations (6 out of 8) associated with PFCP result in an absence of the C-terminal negative regulatory domain of the receptor.

Does sleep-disordered breathing contribute to the clinical severity of sickle cell anemia?

PURPOSE: This research was undertaken to determine whether obstructive sleep apnea (OSA) and/or nocturnal hemoglobin desaturations contribute to the clinical severity of sickle cell anemia (SS). PATIENTS AND METHODS: Eleven patients with severe SS (group S), defined by two or more hospitalizations in the previous year for painful crises, were compared to eight patients with mild SS (group M) who had not been hospitalized for painful crises in the past year. An additional cohort of nine patients with SS who had been referred to the Sleep Disorders Center because of a clinical suspicion of OSA were studied (group R). All patients underwent full overnight polysomnography and performed standard pulmonary function tests. RESULTS: There were no significant differences in the respiratory disturbance index (RDI; apneas plus hypopneas per hour of sleep) or hemoglobin desaturation between the mild and severe groups, and neither RDI nor hemoglobin saturation predicted the number of painful crises. Despite a suggestive clinical presentation, only 44% of the patients in group R had OSA confirmed polysomnographically. CONCLUSIONS: In this preliminary study, unsuspected nocturnal cardiopulmonary disease and hemoglobin desaturation did not explain the variability in the severity of SS disease. However, OSA can occur in patients with SS, and when clinically suspected, the diagnosis should be confirmed with overnight polysomnography so that appropriate treatment can be instituted.

Cyclosporin A treatment for Diamond-Blackfan anemia.

Diamond-Blackfan anemia (DBA) is characterized by a variable response to corticosteroid therapy. Patients poorly responsive to acceptable doses of steroid treatment require long-term transfusion therapy. We have treated three patients with DBA with the immunosuppressive agent cyclosporin A with limited success. Patients 1 (DS) and 2 (LS), half-siblings, were 13 and 9 years old, respectively, and remained transfusion independent for many years on steroid therapy. Both patients manifest steroid-associated growth failure and osteopenia, with resultant orthopedic complications. Oral cyclosporin therapy sufficient to achieve trough serum levels of 100-200 ng/ml was associated with a brisk 50-100% increase in hematocrit within 1 month of initiation of treatment and allowed for a gradual tapering of prednisone dose to approximately 20% of prior established maintenance dose. After 7-8 months, both patients developed progressive decline in hematocrit level requiring increased prednisone dose and, ultimately, transfusion support. Patient 3 (RD), a 5-year-old child with steroid refractory, transfusion-dependent DBA, was entirely unresponsive to cyclosporin therapy. No cyclosporin-associated toxicity occurred. Our observations indicated that cyclosporin A can transiently ameliorate the hematologic course of some patients with DBA. Further studies are in order to determine its mechanism of action and potential clinical utility in patients unresponsive to acceptable doses of steroid.

Spontaneously regressing adrenocortical carcinoma in a newborn. A case report with DNA ploidy analysis.

Adrenal cortical carcinoma is an uncommon neoplasm in children. Only a handful of congenital adrenal cortical carcinoma cases have been described. A newborn who had metastatic adrenal cortical carcinoma (skin metastases and cerebral lesions) is described. This patient underwent surgical resection of the right adrenal primary, but no further treatment was given. Hemihypertrophy developed in this patient by 2 months of age, and at 4 months of age spontaneous regression of all skin nodules and central nervous system (CNS) lesions was observed. Follow-up at 1 year shows the patient to be alive, well, and disease-free. Evaluation of the tumor included DNA ploidy analysis that showed the tumor to be polyploid, a pattern recently associated with nonmetastasizing adrenal cortical neoplasm. The observation of apparent metastatic disease that regressed spontaneously highlights the prognostic value of DNA ploidy analysis and raises the possibility of an adrenal tumor with properties similar to those of Stage IV-S neuroblastoma.

Reduction of contact factors in sickle cell disease.

Surface-mediated reactions of clotting were compared in 21 black children with homozygous sickle cell disease, 12 age-matched controls, and 15 adults. Both the coagulant and antigen titers of Hageman factor (factor XII) were decreased in asymptomatic patients compared with those in the control groups. These findings were associated with slight but significant reductions in the plasma titers of prekallikrein and high molecular weight kininogen. A further decrease from the initially low titers of these contact factors was observed during vaso-occlusive crises. Additionally, we observed a disparate relationship between Hageman factor coagulant activity and its antigen titers. These data provide evidence for reduction of the contact factors in patients with homozygous sickle cell disease.

Molecular analysis of the beta-thalassemia phenotype associated with inheritance of hemoglobin E (alpha 2 beta2(26)Glu leads to Lys).

