Gaucher Disease Type 2 Manifested as Hemophagocytic Lymphohistiocytosis in a Neonate in the COVID-19 Era.

BACKGROUND: A term neonate presented with persistent severe thrombocytopenia, elevated liver enzymes, conjugated hyperbilirubinemia, hepatosplenomegaly, and mild hypotonia. OBSERVATIONS: A thorough workup for infections, congenital thrombocytopenias, and neonatal malignancies was negative. Because of increased anti-SARS-CoV-2 IgG antibodies after maternal COVID-19, multisystem inflammatory syndrome of neonates was considered and intravenous immunoglobulin was administered. The clinical condition of the neonate deteriorated and due to laboratory evidence of hyperinflammation, hemophagocytic lymphohistiocytosis was suspected, and treatment with etoposide and dexamethasone was initiated with temporary stabilization. Gaucher disease type 2 was eventually diagnosed. CONCLUSION: Gaucher disease can rarely present in neonates as hemophagocytic lymphohistiocytosis.

Development of a novel flow cytometry method for detecting pneumococcal-specific B cells.

Antigen-specific B cell identification by flow cytometry is crucial for investigating their immunophenotype, subset distribution, and kinetics post-infection or immunization. Methods using biotinylated polysaccharide antigens have been described, but there is still room for improvement regarding sensitivity and applicability. The aim of this study was the development and validation of a multimer bead-based method for detecting pneumococcal polysaccharide serotypes (PS)-specific B cells following pneumococcal immunization. PS was chemically biotinylated and mounted on anti-biotin beads, and labeled with phycoerythrin (PE)-conjugated anti-biotin antibody to form a PS-multimer used for cell staining. Labeled beads were washed to remove excess fluorochrome and diminish non-specific labeling and background noise. Optimal ratios of PS-bead conjugate to PE and PS-multimer to cells were determined with titration assays. Comparison between the PS-multimer and a PS-PE monomer revealed enhanced detection of PS-specific cells and considerable signal amplification, attributed to the multimeric form of the detection probe and increased availability of antigen epitopes. To validate the specificity of the method, a competition assay using unbound PS was performed. Following pre-incubation with increasing PS concentrations, detection of PS-specific B cells with the PS-multimer was inhibited in a stepwise manner. Pre-incubation with excess PS completely blocked the fluorescent signal. This novel bead-based flow cytometry approach is a sensitive method demonstrating high specificity. It generated enhanced signals, provided clear-cut results, and was easily applicable, not requiring B cell pre-enrichment. It could be modified to adapt other antigens of interest, especially polysaccharides and proteins that could be used to probe antigen-specific B cell responses. The study of such responses may elucidate the underlying mechanisms involved in the establishment of long-term protection, provide evidence-based rationale for improving currently available vaccines and vaccination strategies, and pave the way for future vaccine development.

Immunogenicity and Immunological Memory Induced by the 13-Valent Pneumococcal Conjugate Followed by the 23-Valent Polysaccharide Vaccine in HIV-Infected Adults.

Background: Vaccine-induced memory B-cell (MBC) subsets have distinct roles in the establishment of protective immunity; MBCs expressing nonswitched immunoglobulin M (IgM+ MBCs) replenish the MBC pool, whereas MBCs expressing isotype-switched immunoglobulin (sIg+ MBCs) differentiate into plasma cells upon antigen reencounter. We investigated immunogenicity and MBCs induced by combined 13-valent pneumococcal conjugate vaccine (PCV13) and 23-valent pneumococcal polysaccharide vaccine (PPV23) in human immunodeficiency virus (HIV)-infected adults. Methods: Forty HIV-seropositive adults receiving ART with undetectable viral loads were enrolled. Seventeen had a CD4+ T-cell count of ≥400 cells/µL (group A), and 23 had a CD4+ T-cell count of 200-399 cells/µL (group B). All adults received PCV13 and, 1 year later, PPV23. Levels of IgM+ MBCs (defined as polysaccharide [PS]-specific CD19+CD10-CD27+CD21++IgM+ MBCs) and sIg+ MBCs (defined as PS-specific CD19+CD10-CD27+CD21++IgM- MBCs) and antibodies against PS14 and PS3 were measured prior and 1 month after each vaccination. Results: Immunization caused a significant increase in PS antibodies, compared with levels at baseline (P < .001). Group B achieved significantly lower titers than group A (P < .05 for both PS14 and PS3). After receipt of PCV13, levels of IgM+ MBCs were unchanged, whereas levels of sIg+ MBCs increased significantly (P < .05 for PS14 and P < .001 for PS3). In contrast, following PPV23 receipt, levels of IgM+ MBCs were significantly reduced, and levels of sIg+ MBCs remained stable. A positive correlation was observed between baseline IgM+ and sIg+ MBC counts 1 month after PCV13 receipt but not after PPV23 receipt. Conclusions: PPV23 receipt 12 months after PCV13 receipt improved PCV13 immunogenicity. The reduction in the IgM+ MBC count observed after PPV23 receipt suggests that PPV23 has a depleting effect on PCV13-associated immunological memory. Clinical Trials Registration: NCT03041051.

