Clinical and Treatment History of Patients with Partial DiGeorge Syndrome and Autoimmune Cytopenia at Multiple Centers.

BACKGROUND: Patients with partial DiGeorge syndrome (pDGS) can present with immune dysregulation, the most common being autoimmune cytopenia (AIC). There is a lack of consensus on the approach to type, combination, and timing of therapies for AIC in pDGS. Recognition of immune dysregulation early in pDGS clinical course may help individualize treatment and prevent adverse outcomes from chronic immune dysregulation. OBJECTIVES: Objectives of this study were to characterize the natural history, immune phenotype, and biomarkers in pDGS with AIC. METHODS: Data on clinical presentation, disease severity, immunological phenotype, treatment selection, and response for patients with pDGS with AIC were collected via retrospective chart review. Flow cytometric analysis was done to assess T and B cell subsets, including biomarkers of immune dysregulation. RESULTS: Twenty-nine patients with the diagnosis of pDGS and AIC were identified from 5 international institutions. Nineteen (62%) patients developed Evan's syndrome (ES) during their clinical course and twenty (69%) had antibody deficiency syndrome. These patients demonstrated expansion in T follicular helper cells, CD19hiCD21lo B cells, and double negative cells and reduction in CD4 naïve T cells and regulatory T cells. First-line treatment for 17/29 (59%) included corticosteroids and/or high-dose immunoglobulin replacement therapy. Other overlapping therapies included eltrombopag, rituximab, and T cell immunomodulators. CONCLUSIONS: AIC in pDGS is often refractory to conventional AIC treatment paradigms. Biomarkers may have utility for correlation with disease state and potentially even response to therapy. Immunomodulating therapies could be initiated early based on early immune phenotyping and biomarkers before the disease develops or significantly worsens.

Multicenter study of pediatric Epstein-Barr virus-negative monomorphic post solid organ transplant lymphoproliferative disorders.

BACKGROUND: Pediatric Epstein-Barr virus-negative monomorphic post solid organ transplant lymphoproliferative disorder [EBV(-)M-PTLD] comprises approximately 10% of M-PTLD. No large multi-institutional pediatric-specific reports on treatment and outcome are available. METHODS: A multi-institutional retrospective review of solid organ recipients diagnosed with EBV(-)M-PTLD aged ≤21 years between 2001 and 2020 in 12 centers in the United States and United Kingdom was performed, including demographics, staging, treatment, and outcomes data. RESULTS: Thirty-six patients were identified with EBV(-)M-PTLD. Twenty-three (63.9%) were male. Median age (range) at transplantation, diagnosis of EBV(-)M-PTLD, and interval from transplant to PTLD were 2.2 years (0.1-17), 14 years (3.0-20), and 8.5 years (0.6-18.3), respectively. Kidney (n = 17 [47.2%]) and heart (n = 13 [36.1%]) were the most commonly transplanted organs. Most were Murphy stage III (n = 25 [69.4%]). Lactate dehydrogenase was elevated in 22/34 (64.7%) and ≥2 times upper limit of normal in 11/34 (32.4%). Pathological diagnoses included diffuse large B-cell lymphoma (n = 31 [86.1%]) and B-non-Hodgkin lymphoma (B-NHL) not otherwise specified (NOS) (n = 5 [13.9%]). Of nine different regimens used, the most common were: pediatric mature B-NHL-specific regimen (n = 13 [36.1%]) and low-dose cyclophosphamide, prednisone, and rituximab (n = 9 [25%]). Median follow-up from diagnosis was 3.0 years (0.3-11.0 years). Three-year event-free survival (EFS) and overall survival (OS) were 64.8% and 79.9%, respectively. Of the seven deaths, six were from progressive disease. CONCLUSIONS: EFS and OS were comparable to pediatric EBV(+) PTLD, but inferior to mature B-NHL in immunocompetent pediatric patients. The wide range of therapeutic regimens used directs our work toward developing an active multi-institutional registry to design prospective studies. PLAIN LANGUAGE SUMMARY: Pediatric Epstein-Barr virus-negative monomorphic post solid organ transplant lymphoproliferative disorders (EBV(-)M-PTLD) have comparable outcomes to EBV(+) PTLD, but are inferior to diffuse large B-cell lymphoma in immunocompetent pediatric patients. The variety of treatment regimens used highlights the need to develop a pediatric PTLD registry to prospectively evaluate outcomes. The impact of treatment regimen on relapse risk could not be assessed because of small numbers. In the intensive pediatric B-non-Hodgkin lymphoma chemoimmunotherapy group, 11 of 13 patients remain alive in complete remission after 0.6 to 11 years.

