Suppression of Hb Bart's to improve tissue oxygenation and fetal development in homozygous alpha-thalassemia

Intra-uterine reduction of Hb Bart's only reached with exchange transfusions.

A neonate with spontaneous arterial limb ischemia and an aneurysm of the oval foramen: a case report

Background

In this case report, we describe a very rare case of severe limb ischemia due to an arterial embolus caused by an aneurysm of the oval foramen in a term-born infant that occurred in the first few hours after birth.

Case presentation

A newborn male Caucasian patient presented on the maternity ward with ischemia of the right foot. Ischemia was treated with nitroglycerin spray and low-molecular-weight heparin in therapeutic dosage. An aneurysm of the oval foramen was found during postnatal echocardiography screening. This was thought to be the source of an embolus causing limb ischemia. At birth and upon follow-up, no clotting disorders were found. A large part of the right forefoot was ischemic, leading to loss of digits 1, 2, and 3. No significant loss of function was found in the first year of life.

Conclusion

Severe limb ischemia can be caused by an embolus arising from an aneurysm of the oval foramen and can be treated with heparin.

Impact of von Willebrand disease on health-related quality of life in a pediatric population

BACKGROUND

Von Willebrand disease (VWD) is the most frequent inherited bleeding disorder. Whether VWD is associated with health-related quality of life (HR-QoL) in children is unknown.

OBJECTIVES

This nationwide cross-sectional study measured HR-QoL in children with moderate or severe VWD. Our primary aim was to compare HR-QoL of VWD patients with that of reference populations. Additionally, we studied the impact of bleeding phenotype and VWD type on HR-QoL.

METHODS

HR-QoL was assessed with the Infant/Toddler QoL Questionnaire (0-5 years) and Child Health Questionnaire (6-15 years), and compared with reference population scores. Multivariate analysis was used to evaluate the influence of type of VWD and bleeding phenotype on HR-QoL scores.

RESULTS

Preschool children (0-5 years, n = 46) with VWD had lower HR-QoL scores for general health perceptions and parental time than reference populations. School children (6-15 years, n = 87) with VWD had lower scores for physical functioning, role functioning - emotional/behavioral, general health perceptions, and physical summary. Type of VWD was associated with HR-QoL in school children for bodily pain, general health perceptions, parental emotion, family activities, and physical summary. Scores of children with type 3 VWD were, on average, 15 points lower than those of the reference population on the above-mentioned scales. A more severe bleeding phenotype was associated with a lower score on 11/15 physical, emotional and social scales.

CONCLUSION

HR-QoL is lower in VWD children than in reference populations, in particular in school children. The negative impact of VWD is sensitive to type of VWD and bleeding phenotype; as well as physical scales, emotional and social scales are affected.

Paediatric allogeneic bone marrow transplantation for homozygous beta-thalassaemia, the Dutch experience

We reviewed the results of the Dutch paediatric bone marrow transplant (BMT) program for children receiving HLA-identical BMT for beta-thalassaemia major over an 18-year period. In all, 19 patients underwent a total of 21 transplants in our treatment centre between July 1984 and February 2002. Eight females (age 0.3-12 years; median 5 years) and 11 males (age 0.8-18 years; median 6 years) were included. Information, prospectively collected, included molecular defects, donor genotype, beta/alpha-globin expression rates, serum ferritin levels, hepato-splenomegaly, chelation history, virology screening, liver pathology together with post-transplant outcome inclusive of leucocyte chimerism. In total, 11 patients received standard busulphan/cyclophosphamide (Bu/Cy) conditioning, with or without ATG. Stable engraftment was seen in 5/11 with late rejection occurring in six patients. Of these, two children underwent a second successful SCT. For this group, overall event-free survival (EFS) and disease-free survival (DFS) were 90 (10/11) and 64% (7/11), respectively. The probability of rejection was 55%. Subsequent addition of melphalan to the conditioning regimen resulted in long-term stable engraftment in all patients with an EFS/DFS for this group of 90% (9/10). Treatment-related mortality, irrespective of conditioning, was low at 5% (1/19 patients). Veno-occlusive disease (VOD) occurred in 19% (4/21 transplants) and acute GvHD in 19% (4/21 transplants). Post-BMT beta/alpha synthetic ratio measurement monitored donor erythroid engraftment and predicted rejection with a return to transfusion dependency. Maintained full donor chimerism is indicative of stable engraftment both for leucocyte and erythroid lineages, whereas mixed donor chimerism is not. Our results emphasise the importance of the conditioning regimen and post-transplant chimerism surveillance predictive of rejection or long-term stable engraftment.

