This report presents a case of an adult Polish women of Caucasian origin who was heterozygous for the nondeletional mutation: Hb Handsworth (HBA2 or HBA1: c.55G > C, p.Gly19Arg) and deletional (-α3.7) α-thalassemia mutation.
The HbA2 and HbF levels were measured by microcolumn chromatography and alkaline denaturation procedure, respectively, while electrophoresis was used to detect pathological hemoglobin fraction. The β- and α-globin genotypes were determined by DNA sequencing, gap-polymerase chain reaction, α gene triplication and MLPA.
The HbA2 and HbF levels were normal, but hemoglobin electrophoresis on agarose gel alkaline pH showed a strong band migration in a position of hemoglobin S and faint bands in the neighborhood of band A on acid electrophoresis. Molecular analysis of the alpha globin cluster detected a point mutation at codon 19 in HBA2 (c.55G > C, p.Gl- y19Arg) and deletion -α3.7.
Our compound heterozygosity does not produce severe clinical or hematological symptoms but it is important to say that in our part of Europe such cases do appear. Molecular analysis of the alpha globin cluster is required for correct diagnosis in patients with normal HbA2 levels. Compound heterozygosity was unmasked by molecular diagnosis only.
Autologous hematopoietic stem cell transplantation (autoHSCT) requires collection of sufficient number of hematopoietic stem cells. The goal of this study was to evaluate efficacy of plerixafor used in patients with lymphoid malignancies failing conventional stem cell mobilization.
This was a prospective, non-interventional study. All consecutive patients (n = 109) treated with plerixafor in 11 centers were reported. The drug was used either in case of previous mobilization failure (n = 67) or interventionally, in case of insufficient CD34+ cell output during current mobilization (n = 42). Successful mobilization was defined as resulting in collection of ≥ 2 × 106 CD34+ cells/kg for single autoHSCT or ≥ 4 × 106 CD34+ cells/kg for double procedure.
The overall rate of successful mobilization was 55% (55% for single and 56% for double autoHSCT). The median total number of collected CD34+ cells/kg was 2.4 (range, 0-11.5) for patients intended for a single transplantation while 4.0 (0.6-16.9) for double procedure. The number of circulating CD34+ cells increased after the use of plerixafor regardless of baseline values. The median fold increase was 3.3 (0.3-155). Data from this observational study confirm high efficacy of plerixafor used in routine clinical practice as salvage for patients with lymphoid malignancies failing conventional stem cell mobilization.