Graft-versus-host Disease In Pediatric Patients Research Articles

Addition of ruxolitinib in Graft-versus-Host disease prophylaxis for pediatric β-Thalassemia major patients after allogeneic stem cell transplantation: A retrospective cohort study.

To evaluate the effect of addition of ruxolitinib in Graft-versus-Host Disease (GVHD) prophylaxis on pediatric patients with β-thalassemia major after allogeneic hematopoietic stem cell transplantation(HSCT). This retrospective study reviewed 49 consecutive β-thalassemia major pediatric patients who underwent HSCT from unrelated or haploidentical donors from February 2018 to October 2022. All transplantation recipients received cyclosporine A (CsA), mycophenolate mofetil (MMF), and short-term methotrexate (MTX) as GVHD prophylaxis; while 27 of them in the ruxolitinib group had added ruxolitinib oral to GVHD prophylaxis regimen at 2.5mg twice daily once successful engraftment after January 2020. The outcome showed that the ruxolitinib group had a lower cumulative incidence than the control group regardless of acute GVHD (22.2% vs.40.9%; p=.153) or chronic GVHD (18.5% vs.40.9%; p=.072); especially, the incidence of grade III-IV acute GVHD was reported significantly less frequently in ruxolitinib group than that of the control group (0 vs. 27.3%, p=.005). No significant difference was detected between the two groups in EBV (Epstein-Barr virus)/CMV (cytomegalovirus) reactivation and BKV (BK virus) infection (p=.703, 1.000, and .436, respectively). Twenty-six patients (96.3%) in the ruxolitinib group were alive, while two patients (9.1%) in the control group died of intestinal acute GVHD. The 2-year overall survival (OS) and thalassemia-free survival (TFS) were both 96.296% in the ruxolitinib group, while both 90.909% in the control group. This study reveals that ruxolitinib prophylaxis is a promising option to decrease the incidence of grade III-IV acute GVHD in pediatric patients with β-thalassemia major.

Association between Haploidentical Hematopoietic Stem Cell Transplantation Combined with an Umbilical Cord Blood Unit and Graft-Versus-Host Disease in Pediatric Patients with Acquired Severe Aplastic Anemia

Introduction: Haploidentical hematopoietic stem cell transplantation (haplo HSCT) based on granulocyte colony-stimulating factor plus anti-thymocyte regimens ("Beijing Protocol") provides a salvage treatment for patients of acquired severe aplastic anemia (SAA) in China. However, graft-versus-host disease (GVHD) is a major impediment of haplo HSCT due to HLA disparity. Human umbilical cord blood (UCB) is characterized by lower numbers of mature or primed T-cells. Additionally, UCB has been reported to be a rich and rapidly accessible source of regulatory T cells (Tregs) and mesenchymal stromal cells (MSCs). These characteristics of UCB make it a potential prophylactic method for GVHD. Recently, haplo HSCT combined with umbilical cord blood (UCB) (haplo-cord HSCT) is performed in clinical trials to potentially reduce the risk of severe GVHD. Nevertheless, studies comparing GVHD in pediatric patients receiving haplo and haplo-cord HSCT for SAA are limited. Herein, we aim to investigate the impact of UCB co-infusion on GVHD in pediatric patients receiving haplo HSCT for SAA. Methods: Data from 91 consecutive children with SAA treated with "Beijing Protocol"-based haploidentical transplantation with or without co-infusion of UCB between April 2015 and July 2021 in the Children's Hospital of Soochow University were retrospectively analyzed. The cohort included 35 patients in the haplo group and 56 patients in the haplo-cord group. All patients received uniform non-myeloablative conditioning, GVHD prophylaxis. We compared baseline characteristics and transplant outcomes between the haplo and haplo-cord recipients. Log-rank test and Cox proportional regression model were used for univariate and multivariate analysis, respectively. A significance level of 0.05 was used for all analyses. Results: No significant differences in the baseline information were observed between haplo and haplo-cord groups. All 91 patients achieved hematopoietic recovery from haploidentical donors, with a higher 30-day cumulative incidence of platelet engraftment observed with haplo group as compared to haplo-cord group (98.2% versus 97.1%, p = 0.028). Cox regression analysis revealed that the haplo or haplo-cord transplant type was not associated with the time to platelet engraftment, while a low CD34+ cell dose in haploidentical grafts was correlated with delayed platelet recovery (hazard ratio (HR), 2.495; 95% confidence interval (CI), 1.570-3.964; p < 0.001). The haplo-cord group showed a higher incidence of peri-engraftment syndrome compared to the haplo group (75.0% versus 48.6%, p = 0.029), and Cox regression analysis identified haplo-cord HSCT as the only significant factor associated with a higher incidence of peri-ES (HR, 1.767; 95% CI, 1.002-3.115; p = 0.049). Of note, the haplo-cord group showed a lower incidence of II-IV acute GVHD (aGVHD) than the haplo group (16.1% versus 42.9%, p = 0.002). Observed incidences of chronic GVHD (cGVHD) and moderate to severe cGVHD in the haplo-cord group were also lower than that in the haplo group (25.6% versus 51.3%, p = 0.019; 16.2% versus 41.3%, p = 0.016, respectively). Haplo-cord HSCT was identified as the only factor associated with a lower incidence of II-IV aGVHD (HR, 0.335; 95% CI, 0.143-0.784; p = 0.012) and cGVHD (HR, 0.429; 95% CI, 0.203-0.907; p = 0.027) in Cox regression analysis. No differences were observed between the two groups in CMV, EBV infection, overall survival, failure-free survival and GVHD, failure-free survival. Conclusions: Our study provided compelling results of descriptive analysis suggesting that co-infusion of a third-party UCB unit with haplo HSCT might be associated with a lower risk of II-IV aGVHD and cGVHD. Although this co-infusion protocol may come with a higher risk of peri-ES, the survival outcomes may not be negatively affected. Despite the limited sample size, this study is the first real-world comparative study to investigate the impact of haplo-cord HSCT on GVHD in SAA children, which may stimulate further research of haplo-cord HSCT in pediatric patients with SAA and hematologic malignancies, as well as the potential association with GVHD. Figure 1View largeDownload PPTFigure 1View largeDownload PPT Close modal

