Different impacts of alleles alphaLEPRA and alphaLELY as assessed versus a novel, virtually null allele of the SPTA1 gene in trans.

The family of two siblings with severe hereditary spherocytosis was investigated. The decrease was evident on both the alpha- and the beta-chains. The parents were haematologically normal. The mother was heterozygous for the low-expression polymorphic allele alphaLEPRA. The father was heterozygous for a novel combination in which one allele showed the alpha-spectrin low expression polymorphic allele alphaLELY, while his other allele showed the alphaLELY polymorphism in cis with a G-->A substitution, named Bicêtre, found at the extreme 3' end of exon 51. This combination was designated alpha(LELY-Bicêtre). The children were compound heterozygotes for alleles alphaLEPRA and alpha(LELY-Bicêtre). Reverse transcription polymerase chain reaction detected only trace amounts of the mRNA coding for alpha(LELY-Bicêtre). Mutation is therefore an essentially null mutation with no functional protein product. The lack of disease in the alphaLELY/(LELY-Bicêtre) father compared with the marked haemolysis in the alphaLEPRA/alpha(LELY-Bicêtre) children showed that expression of allele alphaLELY is not low enough to expose null alpha-spectrin alleles on the other chromosome. Quantitative estimations from these findings suggest that, to evoke spherocytosis, it is necessary that alpha-spectrin expression must be reduced to less than 25% of normal, while a reduction to 8% is sufficient.

Misdiagnosis of chronic thrombocytopenia in childhood.

PURPOSE: Children ultimately diagnosed with nonimmune chronic thrombocytopenia are often referred to pediatric hematology clinics with a provisional diagnosis of autoimmune thrombocytopenic purpura (AITP). The authors' aim was to establish in these patients the features characterizing the mechanism of thrombocytopenia. PATIENTS AND METHODS: The authors performed a retrospective review of the case records of seven children (three boys and four girls, aged 5 months to 7 years) with misdiagnosed chronic AITP referred to a single pediatric hematology center between 1990 and 2000. RESULTS: In the seven children, the suspected diagnosis on referral was AITP and the final diagnosis was inherited thrombocytopenia. Abnormalities of platelets and/or leukocyte morphology were present in all of them. Other features suggestive of inherited thrombocytopenia included a history of familial thrombocytopenia (2/7), failure of steroids and/or intravenous immunoglobulins to raise the platelet count to normal levels (5/7), and moderate increase of Indium-111 platelet turnover in the two patients tested. Platelet-associated IgG (PaIgG) was above the normal threshold in the four children tested; the direct monoclonal antibody immobilization of platelet antigens (MAIPA) test was negative in the four children tested and the serum test was positive in two boys. Bone marrow examination revealed either a normal (4/7) or an elevated (3/7) number of megakaryocytes. CONCLUSIONS: Family history and blood cell morphology analysis in experienced hands are the first steps in discriminating AITP from inherited thrombocytopenia in children with isolated chronic thrombocytopenia. In contrast, bone marrow examination and search for specific autoantibodies using the MAIPA test are of little help. An isotopic platelet life span study, when available, should be performed before considering splenectomy to exclude the diagnosis of inherited thrombocytopenia, especially when steroids and/or IgG IV administration failed to raise the platelet count.

Dyserythropoiesis associated with a fas-deficient condition in childhood.

Defective lymphocyte apoptosis caused by mutations of the Fas gene can result in an autoimmune lymphoproliferative syndrome (ALPS) in humans. We report two cases of dyserythropoiesis associated with a Fas-deficient condition in childhood. In both cases, dyserythropoiesis predominated on the more mature erythroblasts, and was associated with a lymphoproliferative syndrome as well as with haemolytic anaemia, hypergammaglobulinaemia and the expansion of an unusual population of CD4- CD8- T cells that express the alpha/beta T-cell receptor. The regression of dyserythropoiesis under steroid therapy suggested that it resulted from an autoimmune mechanism, itself secondary to the lymphocyte Fas apoptosis deficiency. Fas-defective apoptosis may be a new aetiology for childhood dyserythropoiesis.

Pregnancy-associated thrombocytopenia revisited: assessment and follow-up of 50 cases.

