A Nationwide Study of GATA2 Deficiency in Italy Reveals Novel Symptoms and Genotype-phenotype Association.

GATA2 deficiency is a rare disorder encompassing a broadly variable phenotype and its clinical picture is continuously evolving. Since it was first described in 2011, up to 500 patients have been reported. Here, we describe a cohort of 31 Italian patients (26 families) with molecular diagnosis of GATA2 deficiency. Patients were recruited contacting all the Italian Association of Pediatric Hematology and Oncology (AIEOP) centers, the Hematology Department in their institution and Italian societies involved in the field of vascular anomalies, otorhinolaryngology, dermatology, infectious and respiratory diseases. Median age at the time of first manifestation, molecular diagnosis and last follow-up visit was 12.5 (age-range, 2-52 years), 18 (age-range, 7-64 years) and 22 years (age-range, 3-64), respectively. Infections (39%), hematological malignancies (23%) and undefined cytopenia (16%) were the most frequent symptoms at the onset of the disease. The majority of patients (55%) underwent hematopoietic stem cell transplantation. During the follow-up rarer manifestations emerged. The clinical penetrance was highly variable, with the coexistence of severely affected pediatric patients and asymptomatic adults in the same pedigree. Two individuals remained asymptomatic at the last follow-up visit. Our study highlights new (pilonidal cyst/sacrococcygeal fistula, cholangiocarcinoma and gastric adenocarcinoma) phenotypes and show that lymphedema may be associated with null/regulatory mutations. Countrywide studies providing long prospective follow-up are essential to unveil the exact burden of rarer manifestations and the natural history in GATA2 deficiency.

Absent B cells, agammaglobulinemia, and hypertrophic cardiomyopathy in folliculin-interacting protein 1 deficiency.

Agammaglobulinemia is the most profound primary antibody deficiency that can occur due to an early termination of B-cell development. We here investigated 3 novel patients, including the first known adult, from unrelated families with agammaglobulinemia, recurrent infections, and hypertrophic cardiomyopathy (HCM). Two of them also presented with intermittent or severe chronic neutropenia. We identified homozygous or compound-heterozygous variants in the gene for folliculin interacting protein 1 (FNIP1), leading to loss of the FNIP1 protein. B-cell metabolism, including mitochondrial numbers and activity and phosphatidylinositol 3-kinase/AKT pathway, was impaired. These defects recapitulated the Fnip1-/- animal model. Moreover, we identified either uniparental disomy or copy-number variants (CNVs) in 2 patients, expanding the variant spectrum of this novel inborn error of immunity. The results indicate that FNIP1 deficiency can be caused by complex genetic mechanisms and support the clinical utility of exome sequencing and CNV analysis in patients with broad phenotypes, including agammaglobulinemia and HCM. FNIP1 deficiency is a novel inborn error of immunity characterized by early and severe B-cell development defect, agammaglobulinemia, variable neutropenia, and HCM. Our findings elucidate a functional and relevant role of FNIP1 in B-cell development and metabolism and potentially neutrophil activity.

Successful sequential liver and hematopoietic stem cell transplantation in a patient with Fanconi anemia.

BACKGROUND: In Fanconi anemia bone marrow failure is the major cause of morbidity and mortality and hematopoietic stem cell transplantation represents the only curative treatment. Liver disease, in terms of elevated liver function tests, as well as benign and malignant liver tumors, occurs especially in case of androgen treatment. We report a unique case of a child with Fanconi anemia with FANCD2 mutation who developed neonatal cryptogenic liver cirrhosis and bone marrow failure. The child successfully underwent sequential liver transplantation and hematopoietic stem cell transplantation in the first 2 years of life. Nineteen months after hematopoietic stem cell transplantation and 30 months after liver transplantation, the patient is clinically well with normal hematopoietic function and excellent liver function. CONCLUSION: This is the first FA patient who successfully received sequential LT and HSCT highlighting that successful sequential transplantation is feasible in Fanconi anemia patients.

Diagnosis and management of neutropenia in children: The approach of the Study Group on Neutropenia and Marrow Failure Syndromes of the Pediatric Italian Hemato-Oncology Association (Associazione Italiana Emato-Oncologia Pediatrica - AIEOP).

