HLA-haploidentical stem cell transplantation in children with inherited bone marrow failure syndromes: A retrospective analysis on behalf of EBMT severe aplastic Anemia and pediatric diseases working parties

Haploidentical stem cell transplantation (haplo-SCT) represents the main alternative for children with inherited bone marrow failure syndrome (I-BMF) lacking a matched donor. This retrospective study, conducted on behalf of the EBMT SAAWP and PDWP, aims to report the current outcomes of haplo-SCT in I-BMFs, comparing the different in vivo and ex vivo T-cell depletion approaches. One hundred and sixty-two I-BMF patients who underwent haplo-SCT (median age 7.4 years) have been registered. Fanconi Anemia was the most represented diagnosis (70.1%). Based on different T-cell depletion (TCD) approaches, four categories were identified: (1) TCRαβ+/CD19+-depletion (43.8%); (2) T-repleted with post-transplant Cyclophosphamide (PTCy, 34.0%); (3) In-vivo T-depletion with ATG/alemtuzumab (14.8%); (4) CD34+ positive selection (7.4%). The cumulative incidences (CI) of neutrophil and platelet engraftment were 84% and 76% respectively, while that of primary and secondary graft failure was 10% and 8% respectively. The 100-day CI of acute GvHD grade III-IV(95% CI) was 13%, while the 24-month CI of extensive chronic GvHD was 4%. After a median follow-up of 43.4 months, the 2-year overall survival(OS) and GvHD/Rejection-free Survival (GRFS) probabilities are 67% and 53%, respectively. The TCR CD3+αβ+/CD19+ depletion group showed a significantly lower incidence of both acute and chronic GvHD and higher OS (79%; p0.013) and GRFS (71%; p < .001), while no significant differences in outcomes have been observed by different diagnosis and conditioning regimens. This large retrospective study supports the safety and feasibility of haplo-SCT in I-BMF patients. TCRαβ+/CD19+ depletion offers higher chances of patients' survival, with a significantly lower risk of severe a- and c-GvHD in I-BMFs compared to other platforms.

Long-Term Ovarian Function Assessment After Haematopoietic Stem Cell Transplantation in Female Sickle Cell Anaemia Survivors

BACKGROUND

Haematopoietic stem cell transplantation (HSCT) is a potentially curative treatment for sickle cell anaemia (SCA). While HSCT offers the possibility of disease remission, it can also lead to long-term complications, including gonadal dysfunction and premature menopause.

METHODS

We conducted a retrospective cohort study of female survivors who had hydroxyurea therapy and those who underwent post-HSCT follow-up for SCA at a teaching hospital in Lagos, Nigeria, between January 2019 and December 2022. Participants were eligible if they were at least five years post-HSCT or hydroxyurea treatment and had available serum samples for markers of ovarian function measurement. Demographic and clinical data were collected from the hospital register and patients' medical records. Serum levels of oestradiol, luteinizing hormone (LH), follicle-stimulating hormone (FSH), and anti-Müllerian hormone (AMH) were measured using the Abbott Architect i1000SR chemiluminescent immunoassay analyzer (Abbott Diagnostics, Abbott Park, IL). Descriptive statistics and inferential analyses were used to assess the relationship between markers of ovarian function (FSH and AMH) and clinical parameters.

RESULTS

There were statistically significant differences in the median serum levels of all the assessed endocrine hormones between the HSCT and non-HSCT (hydroxyurea) groups of SCA survivors. Up to 82.6% of the SCA survivors experienced ovarian dysfunction after HSCT treatment. Impaired ovarian function in SCA survivors was associated with a longer median follow-up duration than in SCA survivors who had normal ovarian function (12.0 vs. 7.5 years, p = 0.048). There were higher odds of impaired ovarian function in the SCA survivors who had myeloablative regimens than in those who had reduced intensity conditioning regimens (94.1% vs. 50.0%, p = 0.040).

CONCLUSION

Our study highlights the significant impact of HSCT on long-term ovarian function in female SCA survivors. However, further prospective studies with larger sample sizes and longer follow-up periods are required to confirm our findings and elucidate the factors influencing ovarian function in SCA survivors of HSCT. In addition, studies are also needed to further elucidate the optimal transplant protocols and fertility preservation strategies to minimize gonadal toxicity and preserve reproductive potential in female SCA patients undergoing HSCT.