Wiskott-Aldrich Syndrome Misdiagnosed as Immune Thrombocytopenic Purpura: A Case Report.

Wiskott-Aldrich syndrome (WAS) is a rare X-linked immunodeficiency characterized by various clinical phenotypes. We report the case of a 3-year-old immigrant boy presenting with persistent infant-onset thrombocytopenia treated for refractory immune thrombocytopenic purpura. Sequence analysis confirmed the diagnosis of WAS. The patient responded neither to IV infusions of immunoglobulin (Ig) nor a thrombopoietin receptor agonist and is currently planned for stem cell transplantation. Raised awareness is thus vital of this potentially misdiagnosed and lethal disorder. The diagnosis of WAS should be considered in all males with infant-onset immune thrombocytopenic purpura-like features, especially, if mean platelet volume is decreased (<7 fL) and good increment to platelet transfusions are evident.

Primary immunodeficiency diseases: a 30-year patient registry from the referral center for primary immunodeficiencies in Greece.

Primary Immunodeficiencies (PID) represent a group of heterogeneous immune diseases with important biological significance. We reviewed the records of children diagnosed with PID in the Referral Center for PID in our country in order to describe the epidemiological, clinical and laboratory characteristics of immunodeficient patients. During a 30-year period, 147 patients (101 males, 68.7 %), with a mean age of 6.5 years at the time of diagnosis, were diagnosed with PID. The most prevalent diagnoses of PID were: "Combined Immunodeficiency" in 46 (31.3 %) patients, "Well-defined immunodeficiency syndrome" in 35 (23.1 %) patients, "Predominantly antibody deficiency" in 30 (20.4 %) patients and "Congenital defect of phagocyte function or both" in 28 (19 %) patients. There was a higher prevalence of males with "Combined immunodeficiency" (p < 0.033) and "Predominantly antibody deficiency" (p < 0.02) compared to females. The median age of children at the onset of symptoms and at the time of diagnosis was 0.5y (IQR: 0.1-2.5) and 2y (IQR: 0.6-7.2), respectively. The median diagnostic delay was 0.9y (IQR: 0.2-4.8). This period was shorter for patients with "Combined immunodeficiency" [median 0.3y (IQR: 0.1-1)], and longer for those with "Predominantly antibody deficiency" [median 3.2y (IQR: 0.2-5.9) or "Disease of immune dysregulation" [median 3.2y (IQR: 0.1-6.6)]. Comparing the rates in our population with those of the European Registry (ESID), the rates of "Combined immunodeficiencies", "Well-defined syndromes" and "Congenital birth defects and/or function of phagocytes" were significantly higher in this study (p <0,001). PID registry analysis improves knowledge in the field of Immunology and enhances awareness, early detection, diagnosis, and management of this rare but significant group of diseases.

X-linked thrombocytopenia in three males with normal sized platelets due to novel WAS gene mutations.

The authors describe two young brothers and a 12-year-old male with long-standing thrombocytopenia with normal sized platelets, in whom novel mutations of the WAS gene were identified. Their clinical picture and the in vitro assessment of the T-cell function were consistent with X-linked thrombocytopenia (XLT). A high index of suspicion for XLT is required, even in the setting of normal sized platelets for males with affected maternally-related male family members, and males with moderately severe chronic thrombocytopenia that have failed to respond to treatments that are usually effective for immune thrombocytopenia.

The Divergent Effect of Different Infant Vaccination Schedules of the 13-Valent Pneumococcal Conjugate Vaccine on Serotype-Specific Immunological Memory.