Neutropenia refers to a group of diseases characterized by a reduction in neutrophil levels below the recommended age threshold. The present study aimed to review the diagnosis and management of neutropenia, including a diagnostic toolkit and candidate underlying genes. This study also aimed to review the progress toward the definition of autoimmune and idiopathic neutropenia rising in infancy or in late childhood but without remission, and provide suggestions for efficient diagnostics, including indications for the bone marrow and genetic testing. The management and treatment protocols for common and unique presentations are also reviewed, providing evidence tailored to a single patient.

A Novel Germline Mutation of ADA2 Gene in Two "Discordant" Homozygous Female Twins Affected by Adenosine Deaminase 2 Deficiency: Description of the Bone-Related Phenotype.

Adenosine Deaminase 2 Deficiency (DADA2) syndrome is a rare monogenic disorder prevalently linked to recessive inherited loss of function mutations in the ADA2/CECR1 gene. It consists of an immune systemic disease including autoinflammatory vasculopathies, with a frequent onset at infancy/early childhood age. DADA2 syndrome encompasses pleiotropic manifestations such as stroke, systemic vasculitis, hematologic alterations, and immunodeficiency. Although skeletal abnormalities have been reported in patients with this disease, clear information about skeletal health, with appropriate biochemical-clinical characterization/management, its evolution over time and any appropriate clinical management is still insufficient. In this paper, after a general introduction shortly reviewing the pathophysiology of Ada2 enzymatic protein, its potential role in bone health, we describe a case study of two 27 year-old DADA2 monozygotic female twins exhibiting bone mineral density and bone turnover rate abnormalities over the years of their clinical follow-up.

Hepatic focal nodular hyperplasia after pediatric hematopoietic stem cell transplantation: The impact of hormonal replacement therapy and iron overload.

BACKGROUND: The advent of techniques for the assessment of iron overload (liver T2*-MRI) has led to the awareness that focal nodular hyperplasia (FNH) represents a possible incidental finding after hematopoietic stem cell transplantation (HSCT), though its pathogenesis is still unclear. METHODS: We performed a retrospective analysis of the liver T2*-MRI scans performed between 2013 and 2018 in a single pediatric HSCT Unit and recorded the number of patients with FNH (group A). Patients incidentally diagnosed with FNH at imaging performed for different clinical indications were included in group B. RESULTS: Nine of 105 (8.6%) patients from group A were diagnosed with FNH. Group B included three patients. Overall, 12 patients were diagnosed 4.4 ± 3.1 years after HSCT. At univariate analysis, female gender (odds ratio [OR] 3.77, P = .03), moderate-to-severe iron overload (OR 6.97, P = .01), and hormone replacement therapy (HRT) administered for at least 6 months (OR 18.20, P = .0002) exposed patients to a higher risk of developing FNH. The detrimental effect of HRT was significant also at multivariate analysis (OR 7.93, P = .024). MRI-T2* values in affected patients were statistically lower than healthy controls (P < .001). CONCLUSIONS: We confirm the high incidence of FNH among transplanted pediatric patients and demonstrate the potential pathogenic role of HRT and iron overload.

Idiopathic neutropenia of infancy: Data from the Italian Neutropenia Registry.

Autoimmune neutropenia of infancy (AIN) is characterized by low risk of severe infection, tendency to spontaneously resolve and typically onset at ≤4-5 years of age; it is due to auto-antibodies whose detection is often difficult. In case of negativity of 4 antineutrophils autoantibody tests, after having excluded ethnic, postinfection, drug induced, or congenital neutropenia, according to the Italian guidelines the patients will be defined as affected by "idiopathic neutropenia" (IN). We describe the characteristics of 85 IN patients enrolled in the Italian neutropenia registry: they were compared with 336 children affected by AIN. The 2 groups were clinically very similar and the main differences were detection age (later in IN), length of disease (longer in IN) and, among recovered patients, age of spontaneous recovery: the median age at resolution was 2.13 years in AINs and 3.03 years in INs (P = .00002). At bivariate analysis among AIN patients earlier detection age (P = .00013), male sex (P = .000748), absence of leucopenia (P = .0045), and absence of monocytosis (P = .0419) were significantly associated with earlier recovery; in the IN group only detection age (P = .013) and absence of monocytosis (P = .0333) were significant. At multivariate analysis detection age and absence of monocytosis were independently significant (P = 6.7e-05 and 4.4e-03, respectively) in the AIN group, whereas in the IN group only detection age stayed significant (P = .013).