Association between haploidentical hematopoietic stem cell transplantation combined with an umbilical cord blood unit and graft-versus-host disease in pediatric patients with acquired severe aplastic anemia.

Haploidentical hematopoietic stem cell transplantation (haplo-HSCT) based on granulocyte colony-stimulating factor plus anti-thymocyte regimens ('Beijing Protocol') provides a salvage treatment for patients of acquired severe aplastic anemia (SAA) in China. However, graft-versus-host disease (GVHD) is a major impediment of haplo-HSCT due to human leukocyte antigen disparity. Recently, haplo-HSCT combined with umbilical cord blood (UCB) (haplo-cord HSCT) is performed in clinical trials to potentially reduce the risk of severe GVHD. Nevertheless, studies comparing GVHD in pediatric patients receiving haplo and haplo-cord HSCT for SAA are limited. The objective of this study was to investigate the impact of UCB co-infusion on GVHD in pediatric patients receiving haplo-HSCT for SAA. We conducted a retrospective study of 91 consecutive SAA children undergoing haploidentical transplantation based on the 'Beijing Protocol' with or without co-infusion of UCB in our center. All patients received uniform non-myeloablative conditioning and GVHD prophylaxis. We compared baseline characteristics and transplant outcomes between the haplo (n = 35) and haplo-cord (n = 56) recipients. All 91 patients achieved hematopoietic recovery from haploidentical donors, with a higher incidence of peri-engraftment syndrome observed with the haplo-cord group as compared with the haplo group (75.0% versus 48.6%, p = 0.029). Notably, the haplo-cord group showed a lower incidence of II-IV acute GVHD (aGVHD) than the haplo group (16.1% versus 42.9%, p = 0.002). Observed incidences of chronic GVHD (cGVHD) and moderate to severe cGVHD in the haplo-cord group were also lower than that in the haplo group (25.6% versus 51.3%, p = 0.019; 16.2% versus 41.3%, p = 0.016, respectively). Haplo-cord HSCT was identified as the only factor associated with a lower incidence of II-IV aGVHD and cGVHD in multivariate analysis. However, no differences were observed between the two groups for infections and survival outcomes. Our data indicated that co-infusion of UCB in 'Beijing Protocol'-based haplo-HSCT may be effective for reducing the risk of severe GVHD in SAA children.

Mesenchymal Stromal Cells in Pediatric Hematopoietic Cell Transplantation a Review and a Pilot Study in Children Treated With Decidua Stromal Cells for Acute Graft-versus-Host Disease.