Pneumococcal vaccination schedules are traditionally assessed based on the antibody response. The Memory B Cell (MBC) response has been less studied, despite its role in the magnitude and longevity of protection. We compared the immune response to different vaccination schedules with the 13-valent Pneumococcal Conjugate Vaccine (PCV13) and investigated the relationship between MBCs and the antibody response. Total and pneumococcal serotype (PS)-specific MBCs, their subsets and PS-specific IgG antibodies induced by a 3 + 0 (group A), 2 + 1 (group B) or 3 + 1 (group C) schedule in healthy infants were studied before and 1 month after the last PCV13. The relatively immature IgM+IgD+ MBC subset was the predominant subset in all groups but was larger in group A compared to group B and group C, indicating that age might be a significant parameter of the composition of the MBC pool. PS-specific MBCs at baseline were higher in group A, but they increased significantly only in the groups receiving the booster schedules (groups B and C). PS-specific IgM-only MBCs at baseline positively corelated with the antibody response and the PS-specific swIg MBCs post-immunization. Our findings illustrate the importance of a booster dose for the enrichment of PS-specific immunological memory. IgM-only MBCs and swIg MBCs may serve as additional correlates of vaccine-induced protection.

A Case Report of Salmonella enterica Meningitis in an Infant: A Rare Entity not to Forget.

INTRODUCTION: Salmonellae are gram-negative, facultatively anaerobic Enterobacteri-aceae consisting of two species, Salmonella enterica and Salmonella bongori. Invasive diseases, such as meningitis, result in hospitalization, short and long-term complications, and high mortality rates. CASE PRESENTATION: A 4-month-old baby girl was admitted to a district hospital because of diarrhea and fever. WBC count, urinalysis, urine cultures, and stool cultures were normal. She was treated with intravenous cefuroxime for 5 days. She was discharged on oral cefprozil for 5 days. After the end of therapy, she was admitted again to the same hospital with fever, diarrhea, vomits, and irri-tability. Cerebrospinal fluid examination revealed pleocytosis, while S. enterica was isolated. Em-pirical therapy with ceftriaxone, amikacin, and dexamethasone was started. Because of intracranial hypertension signs, she was transferred to the pediatric intensive care unit of our tertiary hospital. Therapy continued with intravenous ceftriaxone. Brain MRI revealed subarachnoid space dilata-tion. Increased head circumference and pulsating bregmatic fontanel led to a new cerebral MRI, in which ventricular dilatation and extraparenchymal subdural collection were noted. Ceftriaxone was changed to cefotaxime and ciprofloxacin was added. She remained clinically well; her brain MRI, a week later, showed marked improvement, and the course of intravenous antibiotics for 5 weeks was completed. Her baseline immunodeficiency screening tests were normal and repeat MRI two months post-treatment cessation did not reveal the previous abnormalities. CONCLUSION: Invasive Salmonella diseases, such as meningitis, are very uncommon in industrial countries nowadays, and the optimal management is yet not well established. Late onset of com-plications from Salmonella meningitis warrants more thorough neurodevelopmental follow-ups.

Immunogenicity, Immunological Memory and Monitoring of Disease Activity Following an Anamnestic Immunization With the 13-Valent Pneumococcal Conjugate Vaccine in Children With Idiopathic Nephrotic Syndrome.

Anamnestic 13-valent pneumococcal conjugate vaccine immunization did not affect the relapse risk in pediatric idiopathic nephrotic syndrome. Pneumococcal serotype (PS)-specific antibody titers increased significantly in all groups. Children receiving immunomodulatory treatments (IMTs) displayed significantly lower levels of PS-specific antibodies for 3/8 serotypes tested. PS-specific B-cell counts significantly increased only in healthy controls and patients receiving corticosteroids.

Flow cytometric analysis of the CD4+ TCR Vß repertoire in the peripheral blood of children with type 1 diabetes mellitus, systemic lupus erythematosus and age-matched healthy controls.