Diagnosis and management of acquired aplastic anemia in childhood. Guidelines from the Marrow Failure Study Group of the Pediatric Haemato-Oncology Italian Association (AIEOP).

Acquired aplastic anemia (AA) is a rare heterogeneous disease characterized by pancytopenia and hypoplastic bone marrow. The incidence is 2-3/million inhabitants/year, in Europe, but higher in East Asia. Survival in severe aplastic anemia (SAA) has markedly improved in the past 2 decades because of advances in hematopoietic stem cell transplantation, immunosuppressive and biologic drugs, and supportive care. In SAA hematopoietic stem cell transplant (HSCT) from a matched sibling donor (MSD) is the treatment of choice. If a MSD is not available, the options include immunosuppressive therapy (IST) or unrelated donor HSCT. The objective of this guideline is to provide healthcare professionals with clear guidance on the diagnosis and management of pediatric patients with AA. A preliminary, evidence-based document issued by a group of pediatric hematologists was discussed, modified and approved during a series of "Consensus Conferences" according to procedures previously validated by the AIEOP Board. The guidelines highlight the importance of referring pediatric patients with AA to pediatric centers with long experience in diagnosis, differential diagnosis, management, supportive care and follow-up of AA.

Minimal residual disease before and after transplantation for childhood acute lymphoblastic leukaemia: is there any room for intervention?

Eighty-two children and adolescents who underwent allogeneic transplantation for acute lymphoblastic leukaemia in remission (period 2001-2011, median follow-up 4·9 years) had been assessed for minimal residual disease (MRD) by real-time quantitative polymerase chain reaction before and at 1, 3, 6, 9 and 12 months after transplantation. Five-year event-free survival (EFS) and cumulative incidence of relapse were 77·7% [standard error (SE) 5·7] and 11·4% (SE 4·4), respectively, for patients with pre-transplant MRD <1 × 10(-4) (68%), versus 30·8% (SE 9·1; P < 0·001) and 61·5% (SE 9·5; P < 0·001), respectively, for those with MRD ≥1 × 10(-4) (32%). Pre-transplant MRD ≥1 × 10(-4) was associated with a 9·2-fold risk of relapse [95% confidence interval (CI) 3·54-23·88; P < 0·001] compared with patients with MRD <1 × 10(-4). Patients who received additional chemotherapy pre-transplant to reduce MRD had a fivefold reduction of risk of failure (hazard ratio 0·19, CI 0·05-0·70, P = 0·01). Patients who experienced MRD positivity post-transplant did not necessarily relapse (5-year EFS 40·3%, SE 9·3), but had a 2·5-fold risk of failure (CI 1·05-5·75; P = 0·04) if any MRD was detected in the first 100 d, which increased to 7·8-fold (CI 2·2-27·78; P = 0·002) if detected after 6 months. Anticipated immunosuppression-tapering according to MRD may have improved outcome, nevertheless all patients with post-transplant MRD ≥1 × 10(-3) ultimately relapsed, regardless of immunosuppression discontinuation or donor-lymphocyte-infusion. In conclusion, MRD before transplantation had the strongest impact on relapse and MRD positivity after transplantation, mostly if detected early and at low levels, did not necessarily imply relapse. Additional intensified chemotherapy and modulation of immunosuppression may reduce relapse risk and improve ultimate outcome.

Hematopoietic stem cell transplantation in thalassemia major and sickle cell disease: indications and management recommendations from an international expert panel.