Sirolimus-induced Hypertriglyceridemia Leads to Acute Pancreatitis and Diabetic Ketoacidosis Post Stem Cell Transplant for Sickle Cell Disease

Sirolimus (mammalian target of rapamycin inhibitor) is a potent immunosuppressive agent, used in patients receiving hematopoietic stem cell transplant (HSCT) for Graft vs Host disease prophylaxis. Compared to calcineurin inhibitors, sirolimus has no neurotoxicity or nephrotoxicity, but sirolimus causes dose-dependent thrombocytopenia, leukopenia, delayed wound healing, hyperlipidemia, and hypertriglyceridemia. Here we report a case of acute pancreatitis and diabetic ketoacidosis in a patient with sickle cell disease post haploidentical family donor HSCT which was managed conservatively without plasmapheresis. Based on our review of the literature, this is the first reported case of developing acute pancreatitis as an adverse effect of sirolimus-induced hypertriglyceridemia leading to diabetic ketoacidosis in a recipient of HSCT.

An International Survey of Allogeneic Hematopoietic Cell Transplantation for X-Linked Agammaglobulinemia

PURPOSE

X-linked agammaglobulinemia (XLA) is an inborn error of immunity caused by variants in Bruton's tyrosine kinase (BTK). XLA patients require lifelong immunoglobulin replacement therapy (IgRT). Only few XLA patients are indicated for allogeneic hematopoietic cell transplantation (HCT) because of severe complications. Accordingly, the published transplantation experience in XLA is minimal. We aimed to collect clinical data of XLA patients who received HCT in an international framework and to establish appropriate transplantation criteria and methods for XLA patients.

METHODS

XLA patients were recruited through a questionnaire and a literature review. The data are on patient characteristics and transplantation methods and outcomes.

RESULTS

In this study, twenty-two XLA patients who underwent HCT were recruited. The indication for HCT was recurrent or life-threatening infection in sixteen patients, malignancy in three, and other factors in three. A myeloablative conditioning, reduced toxicity myeloablative conditioning (RT-MAC), and reduced intensity conditioning (RIC) were selected in four, ten, and eight patients, respectively. Engraftment was achieved in 21 patients (95%). In all patients, 2-year overall survival (OS) and event-free survival (EFS) were 86% and 77%, respectively. In patients who received RT-MAC or RIC using treosulfan, busulfan, or melphalan, 2-year OS and EFS were 82% and 71%, respectively. Finally, twenty-one patients (95%) obtained complete or stable high-level mixed chimerism (50-95%), and the 1-year discontinuation rate of IgRT was 89%.

CONCLUSION

Based on the concept in which IgRT is the standard treatment for XLA, HCT may be an effective and safe alternative treatment option for XLA patients, and IgRT can be discontinued following transplantation. It is ideal to perform HCT in XLA patients for whom transplantation is indicated before they develop organ damage.

Obesity impairs cardiolipin-dependent mitophagy and therapeutic intercellular mitochondrial transfer ability of mesenchymal stem cells

Mesenchymal stem cell (MSC) transplantation alleviates metabolic defects in diseased recipient cells by intercellular mitochondrial transport (IMT). However, the effect of host metabolic conditions on IMT and thereby on the therapeutic efficacy of MSCs has largely remained unexplored. Here we found impaired mitophagy, and reduced IMT in MSCs derived from high-fat diet (HFD)-induced obese mouse (MSC-Ob). MSC-Ob failed to sequester their damaged mitochondria into LC3-dependent autophagosomes due to decrease in mitochondrial cardiolipin content, which we propose as a putative mitophagy receptor for LC3 in MSCs. Functionally, MSC-Ob exhibited diminished potential to rescue mitochondrial dysfunction and cell death in stress-induced airway epithelial cells. Pharmacological modulation of MSCs enhanced cardiolipin-dependent mitophagy and restored their IMT ability to airway epithelial cells. Therapeutically, these modulated MSCs attenuated features of allergic airway inflammation (AAI) in two independent mouse models by restoring healthy IMT. However, unmodulated MSC-Ob failed to do so. Notably, in human (h)MSCs, induced metabolic stress associated impaired cardiolipin-dependent mitophagy was restored upon pharmacological modulation. In summary, we have provided the first comprehensive molecular understanding of impaired mitophagy in obese-derived MSCs and highlight the importance of pharmacological modulation of these cells for therapeutic intervention. A MSCs obtained from (HFD)-induced obese mice (MSC-Ob) show underlying mitochondrial dysfunction with a concomitant decrease in cardiolipin content. These changes prevent LC3-cardiolipin interaction, thereby reducing dysfunctional mitochondria sequestration into LC3-autophagosomes and thus impaired mitophagy. The impaired mitophagy is associated with reduced intercellular mitochondrial transport (IMT) via tunneling nanotubes (TNTs) between MSC-Ob and epithelial cells in co-culture or in vivo. B Pyrroloquinoline quinone (PQQ) modulation in MSC-Ob restores mitochondrial health, cardiolipin content, and thereby sequestration of depolarized mitochondria into the autophagosomes to alleviate impaired mitophagy. Concomitantly, MSC-Ob shows restoration of mitochondrial health upon PQQ treatment (MSC-ObPQQ). During co-culture with epithelial cells or transplantation in vivo into the mice lungs, MSC-ObPQQ restores IMT and prevents epithelial cell death. C Upon transplantation in two independent allergic airway inflammatory mouse models, MSC-Ob failed to rescue the airway inflammation, hyperactivity, metabolic changes in epithelial cells. D PQQ modulated MSCs restored these metabolic defects and restored lung physiology and airway remodeling parameters.