Thrombocytopenia detected during pregnancy addresses the issue of its mechanism and of the possible occurrence of neonatal thrombocytopenia. To further investigate these issues, 50 women referred to us because of thrombocytopenia detected during pregnancy (platelet count, <150 x 10(9)/L), were extensively studied, as well as their offspring. Among these thrombocytopenic women, we used the threshold of 70 x 10(9)/L to differentiate between mild and severe thrombocytopenia. Whatever the severity of thrombocytopenia, we found biological features of an autoimmune disorder in 48% of the women, and chronic thrombocytopenia in 55%. A familial thrombocytopenia was evidenced in 1 case. These 50 women gave birth to 63 neonates, among whom 24 were thrombocytopenic, either at birth or during the first week of life. Neonatal thrombocytopenia could only be predicted in multiparous women, on the basis of previous neonatal thrombocytopenia in older siblings, and/or when maternal platelet life span study, performed before pregnancy, had evidenced an autoimmune thrombocytopenia (AITP)-like profile. These results suggest that, in case of pregnancy-associated thrombocytopenia, familial and immunological studies, combined with postdelivery iterative platelet counts, should be performed to properly characterize the thrombocytopenia. Moreover, the platelet count of the neonate should be carefully assessed at birth and during the following days, a platelet life span study should be performed after delivery in the mother, because these two parameters are likely to bring valuable information regarding the forthcoming pregnancies and the risk of neonatal thrombocytopenia.

Erythrocyte ferritin in human neonates: maternofetal iron kinetics revisited.

Serum and erythrocyte ferritin concentrations were measured in 369 healthy term neonates and their mothers, with a view to understanding maternofetal iron kinetics. Erythrocyte ferritin concentrations in the neonates were on average 100 times higher than maternal values, while those of serum ferritin were about 10 times higher. Maternal and fetal iron status were correlated in the overall study population. Serum and erythrocyte ferritin values were also correlated with each other in both the mothers and neonates. To study the influence of iron status on these conditions, we formed three groups of mother-child pairs of equal size, based on maternal iron status (serum ferritin). The correlations found in the overall population were not always present in each subgroup. In the infants born to mothers with adequate tissue iron reserves (serum ferritin > 12 micrograms/I), a statistical link was found between serum and erythrocyte ferritin levels. When the mothers had optimal iron status (serum ferritin > or = 22 micrograms/I), there was a correlation between the neonatal and maternal erythrocyte ferritin levels. No such links were found when the mothers had low tissue iron stores (serum ferritin < 12 mg/I). These data point to special iron kinetics during fetal life and the influence of maternal iron status.

[Role of iron deficiency in anemia in pregnant women in Mali]. / Place de la carence martiale dans l'anémie de la femme enceinte au Mali.

The epidemiological characteristics of iron deficiency anemia after radioimmunoassay of serum and erythrocyte ferritin were evaluated in 209 Malian women at the time of delivery in a maternity unit in Bamako, Mali. The incidence of iron deficiency anemia was high (36.8%). This incidence did not reflect socio-economic status, nor even any particular obstetric history, but was significantly higher in younger mothers (aged under 26). The severity of anemia was such that 2.4% of women would require a blood transfusion post-partum. It looks therefore desirable, in Mali, to screen routinely and to ensure the prevention of iron deficiency in adolescent girls and to include, in the prevention of anemia of pregnant women, routine iron supplements from the beginning of pregnancy.

[Erythrocyte indices and iron stores in cord blood]. / Paramètres érythrocytaires et réserves en fer dans le sang du cordon.

BACKGROUND: Reevaluation of normal red cell values in the cord blood is necessary since these values were established before the use of automated analysers and the introduction of iron supplementation during pregnancy. POPULATION AND METHODS: Cord blood samples from all healthy babies from Monday to Friday for 2 months have been analysed for red cell count and red cell indices, hemoglobin concentration, hemoglobin electrophoresis, serum and erythrocyte ferritin concentration. The results were compared for the mothers to age, parity and duration of iron supplementation and for the neonates to gestational age and birth weight. RESULTS: One hundred and fifty-nine neonates were studied; 87% of their 154 mothers had been given iron during pregnancy. Mean red cell indices were found to be slightly below those of previous reports in the literature. They were associated with mean ferritin concentrations of 135 micrograms/l and 348 ag/cell for plasma and erythrocytic ferritin, respectively. CONCLUSION: There were no correlations between red cell indices and ferritin values in such an iron-repleted population.

Neonatal thrombocytopenia and hidden maternal autoimmunity.

Severe transient thrombocytopenia was observed in 17 newborns delivered by 11 mothers who persistently exhibited normal platelet counts and had no previous immunological or platelet disorder. Maternofetal alloimmunization as well as other causes for fetal thrombocytopenia were ruled out. A specific circulating autoantibody directed against the platelet glycoprotein Ib/IX complex was found in 10/11 mothers and in 3/4 offspring. After delivery, maternal compensated thrombocytolysis and/or hypersplenism were demonstrated by 111Indium labelled platelet studies in 10/11 women. The association of a compensated thrombocytolysis and of a specific maternal circulating antiplatelet autoantibody makes likely the diagnosis of mild maternal chronic autoimmune thrombocytopenic purpura (AITP) only expressed by the fetal or neonatal thrombocytopenia. The finding of anti-IbIX autoantibody in control women who gave birth to neonates without thrombocytopenia raises the question of the incidence and clinical significance of such antibodies which could be natural autoantibodies as well as associated with compensated thrombocytolysis or with overt immune thrombocytopenia. The cause of the discrepancy between the fetal and maternal platelet status, which could be explained by a different conformational state of fetal as compared to adult GP Ib/IX, deserves further investigation.