Thalassemia major and sickle cell disease are the two most widely disseminated hereditary hemoglobinopathies in the world. The outlook for affected individuals has improved in recent years due to advances in medical management in the prevention and treatment of complications. However, hematopoietic stem cell transplantation is still the only available curative option. The use of hematopoietic stem cell transplantation has been increasing, and outcomes today have substantially improved compared with the past three decades. Current experience world-wide is that more than 90% of patients now survive hematopoietic stem cell transplantation and disease-free survival is around 80%. However, only a few controlled trials have been reported, and decisions on patient selection for hematopoietic stem cell transplantation and transplant management remain principally dependent on data from retrospective analyses and on the clinical experience of the transplant centers. This consensus document from the European Blood and Marrow Transplantation Inborn Error Working Party and the Paediatric Diseases Working Party aims to report new data and provide consensus-based recommendations on indications for hematopoietic stem cell transplantation and transplant management.

Safety and efficacy of narsoplimab in pediatric and adult patients with transplant-associated thrombotic microangiopathy: a real-world experience.

Transplant-associated thrombotic microangiopathy (TA-TMA) is a severe complication following hematopoietic stem cell transplantation (HSCT). No approved treatments are currently available. This study presents real-world data obtained with narsoplimab, a human immunoglobulin G4 monoclonal antibody that inhibits MASP-2, the effector enzyme of the lectin pathway of the complement system. Between January 2018 and August 2023, 20 (13 adult and 7 pediatric) patients diagnosed with TA-TMA received narsoplimab under an ongoing compassionate use program. The diagnosis was based on internationally defined criteria for pediatric and adult patients. Fifteen patients fulfilled the criteria recently established by an international consensus on TA-TMA. Nineteen patients exhibited high-risk characteristics. Thirteen patients (65%) responded to narsoplimab, achieving transfusion independence and significant clinical improvement. The one-hundred-day Overall Survival (OS) post-TA-TMA diagnosis was 70%, and 100% for responders. Narsoplimab proved to be effective and safe in the treatment of high-risk TA-TMA, with no increased infectious complications or other safety signals of concern across all age groups. The high response rates and the encouraging survival outcomes underscore the potential of narsoplimab as a valuable therapeutic option, particularly for high-risk cases.

Treosulfan vs busulfan conditioning for allogeneic bmt in children with nonmalignant disease: a randomized phase 2 trial.

Optimal conditioning prior to allogeneic hematopoietic stem cell transplantation for children with non-malignant diseases is subject of ongoing research. This prospective, randomized, phase 2 trial compared safety and efficacy of busulfan with treosulfan based preparative regimens. Children with non-malignant diseases received fludarabine and either intravenous (IV) busulfan (4.8 to 3.2 mg/kg/day) or IV treosulfan (10, 12, or 14 g/m2/day). Thiotepa administration (2 × 5 mg/kg) was at the investigator's discretion. Primary endpoint was freedom from transplantation (treatment)-related mortality (freedom from TRM), defined as death between Days -7 and +100. Overall, 101 patients (busulfan 50, treosulfan 51) with at least 12 months follow-up were analyzed. Freedom from TRM was 90.0% (95% CI: 78.2%, 96.7%) after busulfan and 100.0% (95% CI: 93.0%, 100.0%) after treosulfan. Secondary outcomes (transplantation-related mortality [12.0% versus 3.9%]) and overall survival (88.0% versus 96.1%) favored treosulfan. Graft failure was more common after treosulfan (n = 11), than after busulfan (n = 2) while all patients were rescued by second procedures except one busulfan patient. CTCAE Grade III adverse events were similar in both groups. This study confirmed treosulfan to be an excellent alternative to busulfan and can be safely used for conditioning treatment in children with non-malignant disease.

X-linked lymphoproliferative disease due to SAP/SH2D1A deficiency: a multicenter study on the manifestations, management and outcome of the disease.