Mesenchymal stromal cells (MSCs) are rare precursors in all organs of the body. MSCs have profound anti-inflammatory effects and reduce alloreactivity in vitro and in vivo. In pediatric allogeneic hematopoietic cell transplantation (HCT), MSCs have mainly been used to treat acute graft-versus-host disease (GVHD). MSCs are commercially available for this indication in Canada, Japan, and New Zeeland. More rare indications for MSCs in pediatric patients include graft failure and chronic GVHD. MSCs from bone marrow, adipose tissue, umbilical cord, Wharton's jelly, placenta tissue, and decidua have been used, but the optimal clinical stromal cell source has not been compared in clinical trials. More experimental clinical indications using MSCs, such as sepsis, acute respiratory distress syndrome, hemorrhages, pneumo-mediastinum, and neuroinflammation have primarily been explored in animal models or adult HCT patients. MSCs have almost no if any side-effects. In this pilot study we report the outcome of six children treated with decidua stromal cells (DSCs) for steroid refractory acute GVHD. At 6 months, complete response was seen in four patients and partial response in two patients. One child with high-risk ALL died from relapse and a boy with sickle cell disease died from a cerebral hemorrhage. Five-year survival was 67% and all survivors showed a Lansky score of 100%. To conclude, MSCs from various organs are well-tolerated and have shown an encouraging outcome for acute GVHD in pediatric patients.

Influence of anti-thymocyte globulin plasma levels on outcome parameters in stem cell transplanted children

IntroductionAllogenic hematopoietic stem cell transplantation is a curative option for malignant and non-malignant pediatric diseases. Serotherapy is often employed to avoid graft-versus-host disease (GvHD) on one hand and graft rejection on the other hand. Therapeutic drug monitoring is increasingly used to allow for more precise dosing especially in pediatric patients due to their specific pharmacological characteristics. Application of T-cell directed antibodies is not routinely monitored, but may benefit from more precise dosing regimens. MethodsTwo different preparations of rabbit anti-thymocyte globulin (rATG), Thymoglobuline® and ATG-F (Grafalon®), are frequently used to prevent GvHD in pediatric patients by in vivo T-cell depletion. Total rATG levels and active rATG levels were analyzed prospectively in pediatric patients undergoing HSCT. Clinical and laboratory outcome parameters were recorded. ResultsrATG levels were measured in 32 patients, 22 received thymoglobuline and 10 received ATG-F. The median total peak plasma level was 419.0 µg/ml for ATG-F and 60.4 µg/ml for thymoglobuline. For ATG-F, exposure could be predicted from the calculated dose more precisely than for thymoglobuline. Active peak plasma levels neither of ATG-F, nor of thymoglobuline correlated significantly with the number of lymphocytes prior to serotherapy. There was no significant difference in incidence of aGvHD, cGvHD, rejection, mixed chimerism or viral infections in the two cohorts. However, in our cohort, patients with high thymoglobuline exposure showed a compromised reconstitution of T cells. ConclusionsATG-F and thymoglobuline show different pharmacological and immunological impact in children, whose clinical significance needs to be investigated in larger cohorts.

Acute Graft Versus Host Disease (GVHD) Is Increased in Patients Receiving Cyclosporine/Cellcept as Frontline Prophylaxis Against GVHD in Pediatric Patients Undergoing Allogeneic Stem Cell Transplantation.

Traditionally, pediatric patients are prophylaxed against GvHD with cyclosporine (CSA) plus either methotrexate (Mtx) or methylprednisolone (Pred). Mtx worsens the severity of mucositis and renal insufficiency while pred causes muscle wasting, hypertension, hyperglycemia and increased infections. Cellcept (myophenolic acid) is a better tolerated, less toxic agent with synergistic immunosuppressive effects when combined with cyclosporine or tacrolimus. We explored its use in combination with cyclosporine in 63 pediatric patients (49% male, 74% Caucasian, 36% CMV+) undergoing allogeneic transplantation. Patients with both malignant (n=24) and non-malignant (n=39) conditions ranging in age from 2 weeks to 26 years were transplanted after myeloablative preparative regimens with either related bone marrow or cord blood (n=11) or unrelated cord blood (n=52), using cellcept and cyclosporine for GVHD prophylaxis. Cellcept and CSA were administered intravenously through the first 40–60 days post transplant using cellcept at a dose of 15mg/kg/dose IV q8H beginning on day -2 or -3 and CSA in traditional fashion targeting trough levels of 200–450 (infusion) and 150–350 with intermittent dosing. The patient then transitioned to oral therapy at the same dose and schedule until day 100–180 for cellcept and day 270 for cyclosporine and then tapered if no active GVHD was present. There were no acute toxicities attributable to cellcept observed in patients on IV or oral therapy. Despite the lack of steroids in the GVHD prophylactic regimen, all patients required treatment with antihypertensive therapy. Grossly, infection rates did not vary from those previously observed in conventionally treated patients at our center. The cumulative incidence (CINC) of neutrophil engraftment by day 42 was 79.4% (95% CI 64.7–91.2) which is comparable to previous reports. Two patients engrafted after a second unrelated cord blood transplant. Of the six patients who did not engraft, 3 died of infectious complications, two died of VOD and multi-system organ failure and one died of congenital pulmonary hypertension. Of the 59 patients evaluable for GVHD, follow-up ranged between 52 and 994 days (median 224 days). The CINC of acute GVHD grades II–IV by day 100 was 64.1% (95% CI 47.8–82.1) and the CINC of acute GVHD grades III– IV by day 100 was 6.3% (95% CI 0–17.0). Follow-up is too short to comment on the incidence of chronic GvHD, but to date, 5 of 14 patients followed for >100 days have developed mild chronic GvHD. The incidence of grade II acute GVHD was higher than that previously reported in pediatric patients receiving CSA/Pred while the incidence of grade III–IV GVHD was comparable. While this data is early, it appears that the incidence of acute Grade II GVHD is increased compared to previous series in patients treated with cellcept instead of Mtx (related bone marrow transplantation) or pred (unrelated cord blood transplantation). Engraftment in UCBT recipients was not compromised with the use of IV cellcept administered in the peritransplant period. Overall, despite the use of steroids to treat aGVHD, there was overall steroid sparing with this regimen. Additional patients will need to be tested with this regimen and longer follow-up is necessary to fully define the risks or benefits of this therapy.

