Genotype and Phenotype of Adenosine Deaminase 2 Deficiency: a Report from Saudi Arabia.

Adenosine deaminase 2 deficiency (DADA2), a rare and potentially fatal systemic autoinflammatory disease, is characterized by low or lack of ADA2 activity due to ADA2 mutations. DADA2 symptoms are variable and include vasculitis, immunodeficiency, and cytopenia. Minimal data are available from Saudi Arabia. This retrospective study conducted at seven major tertiary medical centers examined the phenotypic and genotypic variabilities, clinical and diagnostic findings, and treatment outcomes among 20 Saudi patients with DADA2 from 14 families. The median age of the study cohort was 9.5 years (4-26 years). The clinical presentation was before the age of 5 months in 25% of patients. Homozygous c.1447-1451del mutation was the most frequent ADA2 alteration (40%), followed by c.882-2A:G (30%). All tested patients exhibited absent or near-absent ADA2 activity. Phenotypic manifestations included stroke (40%), hematological abnormalities (95%), lymphoproliferation (65%), and recurrent infection (45%). Five and three patients had extracranial vasculitis features and Hodgkin lymphoma, respectively. Atypical manifestations included growth retardation (30%) and transverse myelitis. Anti-tumor necrosis factor (anti-TNF) therapy was the main treatment. Some patients underwent blood transfusion, splenectomy, cyclosporine and colony-stimulating factor therapies, and hematopoietic stem cell transplantation due to anti-TNF therapy failure. Fulminant hepatitis and septic multiorgan failure caused mortality in three patients. Thus, this study revealed the variability in the molecular and clinical characteristics of DADA2 in the study cohort with predominant aberrant hematological and immunological characteristics. Consensus diagnostic criteria will facilitate early diagnosis and treatment. Additionally, disease registries or large prospective studies are needed for evaluating rare disease complications, such as cancer.

Neutrophil-to-Lymphocyte Ratio and Ferritin as Measurable Tools for Disease Burden and B Symptoms in Pediatric Patients With Hodgkin Lymphoma.

BACKGROUND: Pediatric Hodgkin lymphoma (HL) has been treated successfully with risk-adapted and response-adapted therapy. While risk factors like Ann Arbor staging system, B symptoms, bulky disease, and erythrocyte sedimentation rate were measured objectively, B symptoms are subjective tools. We evaluated whether the neutrophil-to-lymphocyte ratio (NLR) and inflammatory marker levels correlated with B symptoms and disease burden. MATERIALS AND METHODS: We conducted a retrospective chart review of all children ≤14 years old with pathology-confirmed HL treated at our institution. Data included clinical and pathologic features, pretreatment erythrocyte sedimentation rate, ferritin levels; monocyte, neutrophil, and lymphocyte counts; and NLR. Optimum cutoffs of variables significantly associated with B symptoms were determined based on receiver operating characteristic curves. RESULTS: Sixty-four patients were included in the analysis. Sixteen patients (25%) had B symptoms. Patients with B symptoms had higher ferritin levels (P<0.0001), monocyte counts (P=0.0060), neutrophil counts (P=0.0003) and NLR (P<0.0001), and lower lymphocyte counts (P=0.0017). Multiple receiver operating characteristic curves were generated to identify the optimum cutoff. Sensitivities and specificities of NLR (cutoff, 3.5) and ferritin (cutoff, 173 ng/mL) were the highest (81.25% and 81.25% [P<0.0001] and 89.36% and 75% [P<0.0001], respectively). Patients with NLR >3.5 and ferritin >173 (ng/mL) had significantly higher stage, bulky disease, and B symptoms. NLR and ferritin are not predictive of worst outcome in the cohort analyzed. CONCLUSIONS: NLR and ferritin levels were associated with high disease burden and B symptoms. Therefore, these variables can be used as measurable tools for B symptoms that can help stratify patients with HL. Larger and prospective studies are needed to validate these findings.

Lymphocyte subset at time of Epstein-Barr viremia post-allogeneic hematopoietic stem cell transplantation in children may predict development of post-transplant lymphoproliferative disease: CD8:CD20 ratio as a sensitive predictor.