X-linked lymphoproliferative disease (XLP1) is a rare immunodeficiency characterized by severe immune dysregulation and caused by mutations in the SH2D1A/SAP gene. Clinical manifestations are varied and include hemophagocytic lymphohistiocytosis (HLH), lymphoma and dysgammaglobulinemia, often triggered by Epstein-Barr virus infection. Historical data published before improved treatment regimens shows very poor outcome. We describe a large cohort of 91 genetically defined XLP1 patients collected from centers worldwide and report characteristics and outcome data for 43 patients receiving hematopoietic stem cell transplant (HSCT) and 48 untransplanted patients. The advent of better treatment strategies for HLH and malignancy has greatly reduced mortality for these patients, but HLH still remains the most severe feature of XLP1. Survival after allogeneic HSCT is 81.4% with good immune reconstitution in the large majority of patients and little evidence of posttransplant lymphoproliferative disease. However, survival falls to 50% in patients with HLH as a feature of disease. Untransplanted patients have an overall survival of 62.5% with the majority on immunoglobulin replacement therapy, but the outcome for those untransplanted after HLH is extremely poor (18.8%). HSCT should be undertaken in all patients with HLH, because outcome without transplant is extremely poor. The outcome of HSCT for other manifestations of XLP1 is very good, and if HSCT is not undertaken immediately, patients must be monitored closely for evidence of disease progression.

Iron Overload Following Hematopoietic Stem Cell Transplantation: Prevalence, Severity, and Management in Children and Adolescents with Malignant and Nonmalignant Diseases.

Iron overload (IOL) is a frequently reported complication following hematopoietic stem cell transplantation (HSCT) that has been investigated extensively in the field of hemoglobinopathies but has not been thoroughly characterized after HSCT in pediatric malignancies. Our aim was to assess prevalence, severity, risk factors, and management of IOL, as defined using biochemical (serum ferritin) and radiologic tools (T2*-weighted magnetic resonance imaging [MRI]), in a cohort of pediatric patients who underwent HSCT for either malignant or benign diseases. This monocentric, retrospective, observational study included all the 163 patients alive and in continuous remission at 24 months post-HSCT out of the 219 consecutive children and adolescents who underwent HSCT at our institution between 2012 and 2018, were included in the study. IOL was classified into 4 categories: absent, mild, moderate, and severe. Among the 163 patients, 73% had some degree of IOL (mild in 37%, moderate in 29%, and severe in 7%). Moderate/severe IOL was more frequent among patients diagnosed with a malignant disease versus those with a benign disease (43% versus 19%; P = .0065). Trend lines for serum ferritin showed a "bell-shaped" distribution, with the highest levels recorded during the first 6 months post-HSCT, followed by a spontaneous reduction. Both pre-HSCT (1659 ng/mL versus 617 ng/mL; P < .001) and maximum post-HSCT (2473 ng/mL versus 1591 ng/mL; P < .001) median ferritin levels were statistically higher in the patients with malignancies. Radiologic assessment of IOL confirmed a more severe degree in patients with malignant disorders compared to those with benign disorders (median T2*-MRI, 4.20 msec [interquartile range (IQR), 3.0 to 6.40 msec] versus 7.40 msec [IQR, 4.90 to 11.00 msec]; P = .008). T2* levels were associated with the number of transfusions performed (P = .0006), with a steeper drop in T2* values for the first 20 transfusions and a milder slope for subsequent transfusions. T2* and ferritin values showed a statistically significant negative exponential relationship (P < .0001), although a ferritin level ≥1000 ng/mL showed poor specificity (48%) and low positive predictive value (53%) for discriminating moderate-to-severe IOL from absent-mild IOL as assessed by T2*-MRI, but with high sensitivity (92%) and negative predictive value (91%). In a multivariable model, >20 transfusions (odds ratio [OR], 4.07; 95% confidence interval [CI], 1.61 to 10.68; P = .003) and higher pre-HSCT ferritin level (P < .001) were associated with the risk of developing moderate-to-severe IOL. Use of a sibling donor (OR, .29; 95% CI, .10 to .77; P = .015) and a nonmalignancy (OR, .27; 95% CI, .08 to .82; P = .026) were protective factors. Phlebotomy (66%), low-dose oral chelators (9%), or a combined approach (25%) were started at a median of 12 months after HSCT in 78% of the patients with IOL. Six percent of the patients treated exclusively with phlebotomy (median, 14, significantly higher in patients >40 kg) discontinued phlebotomy owing to poor venous access, lack of compliance, or hypotension, whereas 39% of patients treated with chelators developed mild renal or hepatic side effects that resolved after tapering or discontinuation. Patients with malignancies showed statistically higher pre-HSCT and post-HSCT ferritin levels and lower T2* values. High ferritin level recorded on T2*-MRI showed unsatisfactory diagnostic accuracy in predicting IOL; thus, T2*-MRI should be considered a key tool for confirming IOL after HSCT in patients with an elevated serum ferritin level. IOL treatment is feasible after HSCT.

