Cord blood transplantations in Polish pediatric centers: report of the Polish Pediatric Group for Hematopoietic Stem Cell Transplantation

WstępPrzeszczepianie komórek krwiotwórczych krwi pępowinowej (CBT) jest uznaną metodą terapeutyczną, wykonywaną od roku 1988. Pierwsze przeszczepienie w Polsce wyłącznie z krwi pępowinowej wykonano 12 października 2000 r. w Poznaniu.Cel pracyAnaliza wyników przeszczepiania komórek krwiotwórczych w polskich ośrodkach pediatrycznych.Pacjenci i metodykaDo badań włączono 19 pacjentów (5 dziewcząt, 14 chłopców), w wieku 0,1–10 lat (mediana 4,3 roku), u których w latach 2000–2011 w polskich ośrodkach pediatrycznych wykonano przeszczepienie krwi pępowinowej. Pacjentów kierowano do CBT z powodu następujących rozpoznań: ostra białaczka limfoblastyczna (n=6), ostra białaczka mieloblastyczna (n=1), zespół mielodysplastyczny (n=2), zespół Wiskotta i Aldricha (n=3), niedokrwistość Fanconiego (n=2), adrenoleukodystrofia (n=1), histiocytoza Langerhansa (n=1), przewlekła choroba ziarniniakowa (n=1), zespół Kostmanna (n=1), zespół Sandhoffa (n=1). Zastosowano kondycjonowanie mieloablacyjne u 9 pacjentów oraz o zredukowanej toksyczności u 10 pacjentów. Krew pępowinowa pochodziła od dawcy rodzinnego w 8 przypadkach lub od dawcy niespokrewnionego w 11 przypadkach. Zgodność 6/6 HLA wystąpiła w 10 przypadkach.Wyniki10/19 (52,6%) dzieci żyje, mediana przeżycia 3,1 roku (95%CI=1,4–4,7), prawdopodobieństwo przeżycia 2-letniego wynosi 0,409±0,133. Przyczyny zgonów obejmowały brak przyjęcia przeszczepu (n=2), powikłania infekcyjne (n=3) lub wznowę (n=4). Dwoje dzieci z powodu nieprzyjęcia przeszczepu miało wykonane przeszczepienie haploidentyczne. W analizie wielowariantowej, jedynym czynnikiem prognostycznym mającym wpływ na całkowite przeżycie było wystąpienie udokumentowanego uogólnionego zakażenia do dnia +180.WnioskiU pacjentów niemających zgodnego dawcy CBT jest ważną opcją terapeutyczną, dającą szanse wyleczenia dla około połowy pacjentów.BackgroundCord blood transplantation (CBT) is accepted therapeutic method in transplantology since 1988. The first isolated CBT was performed on 12 October 2000 in Poznań.ObjectiveAnalysis of results of CBT in Polish pediatric centers.Patients and methodsA total numer of 19 patients (5 female, 14 male), aged 0.1–10 years (median 4.3yrs) transplanted with cord blood between 2000–2011 in Polish pediatric centers. The initial diagnosis was: acute lymphoblastic leukemia (n=6), acute myeloid leukemia (n=1), myelodysplstic syndrome (n=2), Wiskott-Aldrich syndrome (n=3), Fanconi anemia (n=2), adrenoleukodystrophy (n=1), Langerhans cell histiocytosis (n=1), chronic granulomatous disease (n=1), Kostmann syndrome (n=1), Sandhoff syndrome (n=1). Pre-transplant conditioning was myeloablative in 9 patients and reduced-intensity in 10 patients. The source of cord blood was family donor in 8 cases or unrelated donor in 11 cases. Histocompatibility 6/6 HLA between donor-recipient was present in 10 cases.Results10/19 (52.6%) children stay alive, median survival 3.1 years (95%CI=1.4–4.7), probability of 2-year survival was 0.409±0.133. The cause of death was primary graft failure (n=2), infectious complications (n=3) or relapse (n=4). Two children with primary graft failure had subsequent haploidentical transplantation. In multivariate analysis, generalized documented infection was the only predictive adverse factor of overall survival.ConclusionCBT is an important therapeutic option for patients lacking matched donor, offering positive outcome for a half of patients