HBV infection in pediatric liver transplantation.

When hepatitis B virus (HBV) infection precedes orthotopic liver transplantation (OLT), an important issue is to avoid post-OLT HBV infection of the transplanted liver. When HBV infection is found after OLT, the main objective is to prevent the complication of cirrhosis. A study of HBV infection in 162 liver-transplanted children followed at Hôpital de Bicêtre is presented here. One hundred forty-one of these children were completely vaccinated against HBV; 89% of them still disposed of protective titers of serum antibodies to hepatitis B surface antigen (anti-HBs) (> 10 IU/L) 6-60 months after OLT. Four children had a HBV-associated liver disease that required OLT. In these children a passive immunoprophylaxis maintaining serum anti-HBs levels > 100 IU/L allowed three of them to remain free of serum hepatitis B surface antigen (HBsAg) and HBV-DNA during follow-up at 10, 20, and 36 months. Four other children have been found to be HBsAg+ after OLT, but it was not clear whether the source of HBV was a reactivation or a de novo infection. Low doses of cyclosporin and prednisone were administered, in order to avoid the complications of HBV infection. Liver needle biopsies in three of these patients 37, 42, and 46 months after OLT showed a moderate chronic active hepatitis and mild fibrosis. Immunostaining for HBs and hepatitis B core (HBc) antigens indicated active viral replication.(ABSTRACT TRUNCATED AT 250 WORDS)

Initial assessment of the beneficial effect of partial splenectomy in hereditary spherocytosis.

Clinical manifestations of hereditary spherocytosis (HS), the most common red blood cell (RBC) membrane disorder, can be abrogated or markedly reduced by splenectomy. However, concerns regarding risks from overwhelming infections after splenectomy have restricted its use, especially in children. This study was designed to determine if partial splenectomy can decrease the hemolytic rate while maintaining phagocytic function of the spleen. Partial splenectomy was performed in 11 children (age 2 to 13) with HS. The effect on hemolytic rate was assessed by comparing the presurgical and postsurgical values for hemoglobin, reticulocyte number, and RBC life span. The residual splenic phagocytic function was assessed using technetium 99m scans and by enumerating the percentage of pitted RBCs in circulation. There were no complications from the surgical procedure in any of the 11 individuals. Following partial splenectomy, hemoglobin increased on the average by 3 g/dL, reticulocyte count decreased by 300 x 10(6)/L, and RBC life span was substantially prolonged. Normal technetium uptake was noted in the splenic remnant and the percentage of pitted RBCs was in the normal range. Partial splenectomy is effective in decreasing the hemolytic rate while maintaining residual splenic phagocytic function of the spleen in HS. We conclude that the use of this procedure as treatment for RBC membrane disorders warrants consideration, especially in infants under 5 years of age who need frequent transfusions.

[Regressive myelodysplastic syndromes in children. Committee on Childhood Myelodysplasia of the Society of Pediatric Hematology and Immunology]. / Myélodysplasies régressives de l'enfant. Groupe de Travail sur les Myélodysplasies de l'Enfant de la Société d'Hématologie et d'Immunologie Pédiatrique (SHIP).

BACKGROUND: As in adults, myelodysplastic syndromes in children are often preleukemic and their spontaneous remission is exceptional. CASE REPORTS: Case 1. A girl, aged 8 years, developed pancytopenia with macrocytic anemia. The myelogram and bone marrow biopsy showed dyserythropoiesis with macroblastosis, but without sideroblasts. The chromosome configuration was normal and the negative results of other investigations led to the diagnosis of refractory anemia without any known cause. Bone marrow transplantation was considered, but a spontaneous remission intervened and has persisted for 3 years. Case 2. A girl, aged 5 years, was investigated for worsening of a macrocytic anemia that had been present for 3 years, without changes of granulocytes and platelets. The myelogram showed dyserythropoiesis with megaloblastosis and sideroblasts. No known cause could be identified. As for the preceding patient, a spontaneous remission occurred, and has persisted for 3 years. Case 3. A girl, aged 5 months, developed pancytopenia. The myelogram showed dys-megakaryocytopoiesis. All hematologic data spontaneously normalized after 1 year, and have remained so 1 year later. CONCLUSION: The spontaneous remission, that has occurred in our 3 patients, has been reported in one only adult. This possibility precludes considering all the myelodysplastic syndrome in children as preleukemic, and suggests that bone marrow transplantation is not urgent in these situations.