Hepatitic pattern of graft versus host disease in children

Liver involvement by graft-versus-host disease (GVHD) is characterized histologically by bile duct damage, which may be severe. A different pattern, "hepatitic GVHD," has been described in adult patients. This pattern also shows marked lobular hepatitis and hepatocellular damage. We report the development of hepatitic GVHD in six pediatric patients. Clinical information and histologic features of liver biopsy samples were retrospectively reviewed. Patients' ages ranged from 3 to 11 years. Underlying diagnosis, pre-transplant conditioning and GVHD prophylaxis varied. Peripheral blood stem cells were the source of the allograft in four patients, matched sibling in one, and matched-unrelated donor in one. Hepatic GVHD was detected between 149 and 310 days post-transplant. Prior acute GVHD had developed in two patients, and involved the skin and/or gastrointestinal tract. No patients had significant ductopenia. Only one patient had significant lymphocytic infiltration of bile ducts (ductitis). Bile duct epithelial damage and significant portal/periportal inflammation were present in all patients. Lobular necro-inflammation was present in five patients. Five patients improved with immunosuppression and one died with progressive GVHD. This series focuses on hepatitic GVHD in pediatric patients. Clinical and histologic patterns are similar to what has been described in adults. Specific etiology and pathogenesis of this entity remain unclear.

Improved Immune Reconstitution with Low Incidence of Severe Graft-Versus-Host Disease after Transplantation of CD34+ or CD133+ Enriched Stem Cells with Add-Back of Ten Million T-Cells Per Kg.

Unrelated donors are commonly used for hematopoietic stem cell transplants, but graft-versus-host disease (GVHD) is a major problem. We investigated whether transplantation of CD34+ or CD133+ enriched stem cells with add-back of ten million T-cells per kg from unrelated donors would prevent acute GVHD in pediatric patients in combination with pharmacologic immunosuppression. Eighteen patients (1 CML in second chronic phase, 2 MDS, 4 ALL in CR1, 4 ALL in CR2, 1 JMML, 1 AML in CR1, 3 AML in CR2, 1 Wiskott-Aldrich syndrome and 1 NHL in CR2) were transplanted with G-CSF mobilized peripheral blood stem cells (PBSC) from HLA-matched unrelated donors (n = 18). Median of age was 8.9 years (0.5 to 18 years). Conditioning regimens were performed according to national therapy protocol guidelines. On the day of transplant patients received a median of 13.5 (4.5 to 30.0 x 106) CD34+ or CD133+ enriched stem cells and an aliquot of unmanipulated PBSC containing 10 x 106 T-cells per kg. GVHD prophylaxis consisted of cyclosporine A (CSA) and short course methotrexate (MTX) on day +1, +3 and +6. Engraftment was rapid with a median of 19.6 days in sixteen patients. Two patients failed to engraft at first. However, full donor chimerism and stable engraftment was achieved in both patients after cessation of CSA treatment and an additional stem cell boost without any reconditioning. One patient with ALL developed acute GVHD grade III (skin and gut) after cessation of CSA treatment, but responded well to treatment with CSA and steroids. None of the other 17 patients developed acute GVHD > grade I. Thirteen are alive and well with a median follow-up of 578 days (101 to 1095 days). Three patients died of severe infectious complications and two due to relapse (JMML, AML). Compared to a historical control group of patients transplanted with highly purified CD34+ selected cells, the group with add-back of 10 x 106 T-cells per kg showed significantly higher T-cell counts (p=0.008, Wilcoxon Rank sum test) on day 90 after transplantation with a median number of six T-cells/μl in the control group and a median number of 294 T-cells/μl in the study group. We conclude that add-back of 10 x 106 T-cells per kg in combination with CSA and short course MTX improves T-cell recovery and appears to be a safe T-cell dosage regarding acute GVHD in the setting of allogeneic peripheral blood stem cell transplantation from unrelated donors.