BACKGROUND: Data regarding the quantitative expression of TCR Vß subpopulations in children with autoimmune diseases provided interesting and sometimes conflicting results. The aim of the present study was to assess by comparative flow cytometric analysis the peripheral blood CD4+ TCR Vß repertoire of children with an organ-specific autoimmune disorder, such as type 1 diabetes mellitus (T1DM), in comparison to children with a systemic autoimmune disease, such as Systemic Lupus Erythematosus (SLE) in comparison to healthy age-matched controls of the same ethnic origin. The CD4+ TCR Vß repertoire was analysed by flow cytometry in three groups of participants: a) fifteen newly diagnosed children with T1DM (mean age: 9.2 ± 4.78 years old), b) nine newly diagnosed children with SLE, positive for ANA and anti-dsDNA, prior to treatment (mean age: 12.8 ±1.76 years old) and c) 31 healthy age-matched controls (mean age: 6.58 ± 3.65 years old), all of Hellenic origin. RESULTS: CD4 + TCR Vß abnormalities (± 3SD of controls) were observed mainly in SLE patients. Statistical analysis revealed that the CD4 + Vß4 chain was significantly increased in patients with T1DM (p < 0.001), whereas CD4 + Vß16 one was significantly increased in SLE patients (p < 0.001) compared to controls. CONCLUSIONS: CD4 + Vß4 and CD4 + Vß16 chains could be possibly involved in the cascade of events precipitating the pathogenesis of T1DM and SLE in children, respectively.

Chronic granulomatous disease: a 25-year patient registry based on a multistep diagnostic procedure, from the referral center for primary immunodeficiencies in Greece.

Chronic Granulomatous Disease (CGD) is an uncommon primary immunodeficiency caused by the absence or dysfunction of one of NADPH oxidase subunits, with heterogeneous genetic aetiologies. The aim of this study was the CGD patient registry in Greece, the identification of the responsible genotype and the potential correlation with the patient's clinical phenotype. Medical charts of 24 CGD patients, investigated by NBT test or DHR for NADPH oxidase activity, Western blot analysis for NADPH oxidase component expression and DNA sequencing (pyro- and cycle sequencing) for mutation analysis, were reviewed. All patients, but one, were classified into the different types of CGD. Sixteen patients from 14 unrelated families had X-linked CGD (66.7 %), four had mutations in the NCF1 gene (19 %), and three, from two unrelated families, had mutations in NCF2 (9.5 %) [Corrected]. Fifteen mutations were detected in the CYBB gene, including nonsense (53.8 %), splice site (30.8 %) and missense mutations (7.7 %), and deletions (7.7 %). Two novel mutations were identified; one in CYBB and one in NCF1. Carrier detection for X-CGD revealed that the de novo mutation rate was about 7 %. Prenatal diagnosis identified one affected male in three male fetuses tested. In both the X-linked and the autosomal recessive (AR-CGD) group, the gastrointestinal and respiratory manifestations were more common, followed by lympadenopathy in X-CGD and skin infections in the AR-CGD group. The patients with a mutation in CYBB had a wider variability of clinical manifestations and earlier diagnosis (4.6 years) compared to the AR-CGD group (12.9 years). The incidence of CGD in Greece is estimated at 0.90 (95 % CI 0.89-0.91) per 100,000 live births for the last decade.

SARS-CoV-2 mRNA Dual Immunization Induces Innate Transcriptional Signatures, Establishes T-Cell Memory and Coordinates the Recall Response.

BACKGROUND: mRNA vaccines have played a crucial role in controlling the SARS-CoV-2 global pandemic. However, the immunological mechanisms involved in the induction, magnitude and longevity of mRNA-vaccine-induced protective immunity are still unclear. METHODS: In our study, we used whole-RNA sequencing along with detailed immunophenotyping of antigen-specific T cells and humoral RBD-specific response to dual immunization with the Pfizer-BioNTech mRNA vaccine (BNT162b2) and correlated them with response to an additional dose, administered 10 months later, in order to comprehensively profile the immune response of healthy volunteers to BNT162b2. RESULTS: Primary dual immunization induced upregulation of the Type I interferon pathway and generated spike protein (S)-specific IFN-γ+ and TNF-α+ CD4 T cells, S-specific memory CD4 T cells, and RBD-specific antibodies against SARS-CoV-2. S-specific CD4 T cells induced by the primary series correlated with the RBD-specific antibody titers to a third dose. CONCLUSIONS: This study demonstrates the induction of both innate and adaptive immunity in response to the BNT162b2 mRNA vaccine in a coordinated manner and identifies the central role of primarily induced CD4+ T cells as a predictive biomarker of the magnitude of anamnestic immune response.