The chemerin/CMKLR1 axis regulates intestinal graft-versus-host disease.

Gastrointestinal graft-versus-host disease (GvHD) is a major cause of mortality and morbidity following allogeneic bone marrow transplantation (allo-BMT). Chemerin is a chemotactic protein that recruits leukocytes to inflamed tissues by interacting with ChemR23/CMKLR1, a chemotactic receptor expressed by leukocytes, including macrophages. During acute GvHD, chemerin plasma levels were strongly increased in allo-BM-transplanted mice. The role of the chemerin/CMKLR1 axis in GvHD was investigated using Cmklr1-KO mice. WT mice transplanted with an allogeneic graft from Cmklr1-KO donors (t-KO) had worse survival and more severe GvHD. Histological analysis demonstrated that the gastrointestinal tract was the organ mostly affected by GvHD in t-KO mice. The severe colitis of t-KO mice was characterized by massive neutrophil infiltration and tissue damage associated with bacterial translocation and exacerbated inflammation. Similarly, Cmklr1-KO recipient mice showed increased intestinal pathology in both allogeneic transplant and dextran sulfate sodium-induced colitis. Notably, the adoptive transfer of WT monocytes into t-KO mice mitigated GvHD manifestations by decreasing gut inflammation and T cell activation. In patients, higher chemerin serum levels were predictive of GvHD development. Overall, these results suggest that CMKLR1/chemerin may be a protective pathway for the control of intestinal inflammation and tissue damage in GvHD.

Congenital and acquired neutropenias consensus guidelines on therapy and follow-up in childhood from the Neutropenia Committee of the Marrow Failure Syndrome Group of the AIEOP (Associazione Italiana Emato-Oncologia Pediatrica).

The management of congenital and acquired neutropenias presents some differences according to the type of the disease. Treatment with recombinant human granulocyte-colony stimulating factor (G-CSF) is not standardized and scanty data are available on the best schedule to apply. The frequency and the type of longitudinal controls in patients affected with neutropenias are not usually discussed in the literature. The Neutropenia Committee of the Marrow Failure Syndrome Group (MFSG) of the Associazione Italiana di Emato-Oncologia Pediatrica (AIEOP) elaborated this document following design and methodology formerly approved by the AIEOP board. The panel of experts reviewed the literature on the topic and participated in a conference producing a document that includes recommendations on neutropenia treatment and timing of follow-up.

Cytokine release syndrome after CAR infusion in pediatric patients with refractory/relapsed B-ALL: is there a role for diclofenac?

BACKGROUND: Cytokine release syndrome (CRS) is a major complication after chimeric-antigen receptor T-cell treatment, characterized by an uncontrolled systemic inflammatory reaction. We investigated the potential role of diclofenac in the management of CRS in five pediatric patients treated for relapsed/refractory B-lineage acute lymphoblastic leukemia. METHODS: In case of persistent fever with fever-free intervals shorter than 3 hours, diclofenac continuous infusion was initiated, at the starting dose of 0.5 mg/Kg/day, the lowest effective pediatric dose in our experience, possibly escalated up to 1 mg/Kg/day, as per institutional guidelines. RESULTS: CRS occurred at a median of 20 hours (range 8-27) after tisagenlecleucel infusion. Diclofenac was started at a median of 20 hours (range 13-33) after fever onset. A mean of 3.07 febrile peaks without diclofenac and 0.95 with diclofenac were reported (p = 0.02). Clinical benefit was achieved by hampering the progression of tachypnea and tachycardia. Despite fever control, CRS progressed in four of the five patients, and hypotension requiring vasopressors and fluid retention, as well as hypoxia, occurred. Vasopressors were followed by 1-2 doses of tocilizumab (one in patient 2 and two in patients 3, 4, and 5), plus steroids in patients 4 and 5. CONCLUSION: Based on a limited number of patients, diclofenac leads to better fever control, which translates into symptom relief and improvement of tachycardia, but could not prevent the progression of CRS.