CD20 and CD40 mediated mitogenic responses in B-lineage acute lymphoblastic leukaemia

Activation of CD20, a cross-membrane ion channel, induces cell cycle progression from G0 to G1 in B lymphocytes. Subsequent activation of CD40, a membrane receptor of the nerve growth factor receptor superfamily, transits the B cells to the S phase. CD40 may also act synergistically in combination with IL-4 (B lymphocytes) or IL-3/IL-7 (B-cell precursors). We investigated the proliferative responses of B-lineage acute lymphoblastic leukaemia (ALL) cells to CD20/CD40 activation. In 18/56 ALL cases, CD20 activation resulted in significant increases in DNA synthesis. Similar, although more moderate, effects were seen of activation of CD40 in 10/44 cases. Responses to CD20 or CD40 activation were independent of co-stimulation with IL-3, IL-4 or IL-7, and various cocktails of the different growth stimuli did not act synergistically.

Heterogeneity of proliferative responses of human B cell precursor acute lymphoblastic leukemia (BCP-ALL) cells to interleukin 7 (IL-7): no correlation with immunoglobulin gene status and expression of IL-7 receptor or IL-2/IL-4/IL-7 receptor common gamma chain genes

Interleukin 7 (IL-7) stimulates proliferation of normal human and murine B cell precursor (BCP) cells in a distinct fashion, depending on the stage of maturation of the cells. For instance, the productive rearrangement of the immunoglobulin heavy chain gene has been demonstrated to be essential for the response of BCP cells to IL-7 as the single proliferation stimulus. IL-7 activates a receptor that consists of the IL-7R protein and the common gamma chain (gamma c). BCP acute lymphoblastic leukemia (BCP-ALL) cells variably respond to IL-7. Among 72 cases of BCP-ALL IL-7 activated DNA synthesis in 34. In four cases inhibition of DNA synthesis was seen. In the remaining 38 cases IL-7 exerted no effects. We determined whether this heterogeneity in IL-7 response could be correlated with parameters that could influence the IL-7 response. Firstly we show that, in contrast to the murine BCP cells, the IL-7 response of human BCP-ALL cells did not correlate with the status of IgH chain gene rearrangement and expression, nor with the rearrangement of IgL chain genes. Subsequently, it is demonstrated that IL-7R protein and transcripts as well as gamma c transcripts are equally present in the IL-7 responsive and nonresponsive BCP-ALL samples, indicating that the defective expression of these chains could not be held responsible for IL-7 response failures. Finally, we observed that kit ligand (KL), known to synergize with IL-7 in the most primitive stages of normal B cell development, did not enhance the IL-7 responses of BCP-ALL cells.

Further characterization of the 5'-flanking region of the rat lactase-phlorizin hydrolase gene

The lactase-phlorizin hydrolase gene is widely used as a marker of intestinal differentiation. Recent evidence demonstrating that transcription plays a major role in the regulation of this gene suggests that study of the 5'-flanking region will allow an understanding of how the expression of this gene is controlled. However, sequence, restriction, and primer extension analysis of a rat genomic clone has revealed that previously published data are incomplete. In the present study, we used a directed sequencing strategy to carefully analyze this region. Our expanded analysis of the 5'-flanking region of the lactase-phlorizin hydrolase gene should facilitate future studies of its structure and function.