Nadira Azzi

Haematopoietic stem cell transplantation for severe sickle cell disease in childhood: a single centre experience of 50 patients

Despite improvements in medical management, sickle cell disease (SCD) remains associated with severe morbidity and decreased survival. Allogeneic haematopoietic stem cell transplantation (HSCT) remains the only curative approach. We report the outcome of 50 consecutive children with severe SCD that received HSCT in our unit between November 1988 and April 2013. The stem cell source was bone marrow (n = 39), cord blood (n = 3), bone marrow and cord blood (n = 7) and peripheral blood stem cells (n = 1). All patients had ≥1 severe manifestation: 37 presented with recurrent vaso‐occlusive crises/acute chest syndrome, 27 cerebral vasculopathy and 1 nephropathy. The conditioning regimen consisted of busulfan + cyclophosphamide (BuCy) before November 1991 and BuCy + rabbit antithymocyte globulin after that date. Since 1995, all patients have been treated with hydroxycarbamide (HC) prior to transplantation for a median duration of 2·7 years. Median age at transplantation and median follow‐up was 8·3 and 7·7 years, respectively. Acute graft‐versus‐host disease (GVHD) and chronic GVHD were observed in 11 and 10 patients, respectively. An excellent outcome was achieved, with 8‐year overall survival and event‐free survival (EFS) rates of 94·1% and 85·6%, respectively. Since HC introduction, no graft failure occurred and EFS reached 97·4%. Prior treatment with HC may have contributed to successful engraftment.

Reversible acute methotrexate leukoencephalopathy: atypical brain MR imaging features

Background: Unusual acute symptomatic and reversible early-delayed leukoencephalopathy has been reported to be induced by methotrexate (MTX). Objective: We aimed to identify the occurrence of such atypical MTX neurotoxicity in children and document its MR presentation. Materials and methods: We retrospectively reviewed the clinical findings and brain MRI obtained in 90 children treated with MTX for acute lymphoblastic leukaemia or non-B malignant non-Hodgkin lymphoma. All 90 patients had normal brain imaging before treatment. In these patients, brain imaging was performed after treatment completion and/or relapse and/or occurrence of neurological symptoms. Results: Of the 90 patients, 15 (16.7%) showed signs of MTX neurotoxicity on brain MRI, 9 (10%) were asymptomatic, and 6 (6.7%) showed signs of acute leukoencephalopathy. On the routine brain MRI performed at the end of treatment, all asymptomatic patients had classical MR findings of reversible MTX neurotoxicity, such as abnormal high-intensity areas localized in the deep periventricular white matter on T2-weighted images. In contrast, the six symptomatic patients had atypical brain MRI characterized by T2 high-intensity areas in the supratentorial cortex and subcortical white matter (n=6), cerebellar cortex and white matter (n=4), deep periventricular white matter (n=2) and thalamus (n=1). MR normalization occurred later than clinical recovery in these six patients. Conclusions: In addition to mostly asymptomatic classical MTX neurotoxicity, MTX may induce severe but reversible unusual leukoencephalopathy. It is important to recognize this clinicoradiological presentation in the differential diagnosis of acute neurological deterioration in children treated with MTX.

Children with sickle cell disease: growth and gonadal function after hematopoietic stem cell transplantation.

The aim of this study is to describe the growth, pubertal development, and gonadal function of a cohort of 30 sickle cell disease children who underwent bone marrow transplantation. They all received the standard pretransplant conditioning regimen of busulfan (14 or 16 mg/kg) and cyclophosphamide (200 mg/kg). Growth was normal both before and after transplant. Seven out of 10 girls had severe ovarian failure and requirement for estrogen replacement. Three out of 10 girls recovered some ovarian function posttransplant, with spontaneous pubertal development, menses, and 1 successful normal pregnancy. Follicle-stimulating hormone (FSH) serum levels were very high during spontaneous puberty and slowly normalized thereafter in these 3 patients. The 3 girls with ovarian function recovery differed from the 7 others by the lower busulphan dose of the conditioning regimen they received (14 rather than 16 mg/kg). All boys showed spontaneous pubertal development. However, most of them had small testis and elevated serum FSH levels, reflecting germinal epithelium damage. Testosterone level was low normal and luteinizing hormone elevated, reflecting Leydig cell insufficiency. In conclusion, 7/10 girls had complete gonadal failure and most of the boys had spontaneous puberty but germinal epithelial failure. Serum FSH levels showed important variations over time in the same patient.

