Successful Haploidentical Stem Cell Transplant With Posttransplant Cyclophosphamide for Hemophagocytic Lymphohistiocytosis

Haploidentical HSCT in the Treatment of Pediatric Hematological Disorders

Allogeneic hematopoietic stem cell transplantation has become a treatment option for otherwise non-curative conditions, both malignant and benign, affecting children and adults. Nevertheless, the latest research has been focusing extensively on transplantation from related and unrelated haploidentical donors, suitable for patients requiring emergent hematopoietic stem cell transplantation (HSCT) in the absence of an HLA-matched donor. Haploidentical HSCT (haplo-HSCT) can be an effective treatment for non-malignant pediatric disorders, such as primary immunodeficiencies or hemoglobinopathies, by enabling a much quicker selection of the appropriate donor for virtually all patients, low incidence of graft-versus-host disease (GVHD), and transplant-related mortality (TRM). Moreover, the outcomes of haplo-HSCT among children with hematological malignancies have improved radically. The most demanding tasks for clinicians are minimizing T-cell-mediated alloreactivity as well as early GVHD prevention. As a result, several T-cell depletion approaches, such as ex vivo T-cell depletion (TCD), and T-cell replete approaches, such as a combination of anti-thymocyte globulin (ATG), post-transplantation cyclophosphamide (PTCy), cyclosporine/tacrolimus, mycophenolate mofetil, or methotrexate, have been taken up. As more research is needed to establish the most beneficial form of therapy, haplo-HSCT is currently considered an alternative donor strategy for pediatric and adult patients with complications like viral and bacterial infections, invasive fungal disease, and GVHD.

Case report: Optimized ruxolitinib-based therapy in an infant with familial hemophagocytic lymphohistiocytosis type 3

Familial hemophagocytic lymphohistiocytosis (FHL) is a rare and fatal autosomal recessive immune disorder characterized by uncontrolled activation of T and NK cells, macrophages, and overproduction of inflammatory cytokines. Early hematopoietic cell transplantation (HCT) is required for long-term survival. Current therapy is based on the HLH-94/2004 protocol, but is insufficient to fully control disease activity. This case report describes an infant with FHL type 3 who, despite initial therapy with dexamethasone and etoposide, showed aberrant cytokine levels, including interleukin-18 (IL-18), chemokine ligand 9 (CXCL9), soluble interleukin-2 receptor (sIL-2R), and soluble tumor necrosis factor receptor type II (sTNF-RII). The Janus kinase inhibitor ruxolitinib was therefore coadministered. The patient was treated with dose-adjusted ruxolitinib guided by cytokine profiles, and was successfully prepared for HCT. The results demonstrate the effectiveness and safety of dose-adjusted ruxolitinib as a bridging therapy for FHL, and the value of monitoring cytokine levels, especially IL-18, CXCL9, sIL-2R, and sTNF-RII, as disease-activity markers for FHL.

Successful Salvage Haploidentical Bone Marrow Transplantation in a Child With Hemophagocytic Lymphohistiocytosis, When the Previously Matched Unrelated Donor Tested Positive for SARS-CoV-2 on the Day of Stem Cells Collection

The coronavirus disease 2019 pandemic has made us adjust our standards and cope with unpredictable circumstances affecting the whole world, including the medical field.

A 2-year-old boy diagnosed with X-linked lymphoproliferative disease type 2 with concomitant positive polymerase chain reaction test for Epstein-Barr virus–DNA was admitted to our transplant ward. His treatment scheme had to be modified at the last moment because of a donor disqualification due to a positive polymerase chain reaction result for severe acute respiratory syndrome coronavirus 2 just before the apheresis. We decided to perform salvage haploidentical bone marrow transplant from the patient's mother because it was the only possible option. Now, in a 5-month observation period after the hematopoietic stem cell transplantation, our patient is in good general condition. His case convinced us to redirect our approach to transplant procedure preparation. Following the European Group of Blood and Marrow Transplantation recommendations, we use cryopreserved apheresis materials to ensure the availability of stem cell products before the start of a conditioning regimen.