Inheritance of the gene for betaE-globin is associated with hypochromia and microcytosis, reminiscent of typical heterozygous beta-thalassemia. Patients with hemoglobin (Hb)E-beta-thalassemia exhibit clinical phenotypes of severe beta-thalassemia, a circumstance not encountered in other compound heterozygous states for structural beta-chain mutations and beta-thalassemia. We have analyzed the kinetics of globin synthesis and the levels of globin messenger (m) RNA accumulation in patients with Hb E-beta-thalassemia and Hb E trait. The initial rate of beta-globin synthesis (betaE/alpha=0.20-0.34) was less than expected on the basis of gene dosage, or comparable studies of other compound heterozygous states for beta-thalassemia and structurally abnormal beta-chains. betaE-globin synthesis was not only reduced during short-term incubations (1-5 min), but also remained relatively unchanged during long-term pulse or chase incubations up to 5h. Analysis of globin mRNA by cell-free translation and molecular hybridization confirmed that the unexpectedly low levels of betaE-globin synthesis were associated with comparable reduction in the levels of beta-globin mRNA. In Hb E-beta-thalassemia the betaA + betaE (alpha globin nRNA ratio observed were substantially lower than those obtained from reticulocytes of patients with heterozygous beta-thalassemia, or Hb S-betaO-thalassemia, while in Hb E trait, the betaA + betaE/alpha mRNA ratio was in the ranged observed for beta-thalassemia trait. The betaE-globin gene specifies reduced accumulation of betaE-globin mRNA, a property characteristic of other forms of beta-thalassemia. The beta-thalassemia phenotype associated with inheritance of Hb E is thus determined at the level of beta-globin mRNA metabolism.

Spontaneously acquired Factor IX inhibitors in childhood.

Two previously healthy children, ages 8 months and 35 months, developed spontaneous inhibitors to Factor IX. Brief illnesses of presumed viral origin preceeded hemorrhagic symptoms in both children. Cutaneous ecchymoses and traumatic soft tissue hemorrhage were the predominant clinical features in each case. Bleeding symptoms persisted for less than 3 days and laboratory evidence of Factor IX inhibition resolved within 3 weeks. One child required treatment with fresh frozen plasma and packed red blood cell transfusions. The other child received corticosteroid therapy. Given the transient nature of acquired Factor IX inhibitors in the nonhemophilic child, a conservative approach toward therapy is recommended unless life-threatening complications supervene.

Hematology of beta-thalassemia trait--age-related developmental aspects and intrafamilial correlations.

Beta-thalassemia trait is a frequent cause of microcytic anemia in Mediterranean children. Because striking age-related changes occur in hemoglobin and mean corpuscular volume during childhood, we assessed developmental hematologic characteristics of 132 patients less than or equal to 18 years of age with beta-thalassemia trait. Thirty-nine kindred were studied to examine intrafamilial correlations of hematologic abnormalities. Patients with beta-thalassemia trait demonstrated Hgb values about 2 gm/dl below normal standards, with a progressive rise with age paralleling normal trends. Thalassemic MCV values showed a far greater deviation from normal than Hgb levels. In contrast to normal developmental trends which show a sharp increase in the first five years of life, the MCV in thalassemia trait showed no age-related increase prior to adolescence. No age-related changes in hemoglobin A2 levels were noted. Kindred studies demonstrate a correlation of the degree of anemia, microcytosis, and elevated hemoglobin A2 levels in affected family members (r = 0.318 P < 0.004, r = 0.525 P < 0.001, r = 0.416 P < 0.0015, respectively). Our findings support the use of electronically determined MCV values as an initial screening procedure for children with beta-thalassemia trait. Values of < 70 fl prior to adolescence and < 75 fl during adolescence were present in nearly all thalassemic subjects. Intrafamilial correlations of Hgb, MCV, and hemoglobin A2 levels suggest that these characteristics are genetically determined.

Embryonic-fetal erythroid characteristics of a human leukemic cell line.

We have studied a number of cell surface, enzyme, and protein markers in the human leukemic K562 cell line. We have confirmed previous observations that these cells accumulate human embryonic hemoglobins after exposure to hemin. In addition, our results demonstrated that these cells possess in the "ininduced" state i surface antigen, lactate dehydrogenase isoenzymes characteristic of embryonic or fetal erythroid cells, fetal and embryonic globin chains, and globin mRNAs. The levels if i antigen, embryonic globin chains, and embryonic globin mRNA increased substantially after exposure of the cells to hemin in suspension culture. In contrast, K562 cells lacked several surface, enzymatic, and functional properties typical of granulocytes, lymphocytes, monocytes, or adult erythroblasts, including HLA surface antigens, surface immunoglobulins, sheep erythrocyte rosetting, phagocytosis, terminal deoxynucleotidyl transferase, carbonic anhydrase, ABO and Rh blood groups, and adult hemoglobins. The K562 cell line therefore exhibits phenotypic properties of embryonic erythroid progenitor cells and a quantitative increase in the expression of some of these properties can be achieved by exposure of the cells to hemin.