Impact of Conditioning Regimen and Graft-versus-Host Disease Prophylaxis on The Outcome of Haploidentical Peripheral Blood Stem Cell Transplantation for High-Risk Severe Aplastic Anemia in Children and Young Adults: A Report from the Pediatric Severe Aplastic Anemia Consortium of India

Allogenic hematopoietic cell transplantation (HCT) is the best curative approach for patients with severe aplastic anemia (SAA). The outcomes of HCT from haploidentical family donors (HFDs) have improved, making it a feasible option for patients lacking an HLA-identical donor. However, data on HFD-HCT for younger patients with SAA is sparse. In this multicenter retrospective study, we evaluated the outcomes of 79 patients undergoing HFD-HCT for SAA. All the patients were heavily pretransfused, the median time to HCT was >12 months, and 67% had failed previous therapies. Conditioning was based on fludarabine (Flu)-cyclophosphamide (Cy)-antithymocyte globulin (ATG)/total body irradiation (TBI) with or without thiotepa/melphalan (TT/Mel). Post-transplantation Cy (PTCy) and calcineurin inhibitors (CNIs)/sirolimus were used as graft-versus-host disease (GVHD) prophylaxis with or without abatacept. The rate of primary graft failure (PGF) was 16.43% overall, lower in patients conditioned with TT/Mel. The incidences of acute and chronic GVHD were 26.4% and 18.9%, respectively. At a median follow-up of 48 months, the overall survival (OS) and event-free survival (EFS) were 61.6% and 58.1%, respectively. Both OS and EFS were better in the TT/Mel recipients and with abatacept as GVHD prophylaxis. On multivariate analysis, the use of abatacept was found to favorably impact the outcome variables, including GVHD and EFS. Our study suggests that PTCy-based HFD-HCT is a reasonable option for young patients with high-risk SAA, in whom optimization of conditioning and GVHD prophylaxis might further improve outcomes.

NSP4 and ORF9b of SARS-CoV-2 Induce Pro-Inflammatory Mitochondrial DNA Release in Inner Membrane-Derived Vesicles

Circulating cell-free mitochondrial DNA (cf-mtDNA) has been found in the plasma of severely ill COVID-19 patients and is now known as a strong predictor of mortality. However, the underlying mechanism of mtDNA release is unexplored. Here, we show a novel mechanism of SARS-CoV-2-mediated pro-inflammatory/pro-apoptotic mtDNA release and a rational therapeutic stem cell-based approach to mitigate these effects. We systematically screened the effects of 29 SARS-CoV-2 proteins on mitochondrial damage and cell death and found that NSP4 and ORF9b caused extensive mitochondrial structural changes, outer membrane macropore formation, and the release of inner membrane vesicles loaded with mtDNA. The macropore-forming ability of NSP4 was mediated through its interaction with BCL2 antagonist/killer (BAK), whereas ORF9b was found to inhibit the anti-apoptotic member of the BCL2 family protein myeloid cell leukemia-1 (MCL1) and induce inner membrane vesicle formation containing mtDNA. Knockdown of BAK and/or overexpression of MCL1 significantly reversed SARS-CoV-2-mediated mitochondrial damage. Therapeutically, we engineered human mesenchymal stem cells (MSCs) with a simultaneous knockdown of BAK and overexpression of MCL1 (MSCshBAK+MCL1) and named these cells IMAT-MSCs (intercellular mitochondrial transfer-assisted therapeutic MSCs). Upon co-culture with SARS-CoV-2-infected or NSP4/ORF9b-transduced airway epithelial cells, IMAT-MSCs displayed functional intercellular mitochondrial transfer (IMT) via tunneling nanotubes (TNTs). The mitochondrial donation by IMAT-MSCs attenuated the pro-inflammatory and pro-apoptotic mtDNA release from co-cultured epithelial cells. Our findings thus provide a new mechanistic basis for SARS-CoV-2-induced cell death and a novel therapeutic approach to engineering MSCs for the treatment of COVID-19.

