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We evaluated the incidence of GVHD, risk factors and the impact of graft composition on acute GVHD (aGVHD) in 92 children who underwent BMT for thalassemia following busulfan/cyclophosphamide (BUCY)-based conditioning regimens and GVHD prophylaxis with CSA/short-MTX and methylprednisolone. The incidence of grade 2-4 and 3-4 aGVHD was 35% (95% confidence interval (CI) 25-44) and 9% (95% CI 4-16), respectively. We found that CD3+ and CD34+ cell doses above the median were associated with high incidence of grade 2-4 aGVHD (49 vs 20%, P=0.005 and 46 vs 23%, P=0.021, respectively). In multivariate analysis, high CD3+ (hazard ratio (HR) 4.6; 95% CI 1.4-14.7; P=0.010) and CD34+ (HR 4.3; 95% CI 1.4-12.7; P=0.011) cell doses were associated with grade 2-4 aGVHD. We further examined the effect of CD3+ and CD34+ cell doses on aGVHD using quartile cutoff points and found a minimum threshold for CD3+ (38 × 106/kg) and CD34+ (4 × 106/kg) cells above which the incidence of grade 2-4 aGVHD is significantly increased. This study shows for the first time a positive correlation between the number of CD3+ and CD34+ cells and aGVHD in children receiving sibling BMT, and indicates that using tailored and more intensive post transplant immunosuppression may permit to better control aGVHD. [ABSTRACT FROM AUTHOR]

To investigate an association between KI and WU polyomavirus (KIPyV and WUPyV) infections and CD4+ cell counts, we tested HIV-1-positive patients and blood donors. No association was found between cell counts and virus infections in HIV-1-positive patients. Frequency of KIPyV infection was similar for both groups. WUPyV was more frequent in HIV-1-positive patients. [ABSTRACT FROM AUTHOR]

Three different methods for determination of CD34+ cells in G-CSF-mobilized peripheral blood were compared. The methods were: the Milan/Mulhouse protocol, the ISHAGE guidelines for CD34+ cells enumeration and our own protocol. The procedure we have adopted is essentially a Milan/Mulhouse protocol-derived methodology combined with a multiparametric approach using the PAINT-A-GATE software analysis program. The samples were collected from 70 patients affected by acute leukemia, non-Hodgkin’s lymphoma, Hodgkin’s lymphoma, myeloma and breast cancer who were scheduled to receive autologous PBSC transplantation. PBSC collection was performed following mobilization with subcutaneous G-CSF at 5–10 μg/kg/day. A minimum target of 2 × 106/kg CD34+ cells was considered an acceptable harvest to ensure a safe transplant. On average, three aphereses per patient were performed and a total of 204 apheresis samples were analyzed. Regression analysis of the percentage and absolute number of CD34+ cells, as calculated with each method, achieved an excellent correlation in spite of methodological differences. In fact, both CD34+dim and CD34+CD45- events were included in our gating strategy. In the setting of a triple staining associating CD34, CD38 and CD45, we identified a variable fraction of CD34+CD38+CD45- cells which would be otherwise undetected due to its CD45 negativity. To this end, we used a new technology referred to as laser-scanning cytometry (LSC) which allowed the isolation and morphological identification of CD34+CD45- cells. By comparing CD34+CD45+ and CD34+CD45- cells, we found that they share a common morphology, thus confirming the hypothesis that the latter are to be considered for CD34+ cell calculation. The median number of... [ABSTRACT FROM AUTHOR]

BACKGROUND PBPC transplantation has become a widely accepted therapeutic option for patients with chemotherapy-sensitive malignancies. PBPCs facilitate even the transplantation of mismatched allogeneic cells, because of their better engraftment. PBPCs are harvested by leukapheresis after mobilization with G-CSF or chemotherapy and G-CSF. To improve the purity and yield of PBPC grafts, to ensure reproducibility of the procedure and to reduce platelet loss in the patient/donor, different fully automated PBPC collection systems were developed. We report here our experience with the new Amicus blood cell separator. METHODS From July 2000 to March 2001, 46 procedures were performed. Six donors underwent leukaphereses after G-CSF administration (10-12 microgr/Kg/day) beginning on day 4; 14 patients were harvested after chemotherapy and G-CSF or GM-CSF mobilization, when the peripheral CD34+ cell count was >20 cells/micrL. Peripheral venous access was preferred whenever possible, otherwise femoral or subclavian catheters were used. Complete cell counts and CD34+ cell evaluations were done both in patients and donors, before and after each procedure and in all the products of the apheresis. RESULTS A median of 8.959 L of blood (range 3.585-17.021 ) was processed with a duration of 315 minutes (range 215-400) at a blood flow rate of 40 ml/min (range 25-70). ACD was used at a ratio of 1:14. The products of apheresis had a median volume of 143 ml (range 70-306) and a Hct of 12.9% (range 1.6-21). Platelet contamination was low (722 × 10[sup 9]/L, range 55-1,620), according to a low collection efficiency (12%, range 2-34) and a low decrease of platelet level both in donors and patients (21 × 10[sup 9]/L, range 3-83); in contrast, CD34 + cell collection efficiency was high (59.5%, range 15-97). No adverse affects were observed. CONCLUSIONS Amicus blood cell separator has a high collection efficiency for PBPC collections and improves donor safety by reducing platelet loss. [ABSTRACT FROM AUTHOR]

Thalassemic diseases are characterized by a reduced (β + ) or absent (β 0 ) synthesis of the globin chains of hemoglobin (Hb) due to genetic mutations. β-thalassemia was more frequent in the Mediterranean area, but now it is diffused worldwide. Three possible genetic forms can be distinguished: β 0 /β 0 , the most severe (Cooley's disease); β 0 /β + of intermediate severity; β + /β + associated with β-thalassemia intermedia or minor. Recently, a clinical non-genetic classification has been proposed: transfusion-dependent thalassemia (TDT), requiring regular lifetime blood transfusions, and non-transfusion-dependent thalassemia (NTDT), requiring occasional transfusions to manage acute cases. In this report, we studied a patient whose blood count indicated a severe anemia but also showed thrombocytosis, leukocytosis, and an elevated number of nucleated red blood cells (NRBC). These altered blood parameters suggested initially a possible diagnosis of hemoglobinopathy or myeloproliferative syndrome. The molecular and genetic analyses demonstrated the presence of HbF (5.3%) and HbA2 (7.7%) and the presence of the homozygote mutation (IVS1.6T>C) in the β-globin gene. According to these data, a diagnosis of β-thalassemia intermedia form has been proposed. Nevertheless, the clinical condition, the presence of thrombocytosis, leukocytosis, an elevated number of NRBC, and the frequent blood transfusions lead to reclassification of the patient as TDT subject. Consequently, this result suggests that a unique genotype-phenotype correlation is not possible in the presence of β + mutations since other concomitant pathologies can exacerbate the disease., Competing Interests: The authors declare that they have no conflict of interest., (Copyright 2024, Castelgrande et al.)