Bone marrow transplantation for severe sickle cell anaemia

Summary. Five children with sickle cell anaemia underwent bone marrow tranplantation (BMT) for severe clinical disease. The conditioning regimen for BMT was in busulfan plus cyclophosphamide. The allograft contained more than 5.108 nucleated cells per kg recipient. Prophylaxis of GVHD consisted of methotrexate and cyclosporin A. Therapy was well tolerated. Duration of neutropenia (<0.5 × 109/1) was short (14–25 d). Platelet recovery (>50 × 109/1) occurred between day 12 and 45. The patients have been folowed up for 8–28 months. No major infections occurred and long‐term BMT‐related toxicity was limited to mild, chronic GVHD in one patient. Mean haemoglobin levels remained above 10 g/dl. Haemoglobin electrophoresis showed AS patterns in all grafted patients—all marrow donors having sickle cell trait. From our preliminary data, we conclude that BMT or sickle cell anaemia is curative, well tolerated and should be proposed for suitable patients.

Hydroxyurea treatment for sickle cell disease: impact on haematopoietic stem cell transplantation's outcome

Summary:Since 1988, 24 children have undergone haematopoietic stem cell transplantation (HSCT) for severe sickle cell disease (SCD) in our unit, 13 being grafted after having been exposed to hydroxyurea (HU) to control SCD-related complications. Different pre-transplant conditioning regimens were given over time: Bu14/Cy200 in six patients (group 1), Bu16/Cy200/antithymocyte globulin (ATG) in five (group 2) and Bu16/Cy200/ATG with HU prior to HSCT in 13 (group 3). The aim of this study is to compare the outcome after HSCT of these groups of patients, which differ according to pre-transplant drug exposure. Overall, 20 of the 24 transplanted children had stable engraftment and have remained free of SCD-related symptoms after HSCT; 19 of them are currently alive and cured of SCD. In group 1 (HU−, ATG−), we observed one unexplainable late death, one absent engraftment, one late rejection and one mixed stable chimerism. In group 2 (HU−, ATG+), we observed the absence of engraftment in two patients and one early rejection. In group 3 (HU+, ATG+), we observed no cases of either absent engraftment, mixed stable chimerism or late rejection. In our experience, pre-transplant treatment with HU seems to be associated with a lower incidence of rejection/absent engraftment in severe SCD patients. These results need to be confirmed with a larger number of patients.

Use of recombinant human granulocyte colony stimulating factor in reticular dysgenesis

was negative. Renal and hepatic function tests were within normal limits. No source of infection could be demonstrated on chest X-ray, and blood and urine cultures were negative. She was treated with transfusions of packed red cells and platelet concentrates, and broad-spectrum antibiotics. TWO days after admission, she had massive gastrointestinal haemorrhage as a result of which the haemoglobin decreased to 4 g/dl. Due to lack of availability of a histocompatible sibling for BMT, it was decided to try immunosuppression with total lymphoid irradiation (TLI) and intravenous methylprednisolone. The patient was given 800 cGy TLI in four fractions of 200 cGy each over 2 d followed by intravenous methylprednisolone at the following doses: 30 mg/kg/d x 3 d, 20 mg/kg/ d x 4 d, 10 mg/kg/d x 4 d, and 5 mg/kg/d x 4 d. On the fourth day of therapy the investigations showed: haemoglobin 7.3 g/dl. leucocytes 1.5 x 10y/l (50% granulocytes), platelets 90 x 10y/l, and reticulocytes 0.5%. At the end of 15 d of intravenous steroid administration the counts were: haemoglobin 8 g/dl. leucocytes 2 . 7 x 10y/l (granulocytes 70%), platelets 180 x 10y/l, and reticulocytes 1%. The patient received 4 weeks of oral prednisolone 1 mg/kg after cessation of the intravenous methylprednisolone. At the end of all therapy the counts were: haemoglobin 11.5 g/dl, leucocytes 4.5 x 10y/l (granulocytes 71%). platelets 2 3 0 x 109/1, and reticulocytes 1 * 5%. The patient is asymptomatic and haematologically normal 6 months after therapy. Long-term follow-up of patients of aplastic anaemia who achieved complete haematologic remission with immunosuppression has shown late development of myelodysplasia and acute myeloid leukaemia (De Planque et al. 1988). Because aplastic anaemia is a stem cell disorder, the basic anomaly can be rectified only with BMT. However, BMT is not a suitable option in a number of patients due to lack of availability of suitable donors. While the duration of the follow-up is still short, the preliminary result in this patient seems to be highly encouraging. We did not encounter any serious adverse reaction to the irradiation and the high-dose methylprednisolone. In our opinion, TLI and methylprednisolone should be considered a therapeutic option in patients with SAA who are not candidates for BMT or antithymocyte globulin, or those who have failed one course of therapy with antithymocyte globulin.