Ex Vivo Evaluation of Glutamine Treatment in Sepsis and Trauma in a Human Peripheral Blood Mononuclear Cells Model.

We aimed to assess the lipopolysaccharide (LPS), or heat shock (HS) induction, and glutamine-modulating effects on heat shock protein-90α (HSP90α) and cytokines in an ex vivo model using peripheral blood mononuclear cells (PBMCs). The PBMCs of patients with septic shock, trauma-related systemic inflammatory response syndrome (SIRS), and healthy subjects were incubated with 1 µg/mL LPS at 43 °C (HS). Glutamine 10 mM was added 1 hour before or after induction or not at all. We measured mRNA HSP90α, monocyte (m) and lymphocyte (l) HSP90α proteins, interleukin (IL)-1b, -6, -8, -10, tumor necrosis factor-α (TNF-α), and monocyte chemoattractant protein-1 (MCP-1) supernatant levels. Heat shock increased the HSP90α mRNA and mHSP90α in all groups (10-fold in sepsis, p < 0.001 and p = 0.047, respectively). LPS induced the mHSP90α and lHSP90α in healthy (p < 0.001) and mHSP90α in SIRS (p = 0.004) but not in sepsis. LPS induced the cytokines at 24 and 48 h in all groups, especially in trauma (p < 0.001); HS only induced the IL-8 in healthy (p = 0.003) and septic subjects (p = 0.05). Glutamine at 10 mM before or after stimulation did not alter any induction effect of LPS or HS on HSP90α mRNA and mHSP90α protein in sepsis. In SIRS, glutamine before LPS decreased the mHSP90α but increased it when given after HS (p = 0.018). Before or after LPS (p = 0.049) and before HS (p = 0.018), glutamine decreased the lHSP90α expression in sepsis but increased it in SIRS when given after HS (p = 0.003). Regarding cytokines, glutamine enhanced the LPS-induced MCP-1 at 48 h in healthy (p = 0.011), SIRS (p < 0.001), and sepsis (p = 0.006). In conclusion, glutamine at 10 mM, before or after LPS and HS, modulates mHSP90α and lHSP90α in sepsis and SIRS differently and unpredictably. Although it does not alter the stimulation effect on interleukins, glutamine enhances the LPS induction effect on supernatant MCP-1 in all groups. Future research should seek to elucidate better the impact of glutamine and temperature modulation on HSP90α and MCP-1 pathways in sepsis and trauma.

Receptor-Binding-Domain-Specific B Cell Responses Induced by mRNA Immunization against SARS-CoV-2.

mRNA vaccines have been instrumental in controlling the SARS-CoV-2 pandemic, but the short-lived protection mediated by Receptor Binding Domain (RBD)-specific antibodies necessitates frequent revaccinations to enhance vaccine-induced immunity. The development of RBD-specific B cell memory is critical for improving the qualitative and quantitative characteristics of the immune response. However, the effect of additional doses of mRNA vaccines on the composition of the RBD-specific B cell memory pool remains unclear. In this study, we found that dual BNT162b2 vaccination significantly increased both total RBD-specific and memory RBD-specific B cells and neutralizing antibodies. Following the second BNT162b2 dose, we showed a trend for the enrichment of CD27+IgM- memory RBD-specific B cells, which are known to correlate with a strong humoral response upon re-challenge. Repeated Measures Correlation (rmcorr) analysis revealed a significant correlation between antibody titers and both total and memory RBD-specific B cells, demonstrating that B cell and antibody responses are generated in a coordinated manner following BNT162b2 mRNA immunization. Our findings indicate that additional doses of the BNT162b2 mRNA vaccine enhance the qualitative and quantitative enrichment of the memory B cell pool against the vaccine antigens and collectively demonstrate the induction of a coordinated immune response to mRNA vaccination.

The Prognostic Effect of CDKN2A/2B Gene Deletions in Pediatric Acute Lymphoblastic Leukemia (ALL): Independent Prognostic Significance in BFM-Based Protocols.