Haploidentical Stem Cell Transplant with Post-Transplant Cyclophosphamide in Pediatric Hemophagocytic Lymphohistiocytosis

PURPOSE

Primary hemophagocytic lymphohistiocytosis is a severe and uncommon disease affecting pediatric patients. Genetic abnormalities have been related to altered apoptosis and exaggerated inflammatory reactions. Chemoimmunotherapy and stem cell transplantation are treatment options, but transplant is the only curative treatment. Here we aim to describe the treatment with hematopoietic stem cell transplantation with a novel strategy and the outcomes.

METHODS

An observational, descriptive, case series study was performed in pediatric patients of two high complexity medical centers in Colombia. Data was collected retrospectively between 2015 and 2020.

RESULTS

We describe five pediatric cases with a diagnosis of primary hemophagocytic lymphohistiocytosis. All were treated with replete-cell haploidentical hematopoietic stem transplantation, reduced-intensity conditioning, and post-transplant cyclophosphamide, in two high-complexity centers in Colombia. All patients are alive, and one is receiving management for chronic graft-versus-host disease.

CONCLUSION

To the best of our knowledge, there are few reports in the literature with this strategy, promising a possible alternative when there are no other donor options.

Multicenter Outcome of Hematopoietic Stem Cell Transplantation for Primary Immune Deficiency Disorders in India

Background

Hematopoietic stem cell transplantation (HSCT) is the curative option for many primary immune deficiency disorders (PID). In the last 5 years, increased awareness, availability of diagnostics based on flow cytometry, genetic testing, improved supportive care, use of reduced toxicity conditioning, and success of haploidentical donor HSCT have improved access to HSCT for children with PID in India. We present results on children with PID who underwent HSCT across India and the factors that influenced outcome.

Patients and Methods

We collected retrospective data on the outcome of HSCT for PID from seven centers. We analyzed the impact of the type of PID, conditioning regimen, time period of HSCT- before or after January 2016, graft versus host disease prophylaxis, cause of mortality and overall survival.

Results

A total of 228 children underwent HSCT for PID at a median age of 12 months (range, 1 to 220 months) with a median follow up of 14.4 months. Infants accounted for 51.3% of the cohort and the male female ratio was 3:1. SCID (25%) and HLH (25%) were the more frequent diagnoses. Matched family donor was available in 36.4% and 44.3% children had a haploidentical HSCT. Reduced and myeloablative conditioning regimens were used with 64% children receiving a treosulfan based conditioning regimen. Peripheral blood stem cells were the predominant graft source at 69.3%. The survival in infants (60.2%) was inferior to children aged over 1 year (75.7% p value = 0.01). Children with Wiskott Aldrich syndrome (74.3%) and chronic granulomatous disease (82.6%) had the best outcomes. The survival was superior in children receiving HSCT from a matched sibling (78%) versus an alternate donor HSCT (61% p value = 0.04). In the cohort transplanted after January 2016 survival improved from 26.8% to 77.5% (p value = 0.00). Infection remains the main cause of mortality at in over 50% children. The 5-year overall survival rate was 68%.

Conclusion

Survival of children with PID undergoing HSCT in India has improved dramatically in last 5 years. Alternate donor HSCT is now feasible and has made a therapeutic option accessible to all children with PID.

Haploidentical stem cell transplantation with post-transplant cyclophosphamide for osteopetrosis and other nonmalignant diseases

Allogeneic hematopoietic stem cell transplantation (HSCT) is curative for a variety of nonmalignant disorders including osteopetrosis, bone marrow failures, and immune deficiencies. Haploidentical HSCT is a readily available option in the absence of a matched donor, but engraftment failure and other post-transplant complications are a concern. Post-transplant cyclophosphamide (PT-Cy) regimens are gaining popularity and recent reports show promising results. We report our experience with nine pediatric patients with nonmalignant diseases who were transplanted from a haploidentical donor with PT-Cy. From 2015 to 2019, nine children with nonmalignant diseases underwent haploidentical HSCT with PT-Cy, two as a second transplant and seven as primary grafts after upfront serotherapy and busulfan-based myeloablative conditioning. Patient’s diseases included osteopetrosis (n = 5), congenital amegakaryocytic thrombocytopenia (n = 2), hemophagocytic lymphohistiocytosis (n = 1), and Wiskott Aldrich syndrome (n = 1). Two patients failed to engraft following upfront PT-Cy transplants, one was salvaged with a second PT-Cy transplant, and the other with a CD34+ selected graft. None of the patients suffered from graft-versus-host disease. Three patients died from early posttransplant infectious complications and six patients are alive and well. In conclusion, haploidentical HSCT with PT-Cy is a feasible option for pediatric patients with nonmalignant diseases lacking a matched donor.