EBV-associated PTLD following allogeneic HSCT is a serious complication associated with significant mortality. In this retrospective study, we evaluated whether lymphocyte subset numbers and CD8:CD20 ratio at time of EBV viremia in children undergoing allogeneic HSCT could predict development of PTLD. Absolute lymphocyte count, lymphocyte subsets, and CD8:CD20 ratio at the time of EBV viremia were analyzed. Patients who were treated preemptively with rituximab for high blood EBV viral load were excluded. Out of 266 patients transplanted during the study period, 26 patients were included in the analysis. Patients were divided into two cohorts; cohort 1 included patients with EBV-associated PTLD (n = 5; four with proven, one with probable PTLD). Cohort 2 included patients with EBV viremia without PTLD (n = 21). Lymphocyte recovery was slower in the PTLD group. CD8:CD20 ratio was significantly lower in the PTLD group (median 0.15) compared to the non-PTLD group (median 2.4, P = .012). Using the ROC curve and 1 as the cutoff value, CD8:CD20 ratios were analyzed. In the PTLD group, 4/5 patients (80%) had a ratio <1 whereas in the non-PTLD group, all 21 patients had a ratio >1. Sensitivity and specificity were 80% and 100%, respectively. Negative and PPVs were 95% and 100%, respectively. Profoundly low T-cell count and CD8:CD20 ratio may be used to predict development of PTLD in the context of EBV viremia in children post-allogeneic HSCT. Further studies are needed to validate this finding.

Hemophagocytic lymphohistiocytosis is a sign of poor outcome in pediatric Epstein-Barr virus-associated post-transplant lymphoproliferative disease after allogeneic hematopoietic stem cell transplantation.

EBV-related PTLD developing after HSCT is a potentially life-threatening disease. HLH is uncommon after allogeneic HSCT. Data on outcome of patients with PTLD and concomitant HLH after allogeneic HSCT are limited. In this retrospective study, we collected demographic, clinical, laboratory, and outcome data for 408 patients who underwent allogeneic HSCT from 2006 to 2015. Graft source included CB (n = 135; 33.1%), PBSCs (n = 34; 8.3%), and BM (n = 239; 58.6%). Eight out of 408 patients (2%) developed EBV-PTLD with a median age at HSCT of 5.9 years (range: 2.3-17.3). All eight patients received ATG as part of the conditioning regimen. Graft source was PBSC in three patients (37.5%), BM in four patients (50%), and CB in one patient (12.5%). Donors were matched unrelated in five patients (62.5%) and matched sibling in three patients (37.5%). Seven out of eight patients developed EBV-PTLD within the first 100-day post-HSCT. Lymph node biopsy revealed early lesions in three patients, polymorphic in three patients, and monomorphic PTLD in two patients. Three patients (37.5%) died within 1 month of EBV-PTLD diagnosis. All deceased patients developed HLH manifestations with two of them meeting HLH diagnostic criteria and one having an incomplete workup. PTLD after allogeneic HSCT with manifestations of HLH is associated with high mortality. Early identification and treatment of EBV-PTLD seems imperative to control the disease, especially if signs of HLH are evolving.

Gray Platelet Syndrome in a Neonate With VACTERL Association: A Novel Homozygous Pathogenic Variant c.5257C>T in the NBEAL2 Gene.

Gray platelet syndrome is a rare hereditary autosomal recessive condition distinguished by a mild to moderate propensity toward bleeding, moderate reduction in platelet count, and a significant decrease or complete absence of platelet alpha granules. VACTERL association is a condition of specific birth defects affecting multiple organ systems, with an unknown etiology. The acronym stands for vertebral anomalies (V), anal anomalies (A), cardiac anomalies (C), tracheoesophageal fistula (TE), renal anomalies or radial bone anomalies (R), and limb defects (L). To diagnose the VACTERL association, at least three of the aforementioned abnormalities should be present. This case report concerns a neonate born with a left absent thumb, a hypoplastic right thumb, an imperforate anus, and an atrial septal defect. During postoperative investigations, after addressing an anorectal malformation, the patient was found to have moderate thrombocytopenia and large gray platelets upon examination of a peripheral blood smear. A genetic analysis validated the pathogenic homozygous mutation c.5257C>T in the NBEAL2 gene, which corresponds to gray platelet syndrome.