Burkitt lymphoma after solid-organ transplant: Treatment and outcomes in the paediatric PTLD collaborative.

Burkitt lymphoma arising in paediatric post-solid-organ transplantation-Burkitt lymphoma (PSOT-BL) is a clinically aggressive malignancy and a rare form of post-transplant lymphoproliferative disorder (PTLD). We evaluated 35 patients diagnosed with PSOT-BL at 14 paediatric medical centres in the United States. Median age at organ transplantation was 2.0 years (range: 0.1-14) and age at PSOT-BL diagnosis was 8.0 years (range: 1-17). All but one patient had late onset of PSOT-BL (≥2 years post-transplant), with a median interval from transplant to PSOT-BL diagnosis of 4.0 years (range: 0.4-12). Heart (n = 18 [51.4%]) and liver (n = 13 [37.1%]) were the most frequently transplanted organs. No patients had loss of graft or treatment-related mortality. A variety of treatment regimens were used, led by intensive Burkitt lymphoma-specific French-American-British/Lymphomes Malins B (FAB/LMB), n = 13 (37.1%), and a low-intensity regimen consisting of cyclophosphamide, prednisone and rituximab (CPR) n = 12 (34.3%). Median follow-up was 6.7 years (range: 0.5-17). Three-year event-free and overall survival were 66.2% and 88.0%, respectively. Outcomes of PSOT-BL patients receiving BL-specific intensive regimens are comparable to reported BL outcomes in immunocompetent children. Multi-institutional collaboration is feasible and provides the basis of prospective data collection to determine the optimal treatment regimen for PSOT-BL.

Expanded phenotypic and hematologic abnormalities beyond bone marrow failure in MECOM-associated syndromes.

The MECOM gene encodes multiple protein isoforms that are essential for hematopoietic stem cell self-renewal and maintenance. Germline MECOM variants have been associated with congenital thrombocytopenia, radioulnar synostosis and bone marrow failure; however, the phenotypic spectrum of MECOM-associated syndromes continues to expand and novel pathogenic variants continue to be identified. We describe eight unrelated patients who add to the previously known phenotypes and genetic defects of MECOM-associated syndromes. As each subject presented with unique MECOM variants, the series failed to demonstrate clear genotype-to-phenotype correlation but may suggest a role for additional modifiers that affect gene expression and subsequent phenotype. Recognition of the expanded hematologic and non-hematologic clinical features allows for rapid molecular diagnosis, early identification of life-threatening complications, and improved genetic counseling for families. A centralized international publicly accessible database to share annotated MECOM variants would advance their clinical interpretation and provide a foundation to perform functional MECOM studies.

Burkitt Lymphoma After Cardiac Transplantation: Therapeutic Considerations.

Postsolid organ transplant Burkitt lymphoma (PSOT-BL) is rare but more aggressive than other post-transplant lymphoproliferative disorders (PTLD). Little is known about optimal treatment and outcome of postcardiac transplant Burkitt lymphoma (BL). We report an 8-year-old boy with a history of heart transplant who developed Epstein-Barr virus positive, late-onset PSOT-BL. He was successfully treated with BL specific chemoimmunotherapy and cessation of baseline immunosuppression. In this pediatric case of PSOT-BL, the use of standard intensive pediatric based chemoimmunotherapy regimen without modifications was feasible, well tolerated and resulted in complete remission. Long-term toxicities need further study.

Lymphoma in Partial DiGeorge Syndrome: Report of 2 Cases.

Primary immunodeficiency diseases are associated with an increased tendency for noninfectious complications of autoimmunity and malignancy, particularly leukemia and lymphoma. The mechanisms of immune dysregulation have been linked to the combination of dysregulated immune cells and environmental factors such as infections. In particular, dysfunction in T-cell subsets and Epstein-Barr virus contributes to the development of autoimmunity and lymphoproliferative disease in primary immunodeficiency diseases. There are scant reports of patients with partial DiGeorge syndrome and Epstein-Barr virus-driven lymphoma. We report 1 patients with partial DiGeorge syndrome who developed lymphoma, and review reported cases in the literature.

Two Clonally Distinct B-Cell Lymphomas Reveal the Diagnosis of XLP1 in a Male Child and His Asymptomatic Male Relatives: Case Report and Review of the Literature.

X-linked lymphoproliferative disease type 1 (XLP1) is a primary immunodeficiency disorder caused by pathogenic variants in the SH2D1A gene (SH2 domain containing protein 1A). Patients with XLP1 may present acutely with fulminant infectious mononucleosis, hemophagocytic lymphohistiocytosis, and/or B-cell non-Hodgkin lymphoma (B-NHL). We report a boy who developed 2 clonally distinct B-NHL 4 years apart and was found to have previously unrecognized XLP1. The report highlights the importance of clonal analysis and XLP1 testing in males with presumed late recurrences of B-NHL, and the role of allogeneic stem cell transplant (allo-SCT) in XLP1 patients and their affected male relatives.