Cidofovir for BK Virus-Associated Hemorrhagic Cystitis: A Retrospective Study

Background.BK virus-associated hemorrhagic cystitis (BKV-HC) is a severe complication after allogeneic hematopoietic stem cell transplantation (HSCT), but antiviral treatment for this condition has not been evaluated. Methods.We conducted a retrospective survey on the safety and outcome of cidofovir treatment for patients with BKV-HC in centers affiliated with the European Group for Blood and Marrow Transplantation. Results.From 1 April 2004 to 31 December 2007, 62 patients received a diagnosis of BKV-HC after a median interval of 35 days after HSCT (range, 3-577 days). Fifty-seven patients (92%) received intravenous cidofovir, whereas 5 patients received cidofovir intravesically. Complete response (CR) was recorded in 38 (67%) of 57 patients with HC treated with intravenous cidofovir, whereas partial response (PR) was documented in 7 patients (12%). CR was documented in 3 patients and PR in 1 patient with HC treated with intravesical cidofovir. A reduction of 1-3 logs in BKV load was documented in 8 of the 10 patients achieving CR. Mild-to-moderate toxic effects were recorded in 18 of 57 patients who received intravenous cidofovir administration. In a multivariate analysis, the factors significantly associated with response to cidofovir were the stem cell source (P=.01) and the use of total body irradiation (P=.03). After a median follow-up of 287 days, overall survival and total treatment-related mortality rates were 63% and 40% for patients achieving CR, compared with 14% and 72% for patients with PR or no response to cidofovir, respectively (P<.001 and P=.001, respectively). Conclusions.Cidofovir may be a potentially effective therapy for BKV-HC, but evidence supporting its use requires randomized controlled trial

The role of MR imaging in the assessment of clinical outcomes in children with X-linked adrenoleukodystrophy after allogeneic haematopoietic stem cell transplantation

Background: The aim of the study was to analyse MR images of the brain, including advanced MR techniques, such as single voxel spectroscopy (MRS) and diffusion tensor imaging (DTI), in children with X-linked adrenoleukodystrophy (X-ALD) before and after haematopoietic stem cell transplantation (HSCT) and to establish the imaging criteria which may be helpful in the assessment of disease staging, qualification to HSCT and follow-up. Material and Methods: Seven boys, aged 5-10 years, (mean 8.14 years) with biochemically proved X-ALD, underwent plain MR imaging with a 1.5 T unit before and after HSCT. Structural images were analyzed using an MRI severity scale (Loes scale). In one patient the follow-up examinations included MRS with the assessment of metabolite ratios (NAA/Cr, Cho/Cr, mI/Cr), as well as DTI with evaluation of fractional anisotropy (FA) and apparent diffusion coefficient (ADC) in several white matter tracts. Results: Two boys had an MRI severity score before HSCT equal to <8 points, and after HSCT they showed no clinical or radiological progression. In 5 patients with a higher severity score (from 8 to 16 points, mean 10.9) before HSCT, clinical and radiological progression was observed (MRI severity score from 17 to 25 points, mean 20.9). Follow-up advanced MRI techniques in one boy showed metabolic alterations, as well as decreased FA and ADC values in all evaluated areas. Conclusions: Children at an early stage of X-ALD (below 8 points in MRI severity scale) are more likely to benefit from HSCT. DTI and MRS seem to be more useful imaging methods to assess the progression of X-ALD

COVID-19 mRNA Vaccine Tolerance and Immunogenicity in Hematopoietic Stem Cell Transplantation Recipients Aged 5–11 Years Old–Non-Randomized Clinical Trial

The SARS-CoV-2 pandemic had a devastating impact on the world’s population in the years 2020–2022. The rapid development of vaccines enabled a reduction in the mortality and morbidity of COVID-19, but there are limited data about their effects on immunocompromised children. The aim of this prospective study was to evaluate the safety and efficacy of the mRNA BNT162b2 (Pfizer/Biontech) vaccine in allogeneic hematopoietic stem cell transplantation (allo-HSCT) recipients. Material and methods: Two cohorts of 34 children after allo-HSCT and 35 healthy children aged 5–11 years were vaccinated with two doses of the mRNA BNT162b2 (10 µg) vaccine. All children were evaluated for adverse effects with electronic surveys and the immunogenicity of the vaccine was assessed with anti-SARS-CoV-2 IgG titer measurements. Results: All reported adverse events (AEs) were classified as mild. The most common AE was pain at the injection site. All the other AEs (both local and systemic) were rarely reported (2 years of age after HSCT who did not receive immunosuppressive treatment presented excellent antibody production after two doses of the vaccine, but children on immunosuppression may require a more intense vaccination schedule