Met 358 to Arg mutation of alpha 1-antitrypsin associated with protein C deficiency in a patient with mild bleeding tendency.

The molecular defect responsible for a dramatic prolongation of all standard clotting tests discovered in a 15-yr-old boy has been identified. Initial investigations revealed the presence of an activated Factor X (Factor Xa) and thrombin inhibitor which copurified with alpha 1-antitrypsin (alpha 1-AT), thereby suggesting the occurrence of an alpha 1-AT variant similar to alpha 1-AT Pittsburgh. This was confirmed by dot-blot analysis and direct sequencing after amplification by the polymerase chain reaction. A G to T transition at nucleotide 10038 results in the substitution of Met to an Arg, converting alpha 1-AT into an Arg-Ser protease inhibitor (serpin) that inhibited thrombin and Factor Xa more effectively than antithrombin III. Surprisingly, there was no bleeding history in the proband. The common mutation Z, which may explain a reduced expression of the allele bearing the Arg 358 Met mutation, was not observed in the propositus' DNA. To exclude the presence of another mutation, the coding regions and intron/exon junctions were sequenced. No other mutation was found. Recently, the patient experienced his first hemorrhagic episode at the age of 17. The level of the abnormal inhibitor had increased twofold 2 mo before. The large decrease in protein C concentration may account for the mild bleeding tendency in this case, despite the presence of the alpha 1-AT Pittsburgh mutation. An abnormal protein C pattern was observed in patient's plasma, suggesting that the circulating deficiency might be due to a deleterious effect of the abnormal inhibitor on both intracellular processing and catabolism of protein C.

MR imaging of hemophilic arthropathy of the knee: classification and evolution of the subchondral cysts.

Magnetic resonance imaging was performed to assess the subchondral bone of the knee in 64 patients with severe hemophilia A. Using this method, subchondral cysts could be detected and evaluated. We separated the cysts into four classes (LL, LH, HH, C) depending on their signal intensities on T1- and T2-weighted images. Follow-up studies, performed on 25 patients during a period of 10-30 mo after the initial examination, suggest that these four classes of cysts correspond to four successive stages. Morphological changes within a class of cysts were also observed. Although histological confirmation was not possible, this study demonstrated that magnetic resonance imaging allows a better understanding of the pathophysiology and the natural evolution of the subchondral cysts in hemophilic arthropathy.

Reevaluation of the utility of mean cell hemoglobin (MCH) screening in infants for iron deficiency.

Iron deficiency (ID) at the stage of latent deficiency (LID) or frank anemia (IDA) is still common in pediatric practice. We have assessed the prevalence of LID and IDA in an infant population with an age range of 9-11 months, in Paris. Red cell indices, hemoglobin level, serum iron, transferrin saturation and serum ferritin levels were assayed. There was considerable prevalence of ID as 82% of the children exhibited low levels in one of the above parameters. We found low mean cell hemoglobin (MCH) to be predictive of LID in one third of cases. Since MCH value is routinely available to the physician, it appears that a close examination of this red cell index should allow for the diagnosis of ID in a large number of children at risk, without the need to resort to more elaborate and expensive laboratory tests.

[Wilson's disease with liver copper in normal concentration]. / Maladie de Wilson avec concentration hépatique en cuivre normale.

The cases of 2 children with Wilson's disease revealed by persistent hypertransaminasemia are reported. Blood ceruloplasmin concentration was low but the liver content of copper was lower than usually seen in presymptomatic forms of the disease. The apparently low liver copper concentration could be explained by an unusually important steatosis.

In vitro effect of duodenal juice on R binders cobalamin complexes in subjects with pancreatic insufficiency: correlation with cobalamin absorption.

Absorption of cobalamin free or bound to chicken serum was assessed in nine patients with pancreatic insufficiency. Simultaneously the in vitro effect of duodenal juice collected from six patients and seven controls was tested on labelled cobalamin complexed to chicken serum or to R salivary binder. Malabsorption of free cobalamin was observed in one of nine patients and in four of nine patients when cobalamin was administered bound to chicken serum. The in vitro effect of duodenal juice on cobalamin complexed to chicken serum or to R salivary binder was studied: the percentage of free cobalamin released was significantly decreased in pancreatic insufficiency compared with controls whatever the binder used; the degradation of R salivary binder was different in pancreatic insufficiency and in controls. Despite the in vitro abnormalities observed in pancreatic insufficiency, these did not correlate with the in vivo absorption of cobalamin which was often normal in our patients.