Outcomes of adults and children with primary mediastinal B-cell lymphoma treated with dose-adjusted EPOCH-R.

Treatment with dose-adjusted EPOCH (etoposide, doxorubicin, cyclophosphamide, vincristine, prednisone) chemotherapy and rituximab (DA-EPOCH-R) has become the standard of care for primary mediastinal B-cell lymphoma (PMBCL) at many institutions despite limited data in the multi-centre setting. We report a large, multi-centre retrospective analysis of children and adults with PMBCL treated with DA-EPOCH-R to characterize outcomes and evaluate prognostic factors. We assessed 156 patients with PMBCL treated with DA-EPOCH-R across 24 academic centres, including 38 children and 118 adults. All patients received at least one cycle of DA-EPOCH-R. Radiation therapy was administered in 14·9% of patients. With median follow-up of 22·6 months, the estimated 3-year event-free survival (EFS) was 85·9% [95% confidence interval (CI) 80·3-91·5] and overall survival was 95·4% (95% CI 91·8-99·0). Outcomes were not statistically different between paediatric and adult patients. Thrombotic complications were reported in 28·2% of patients and were more common in paediatric patients (45·9% vs. 22·9%, P = 0·011). Seventy-five per cent of patients had a negative fluorodeoxyglucose positron emission tomography (FDG-PET) scan at the completion of DA-EPOCH-R, defined as Deauville score 1-3. Negative FDG-PET at end-of-therapy was associated with improved EFS (95·4% vs. 54·9%, P < 0·001). Our data support the use of DA-EPOCH-R for the treatment of PMBCL in children and adults. Patients with a positive end-of-therapy FDG-PET scan have an inferior outcome.

Variable expressivity and incomplete penetrance in a large family with non-classical Diamond-Blackfan anemia associated with ribosomal protein L11 splicing variant.

Diamond-Blackfan anemia (DBA) is a group of clinically and genetically heterogeneous bone marrow failure disorders with or without congenital anomalies. Variable expressivity and incomplete penetrance have been observed within affected families. Diamond-Blackfan anemia-7 (DBA7), caused by heterozygous mutations in ribosomal protein L11 (RPL11), accounts for approximately 5% of DBA. DBA7 is usually characterized by early-onset bone marrow failure often accompanied by congenital malformations, especially thumb defects. Here, we present the case of a 2-year-old boy with chronic mild normocytic anemia, short stature, bilateral underdevelopment of the thumbs, atrial septal defect, and hypospadias. Hematological testing revealed slightly decreased hematocrit and hemoglobin, normal HbF, and elevated eADA. Family history included maternal relatives with thumb defects, but the mother's thumbs were normal. Clinical exome sequencing detected a maternally-inherited RPL11 variant, c.396+3A>G, that is predicted to affect splicing. A family correlation study of the identified variant demonstrates segregation with thumb anomalies in the mother's family. RNA studies suggest that the variant produces an alternative transcript that is likely susceptible to nonsense-mediated decay. This report summarizes the prevalence of non-anemia findings in DBA7 and describes a non-classical familial presentation of DBA7 more associated with thumb anomalies than with anemia.

Acute Leukemia and Concurrent Mediastinal Germ Cell Tumor: Case Report and Literature Review.

There is a known association of primary nonseminomatous mediastinal germ cell tumors (NSMGCT) and hematologic malignancy in younger males not linked to treatment. When combined these two rare entities convey a very poor prognosis. Here we report a 16-year-old male with an anterior mediastinal mass diagnosed as a malignant germ cell tumor based on elevation of serologic markers. He was found to have acute leukemia with megakaryocytic differentiation several days later. We focus our report on the pathologic findings, including a review of the literature, and a novel molecular analysis of the germ cell tumor.

Pediatric B-Cell Lymphoma With Lymphoblastic Morphology, TdT Expression, MYC Rearrangement, and Features Overlapping With Burkitt Lymphoma.

Burkitt lymphoma (BL) and B-lymphoblastic lymphoma are subtypes of pediatric non-Hodgkin lymphoma with different presenting features, treatment, and outcomes. This case report documents a 5-year-old female who presented with B-cell lymphoma with lymphoblastic morphology, terminal deoxynucleotidyl transferase expression, MYC rearrangement, and features overlapping with BL. Genomic microarray analysis identified a gain on the long arm of chromosome 1 without other definitive changes. She was treated according to a BL protocol and remains in remission 16-months after initial diagnosis.