Diagnosis and Management of Acquired Aplastic Anemia: Consensus Statement of Indian Academy of Pediatrics

JUSTIFICATION

In India, there is a lack of uniformity of treatment strategies for aplastic anemia (AA), and many children are managed only with supportive care due to non-availability of hematopoietic stem cell transplantation (HSCT).

PROCESS

Eminent national faculty members were invited to participate in the process of forming a consensus statement in Hyderabad in July, 2016. Draft guidelines were circulated to all members, and comments received in a online meeting in October, 2020 were incorporated into the final draft. These were approved by all experts.

OBJECTIVE

To facilitate appropriate management of children with acquired aplastic anemia.

RECOMMENDATIONS

Key recommendations are: i) A bone marrow biopsy is must to make a diagnosis of AA; ii) Rule out inherited bone marrow failure syndromes (IBMFS), connective tissue disorders, viral infections, paroxysmal nocturnal hemoglobinuria (PNH), drug or heavy metal induced marrow suppression in all cases of AA; iii) Conservative approach to transfusions should be followed, with a target to keep hemoglobin >6 g/dL in children with no co-morbidities; iv) HLA-matched sibling donor HSCT is the preferred choice of treatment for newly diagnosed very severe/ severe AA; v) In absence of HLA-matched family donor, a matched unrelated donor (MUD) transplant or immunosuppressive therapy (IST) should be considered as alternate choice based on physician expertise; vi) Fludarabine, cyclophos-phamide and anti-thymocyte globulin (ATG) based conditioning with cyclosporine and methotrexate as graft versus host disease (GvHD) prophylaxis is the preferred regimen; vii) Horse ATG and cyclosporine are the recommended drugs for IST. One should wait for 3-6 months for the response assessment and consideration of next line therapy.

Outcomes of COVID-19 in children with cancer – Report from the Indian Pediatric Oncology Group (InPOG) COVID-19 registry in India

Introduction

The clinical outcomes of COVID-19 infection in children with cancer have been variable worldwide. Therefore, we aimed to collect data from all regions in India through a national collaborative study and identify factors that cause mortality directly related to COVID-19 infection.

Methods

Data was collected prospectively on children across India on cancer therapy and diagnosed with COVID-19 infections from 47 centers from April 2020 to October 2021. Information was recorded on the demographics, the number of children that required intervention, and the outcome of the infection. In addition, we analyzed the impact of the delta variant in 2021.

Results

A total of 659 children were studied, of whom 64% were male and 36% were female. The data from the eastern region was sparse, and this was a collection bias. COVID-19 infection was predominantly seen in children less than five years. The delta variant had a higher impact in the southern region, and this was statistically significant. Of the 659 children, 30 children died (4.5%), however only 7 of the deaths were directly attributed to COVID-19 infection (1%).

Conclusion

The study reports the largest nationally representative cohort of children with cancer and COVID-19 to date in India. We identified demographic and clinical factors associated with increased all-cause mortality in patients with cancer. Complete characterization of the cohort has provided further insights into the effects of COVID-19 on cancer outcomes. The low mortality allows us to recommend that specific cancer treatments be continued without delays in therapy.

Pretransplant myeloid and immune suppression, reduced toxicity conditioning with posttransplant cyclophosphamide: Initial outcomes of novel approach for matched unrelated donor hematopoietic stem cell transplant for hemoglobinopathies

Hematopoietic stem cell transplant (HSCT) is currently the only curative option for thalassemia major (TM) and sickle cell disease (SCD). We report our experience of using pretransplant immune suppression (PTIS), augmented Johns Hopkins conditioning, and posttransplant cyclophosphamide (PTCy) as graft-versus-host disease (GvHD) prophylaxis for matched unrelated donor (MUD) transplant in TM/SCD. At a median follow-up of 307.5 days (range 251-395), all patients (three TM, one SCD) are alive and disease free. MUD HSCT with PTIS, augmented Johns Hopkins conditioning, and PTCy as GvHD prophylaxis is a promising way of treating patients with hemoglobinopathies with low regimen-related toxicity (RRT), no risk of graft failure (GF) and minimal GvHD rates.