Treatment of pediatric primary hemophagocytic lymphohistiocytosis with the HLH-94/2004 regimens and hematopoietic stem cell transplantation in China

We aimed to clarify the clinical characteristics, prognostic factors, and effectiveness of the HLH-94/2004 regimens and hematopoietic stem cell transplantation (HSCT) in pediatric patients with primary hemophagocytic lymphohistiocytosis (pHLH) in China. A retrospective analysis was performed on 38 patients with pHLH at Beijing Children's Hospital. PRF1 (34.2%) and UNC13D (31.6%) were the most common mutations in the pHLH. Thirty-eight patients were treated with the HLH-94/2004 regimens after diagnosis. Twenty-six patients (72.2%) responded to first-line treatment (complete response: 55.5%, partial response: 16.7%). The median survival time was 23 months. The overall survival (OS) rate at 3 years was 74.7%. There was no significant difference in the response rate (72% vs. 63.6%, P = 0.703) or 3-year OS (83.6% vs. 66.7%, P = 0.443) between the patients treated with the HLH-94 regimen and those treated with the HLH-2004 regimen. The incidences of all side effects in patients treated with the HLH-94 or HLH-2004 regimen were 32.0% and 18.2%, respectively (P = 0.394). Among 15 patients treated with HSCT, neither the preconditioning regimen nor the donor type affected patient prognosis (P = 0.205 and P = 0.161, respectively). The disease status (remission or nonremission) before preconditioning did not affect prognosis or the incidence of GVHD. Furthermore, a higher bilirubin level (≥ 30 μmol/L) was correlated with a poorer prognosis in pHLH patients (P = 0.026). The effectiveness rates of the HLH-94 and HLH-2004 regimens, chemotherapy, and HSCT were similar in pHLH patients. A bilirubin level ≥ 30 μmol/L might be an adverse prognostic factor in pHLH.

Awareness of Hemophagocytic Lymphohistiocytosis as an Unusual Cause of Liver Failure in the Neonatal Period

BACKGROUND

Hemophagocytic lymphohistiocytosis (HLH) is a life-threatening syndrome that predominantly affects infants from birth to 18 months of age, characterized by fever and multiorgan failure. Liver injury has been rarely reported as a presenting sign in the neonatal period. This study reports a case with HLH in the neonatal period who presented with acute liver failure.

CASE PRESENTATION

Herein, a 3-day-old female newborn was admitted with cytopenia, increased liver enzymes, hypofibrinogenemia, and markedly elevated serum ferritin. Hemophagocytosis of bone marrow biopsy confirmed the diagnosis of HLH. The newborn was treated with HLH-2004 protocol, but she finally died from multiorgan failure.

CONCLUSION

Growing awareness of HLH as a cause of liver failure in the neonatal period can be associated with early treatment and reduces mortality in this group of patients.

Haemophagocytic lymphohisticytosis-an underrecognized hyperinflammatory syndrome

Haemophagocytic lymphohisticytosis (HLH) is a syndrome of uncontrolled, severe systemic inflammation (hyperinflammation) arising either from a genetic immune system defect [primary (pHLH)] or triggered as a complication of malignancy, infection, or rheumatologic disease [secondary (sHLH)]. Patients with HLH often have non-specific symptoms and become progressively and critically unwell, with fever, cytopenia and multi-organ failure. Untreated, HLH is almost universally fatal, but even when treated, mortality is high, particularly when HLH complicates malignancy. HLH is managed with immunosuppression, and this can seem difficult to justify in such unwell patients. This review aims to examine the diagnostic and treatment challenges posed by sHLH and to improve recognition among rheumatologists who, being expert in the management of multisystem diseases and in the use of immunosuppression, are ideally placed to deliver care and build an evidence base for better disease characterization and treatment.