Detection of Herpesviridae in Whole Blood by Multiplex PCR DNA-Based Microarray Analysis after Hematopoietic Stem Cell Transplantation

ABSTRACT Viral infections are important causes of morbidity and mortality in patients after hematopoietic stem cell transplantation. The monitoring by PCR of Herpesviridae loads in blood samples has become a critical part of posttransplant follow-up, representing mounting costs for the laboratory. In this study, we assessed the clinical performance of the multiplex PCR DNA microarray Clart Entherpex kit for detection of cytomegalovirus (CMV), Epstein-Barr virus (EBV), and human herpesvirus 6 (HHV-6) as a screening test for virological follow-up. Two hundred fifty-five blood samples from 16 transplanted patients, prospectively tested by routine PCR assays, were analyzed by microarray. Routine PCR detected single or multiple viruses in 42% and 10% of the samples, respectively. Microarray detected single or multiple viruses in 34% and 18% of the samples, respectively. Microarray results correlated well with CMV and EBV detections by routine PCR (kappa tests = 0.79 and 0.78, respectively), whereas a weak correlation was observed with HHV-6 (0.43). HHV-7 was also detected in 48 samples by microarray. In conclusion, the microarray is a reliable screening assay for a posttransplant virological follow-up to detect CMV and EBV infections in blood. However, positive samples must be subsequently confirmed and viral loads must be quantified by PCR assays. Limitations were identified regarding HHV-6 detection. Although it is promising, is easy to use as a first-line test, and allows a reduction in the cost of analysis without undue delay in the reporting of the final quantitative result to the clinician, some characteristics of this microarray should be improved, particularly regarding quality control and the targeted virus panel, such that it could then be used as a routine test.

Complications of lumbar puncture in a child treated for leukaemia

Lumbar puncture may lead to neurological complications. These include intracranial hypotension, cervical epidural haematomas, and cranial and lumbar subdural haematomas. MRI is the modality of choice to diagnose these complications. This report documents MRI findings of such complications in a child treated for leukaemia.

A pilot study of manual chronic partial exchange transfusion in children with sickle disease

Abstract Objective Red cell exchange transfusion is frequently used in the management of patients with sickle cell disease (SCD) either electively or chronically to maintain hemoglobin S (HbS) <30%. The purpose of this retrospective study was to evaluate the results of manual chronic partial exchange transfusion (MCPET) on level of Hb and HbS, on iron load and on the need for chelation, on risk of immunization, monitoring transfusion-transmitted viral infection, and clinical outcome. Methods We reviewed the long-term effect of MCPET in 10 children (six men and four women) with SCD and evaluated the iron balance during a median follow-up of 20 months (range: 6–36) in which 248 exchanges were performed. Results The pre-exchange median Hb value was 9.5 g/dl (range: 7.7–10.9 g/dl) and the median post-exchange value was 9.4 g/dl (range: 8.4–11.1 g/dl).The majority of patients reached an HbS of <50% with a median HbS value of 40.04% (range: 30–54). At start of the MCPET program, the median ferritin was 439 ng/ml (range: 80–1704 ng/ml). In the final evaluation, the median value of ferritin was 531 ng/ml (range: 84–3840 ng/ml). The annual calculated iron balance was 0. 28 ± 0.08 mg/kg/day. MCPET was well tolerated, and adverse effects were limited. Discussion MCPET in children with SCD is safe to prevent iron overload, and is effective and easy to use in our cohort. Conclusion Indication for chronic exchange blood transfusion is essential for patients with SCD with recurrent and frequent crises who do not respond to hydroxyurea. However, there is no consensual study for the period at which chronic transfusion can safely be stopped and further research in large population of patients with SCD will need to clarify this question.

Is Pica under-reported in children with sickle cell disease? A pilot study in a Belgian cohort

Abstract Background For centuries, writers have recorded their observations on pica. Nevertheless the association of pica with sickle cell disease (SCD) was poorly documented. Methods Cross-sectional evaluation performed on SCD children and caregivers attending the outpatient clinic who were invited to complete questionnaires assessing behavior of pica. Results Out of 55 sickle cell children, 31(56.4%) reported practicing pica regularly. Substances ingested by patients covered a broad spectrum. Compared with the non-pica group, subjects who reported pica were younger and had lower hemoglobin (8.3 g/dl (7.6–9.7) vs. 9.1 g/dl (7.9–10.5): P < 0.01). The level of ferritin, zinc, copper, and lead was similar between the pica and non-pica groups (P > 0.05). Discussion In this series, there are many substances consumed by SCD children and adolescents, and we did not find an occurrence of similar substances among this select group. Pica children were younger and more anemic than non-pica patients. Conclusion This study suggests that pica remains an unknown and under-reported clinical problem in children with SCD and seems to be related to the severity of anemia. The next step of this project aims to clarify causal mechanisms for pica and its association with SCD in a larger population.