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.

Barriers to cure for children with cancer in India and strategies to improve outcomes: a report by the Indian Pediatric Hematology Oncology Group

The survival of children with cancer in India is inferior to that of children in high-income countries. The Indian Pediatric Hematology Oncology Group (IPHOG) held a series of online meetings via www.Cure4kids.org to identify barriers to cure and develop strategies to improve outcomes. Five major hurdles were identified: delayed diagnosis, abandonment, sepsis, lack of co-operative groups, and relapse. Development of regional networks like IPHOG has allowed rapid identification of local causes of treatment failure for children with cancer in India and identification of strategies likely to improve care and outcomes in the participating centers. Next steps will include interventions to raise community awareness of childhood cancer, promote early diagnosis and referral, and reduce abandonment and toxic death at each center. Starting of fellowship programs in pediatric hemato-oncology, short training programs for pediatricians, publishing outcome data, formation of parent and patient support groups, choosing the right and effective treatment protocol, and setting up of bone marrow transplant services are some of the effective steps taken in the last decade, which needs to be supported further.

Hemophagocytic lymphohistiocytosis in infants: a single center experience from India

There is paucity of outcome data for hemophagocytic lymphohistiocytosis (HLH) in infants from India, especially post stem cell transplant (SCT). We report outcome data of eight infants diagnosed with HLH. Mean age was 7.1 months (range 2-11). Mutation analysis was possible in seven patients. One patient had Griscelli syndrome. In three patients, no known mutation could be identified, while in remaining three homozygous mutations in Perforin, Munc and STX11 gene were identified. All were treated as per HLH 2004 protocol. Four died during induction phase. One patient abandoned therapy. Two underwent SCT, while one is awaiting SCT. First patient is alive and disease-free at 22 months postmatched sibling donor SCT. Second underwent unrelated double cord blood transplant, but died 5 months posttransplant due to renal failure. It is feasible to offer SCT for infants with familial HLH in the developing world although barriers like sepsis and disease refractoriness remain.

Management of severe refractory thrombocytopenia in dengue hemorrhagic fever with intravenous anti-D immune globulin

Dengue hemorrhagic fever (DHF) is a potentially lethal complication of dengue fever due to shock and/or bleeding. Bleeding in DHF is due to thrombocytopenia and/or coagulopathy. The authors present their experience of usage of intravenous anti-D in 5 children with DHF and severe refractory thrombocytopenia (<10,000/mm(3)). It was administered in a dose of 50 to 75 μg/kg. Mean platelet count was 6800/mm(3) before and 33,600, 44,600, and 79,000/mm(3) after intravenous anti-D administration at 24, 48, and 72 hours, respectively. Average drop in hemoglobin after administration of anti-D was 2.28 g/dL. Intravenous anti-D can possibly be a treatment option for refractory thrombocytopenia in DHF.

Langerhans cell histiocytosis with digestive tract involvement

Gastrointestinal tract (GIT) involvement in Langerhans cell histiocytosis (LCH) is not commonly described. We present two children presenting with GIT involvement with LCH, one successfully treated on standard protocol and other being treated on a protocol for relapsed disease. A review of literature showed almost 95% children were less than 2 years of age and 62% were females. Vomiting, abdominal pain, constipation, intractable diarrhea, malabsorption, bloody stools, protein-losing enteropathy, and even intestinal perforation are some of the reported symptoms. More than 50% patients died within 18 months from diagnosis.

Control of massive bleeding in dengue hemorrhagic fever with severe thrombocytopenia by use of intravenous anti-D globulin

Dengue hemorrhagic fever (DHF) is a potentially lethal complication of mosquito borne viral disease, Dengue Fever. Thrombocytopenia is a constant finding in DHF/Dengue Shock Syndrome (DSS). We report two cases that fulfilled the WHO criteria of DSS: high fever, positive tourniquet test, severe thrombocytopenia (<10,000/mm(3)), hemo-concentration (Hematocrit increase >20%), hypotension and bleeding refractory to routine therapeutic measures, who showed dramatic improvement after receiving Intravenous Anti-D globulin (IV anti-D).