Dominant T-Cell Clonal Expansion Associated with Acute Graft-Versus-Host Disease after Allogeneic Hematopoietic Stem Cell Transplantation in Pediatric Patients.

Allogeneic hematopoietic stem cell transplantation (AHSCT) provides a valuable therapy for a variety of malignancies, solid tumors, hematological disorders and autoimmune diseases. One of the major complications in recipients after transplantation is graft-versus-host disease (GvHD), which can cause delayed T-cell reconstitution and therefore increase the risk of infection and mortality. It has been suggested that T cells play an important role in the development of GvHD. Several previous studies have identified T-cell clones associated with acute GvHD in adult patients. However, T-cell clonal expansion in the early stage of post-transplantation might also be caused by T-cells which are unrelated to acute GvHD. In this study, we used TCRβ CDR3 size spectratyping to detect T-cell clonal expansion among the polyclonal complexities of peripheral blood. We examined the TCRβ repertoire distribution at the onset of acute GvHD in 10 pediatric patients. We then compared that result with the TCRβ pattern at the same post-AHSCT stage in another 10 pediatric patients without acute GvHD.Method: An RT-PCR assay for Vβ CDR3 size distribution was performed. Each fluorescent PCR product was detected by an automated 310 DNA sequencer. The data were analyzed by GeneScan software.Results and Discussion: As expected, the TCRβ repertoire distribution was much skewed for all patients in both groups, because the immune suppression occurred at early stage of post-AHSCT. There were about 4–8 T-cell clones expanded in each patient for both groups. The TCRβ subfamilies among those clones varied significantly from patient to patient. However, Vβ2, Vβ9, Vβ13 and Vβ20 were commonly found in both groups, indicating in these cases that clonal expansion was not related to the occurrence of acute GvHD. Notably, TCR Vβ16 was found in 9 of 18 samples from 7 of 10 patients with acute GvHD. This TCR subfamily was not dominant in the patients without acute GvHD. This finding strongly suggests that the T-cell clone carrying TCR Vβ16 subfamily might be associated with acute GvHD in pediatric patients. The characterization of this T-cell clone is under study.

Transplantation of highly purified CD34+ progenitor cells from unrelated donors in pediatric leukemia

Unrelated donors are commonly used for hematopoietic stem cell transplants, but graft-versus-host disease (GVHD) is a major problem. We investigated whether transplantation of purified mobilized peripheral-blood CD34(+) stem cells from unrelated donors would prevent acute and chronic GVHD in pediatric patients with leukemia and avert the need for pharmacologic immunosuppression. Thirty-one pediatric patients with acute lymphoblastic leukemia (ALL, n = 16), acute myeloid (n = 7), chronic myeloid (n = 6), or juvenile myelomonocytic leukemia (n = 2) underwent transplantation. The median purity of CD34(+) cells after positive magnet-activated cell sorting was 98.5%. Patients received a median of 8.0 x 10(6) CD34(+) cells and 6 x 10(3) CD3(+) T lymphocytes per kilogram, with no posttransplantation pharmacologic immunosuppression. Primary acute GVHD > or = grade II was seen in only 10% of patients (n = 3) and occurred only after human herpesvirus 6 (HHV 6) infection. Two patients had limited chronic GVHD. Engraftment occurred in all patients (primary engraftment, n = 26; engraftment after reconditioning, n = 5). The 2-year survival estimate was 38% for all patients and 63% for patients with ALL in complete remission. Patients with myeloid malignancies had a poor outcome. In comparison to a historical control group who received unmanipulated bone marrow, our patients had a lower incidence of GVHD (P <.001). No difference was observed in the probability of relapse or survival. Study patients with ALL in remission showed a trend toward better survival (P =.07). Transplantation of purified peripheral-blood CD34(+) cells from unrelated donors effectively minimizes GVHD and may be a good therapeutic option for patients with relapsed ALL.