Catherine Curtillet

Health status and quality of life in long-term survivors of childhood leukaemia: the impact of haematopoietic stem cell transplantation.

We compared late side effects and quality of life (QoL) in 430 survivors of childhood acute leukaemia based on whether they had undergone haematopoietic cell transplantation (n=142) or not (n=288). Mean age was 18.2 years and mean follow-up duration was 11.9 years. Multivariate logistic regression analyses were performed to compare the risk of each type of late effect in the two groups. Based on age, VSP-A or SF36 questionnaires were used to assess QoL. For each QoL dimension, multiple linear regression was done to construct models of association with the treatment group. Transplanted patients experienced more side effects, including height growth failure, gonadal dysfunction, hypothyroidism and cataract. Children and adolescents in the two treatment groups reported similar QoL levels for almost all dimensions except a better perception of school work by young transplanted children and more difficulties in relating to the medical staff for transplanted adolescents. In adults, two differences in physical domain of QoL were detected but the calculated effect sizes were less than 0.2 in each case, suggesting an uncertain clinical significance. In spite of a higher risk of physical adverse events in the transplanted group, very few clinically significant differences in QoL are detectable.

CD34 + progenitors are reproducibly recovered in thawed umbilical grafts, and positively influence haematopoietic reconstitution after transplantation

Cord blood (CB) units are increasingly used for allogeneic transplantation. Cell dose, a major factor for CB selection, is evaluated before freezing by each CB bank, using various techniques. This may introduce variability and affect the prediction of cell recovery after thawing, or haematopoietic reconstitution. Forty-two children were transplanted at the same institution with unrelated CB units. All units were thawed and evaluated at the same cell therapy facility, using standard procedures. We investigated: (i) factors that affect cell loss after thawing, and (ii) the importance of CD34+ cell doses. Prefreeze and post-thaw CD34+ cell doses were statistically correlated, thus suggesting that variability in numeration techniques used by different CB banks does not compromise the biological and clinical value of these figures. CD34+ cell recovery appeared to be correlated with the absolute number of CD34+ cells per frozen bag. Infused CD34+ is the cell dose that better correlates with platelet reconstitution delay; in addition, when using a quartile comparison, haematopoietic recovery appeared to be related with prefreeze and post-thaw CD34+ cell doses. We conclude that enumeration of CD34+ cells in CB units is of biological significance, and may help select CB units and identify patients at risk of delayed recovery.

Peripheral blood cells chimerism after unrelated cord blood transplantation in children: kinetics, predictive factors and impact on post‐transplant outcome

This study aimed to describe kinetics of complete donor chimerism occurrence (cDC, >99·9% donor) after unrelated cord blood transplantation (UCBT), to identify its predictive factors and its impact on post‐transplant outcome. Ninety‐four children who received single UCBT after a myeloablative conditioning regimen had blood chimerism evaluation at predefined post‐transplant dates, using a real‐time polymerase chain reaction method with 0·1% sensitivity. Cumulative incidence of cDC at 1 year post‐transplantation was 61·8%. Three predictive factors were identified in multivariate analysis: history of malignant disease (P = 0·03), older age (above 2·16 years, the first quartile of age, P = 0·0055) and higher level of cord/recipient human leucocyte antigen mismatch (4/6 vs. 5‐6/6, P < 0·001) increased the probability of post‐transplant cDC. Although graft cell dose had a strong impact on haematological recovery, it did not apparently influence cDC occurrence. Early cDC (i.e. more than 99·9% donor chimerism on days 15–30 post‐transplant) appeared useful to predict engraftment (P = 0·003) as well as acute and chronic graft‐versus‐host disease (GvHD). Severe acute or chronic GvHD never occurred in patients with DC ≤99·9%, suggesting than even minimal residual host haematopoiesis is associated with a very low risk of GvHD after UCBT.

Molecular and fluorescence in situ hybridization analysis of a 10;11 rearrangement in a case of infant acute monocytic leukemia

Fluorescence in situ hybridization (FISH) analysis in a case of infant acute monocytic leukemia M5 revealed a complex rearrangement between chromosomes 10 and 11, leading to the disruption of the MLL gene. Using two painting probes for chromosomes 10 and 11 and a specific probe for the MLL gene localized on 11q23, we observed a paracentric inversion of the 11q13-q23 fragment translocated to 10p12. Molecular analysis showed that AF10 localized on 10p12 was the fusion partner gene of MLL in this rearrangement (10;11). This report underlined the usefulness of FISH and molecular techniques in identifying complex rearrangements.

A new case of t(8;14)(q11;q32) in an acute lymphoblastic leukemia

Case report of a translocation : A new case of t(8;14)(q11;q32) in an acute lymphoblastic leukemia.

Translocation t(2;19)(p11;p12-p13) in childhood with acute myeloid leukemia

Case report of a translocation : Translocation t(2;19)(p11;p12-p13) in childhood with acute myeloid leukemia.