One of the most frequent genes affected in pediatric ALL is the CDKN2A/2B gene, acting as a secondary cooperating event and playing an important role in cell-cycle regulation and chemosensitivity. Despite its inclusion in combined CNA (copy-number alterations) classifiers, like the IKZF1plus entity and the UKALL CNA profile, the prognostic impact of the individual gene deletions outside the context of a combined CNA evaluation remains controversial. Addressing the CDKN2A/2B deletions' additive prognostic effect in current risk-stratification algorithms, we present a retrospective study of a Greek pediatric ALL cohort comprising 247 patients studied over a 24-year period (2000-2023). Herein, we provide insight regarding the correlation with disease features, MRD clearance, and independent prognostic significance for this ALL cohort treated with contemporary BFM-based treatment protocols. Within an extended follow-up time of 135 months, the presence of the CDKN2A/2B deletions (biallelic or monoallelic) was associated with inferior EFS rates (65.1% compared to 91.8% for the gene non-deleted subgroup, p < 0.001), with the relapse rate accounting for 22.2% and 5.9%, respectively (p < 0.001). The presence of the biallelic deletion was associated with the worst outcomes (EFS 57.2% vs. 89.6% in the case of any other status, monoallelic or non-deleted, p < 0.001). Survival differences were demonstrated for B-ALL cases (EFS 65.3% vs. 93.6% for the non-deleted B-ALL subgroup, p < 0.001), but the prognostic effect was not statistically significant within the T-ALL cohort (EFS 64.3 vs. 69.2, p = 0.947). The presence of the CDKN2A/2B deletions clearly correlated with inferior outcomes within all protocol-defined risk groups (standard risk (SR): EFS 66.7% vs. 100%, p < 0.001, intermediate risk (IR): EFS 77.1% vs. 97.9%, p < 0.001, high risk (HR): EFS 42.1% vs. 70.5% p < 0.001 for deleted vs non-deleted cases in each patient risk group); additionally, in this study, the presence of the deletion differentiated prognosis within both MRD-positive and -negative subgroups on days 15 and 33 of induction. In multivariate analysis, the presence of the CDKN2A/2B deletions was the most important prognostic factor for relapse and overall survival, yielding a hazard ratio of 5.2 (95% confidence interval: 2.59-10.41, p < 0.001) and 5.96 (95% confidence interval: 2.97-11.95, p < 0.001), respectively, designating the alteration's independent prognostic significance in the context of modern risk stratification. The results of our study demonstrate that the presence of the CDKN2A/2B deletions can further stratify all existing risk groups, identifying patient subgroups with different outcomes. The above biallelic deletions could be incorporated into future risk-stratification algorithms, refining MRD-based stratification. In the era of targeted therapies, future prospective controlled clinical trials will further explore the possible use of cyclin-dependent kinase inhibitors (CDKIs) in CDKN2A/2B-affected ALL pediatric subgroups.

Is Rituximab-Associated Hypogammaglobulinemia Always Linked to B-Cell Depletion?

We describe a case of a 3-year-old male toddler with a history of severe and refractory warm antibody autoimmune hemolytic anemia (w-AIHA) since early infancy and hypogammaglobulinemia persisting 20 months after rituximab administration (second-line rescue therapy). Specifically, although peripheral blood flow cytometry B-cell population counts signified B-cell recovery following completion of rituximab therapy, IgG levels were barely detectable. Detailed laboratory evaluation did not reveal any humoral or cell-mediated immunity impairment and the patient remained asymptomatic, without any infections or recurrence of w-AIHA. Due to severe hypogammaglobulinemia, he was placed on immunoglobulin replacement therapy (IVIG). The implemented PID (primary immunodeficiency) gene panel identified only variants of uncertain significance (VUS). The aim of this report is to underline the documentation of persisting hypogammaglobulinemia after rituximab despite peripheral blood B-cell reconstitution.

Severe combined immunodeficiency in Greek children over a 20-year period: rarity of γc-chain deficiency (X-linked) type.

Severe combined immunodeficiencies (SCID) are a heterogeneous group of genetic disorders characterized by a blockade or impairment of both cellular and humoral immunity. Several epidemiological studies in different geographic areas have shown that the most common type of SCID affecting almost half of these patients is the X-linked common γ-chain (γ(c)) deficiency. The objective of the study was to document the incidence and types of SCID in our area. We conducted a retrospective analysis of patients who were diagnosed with SCID in the major immunology center in Greece for a 20-year period. During the study period, 30 children from 27 unrelated families with final diagnosis of SCID were identified. The incidence of SCID in Greece is estimated at 1.7 cases per 100,000 live births. Out of 30 children, 19 were boys (63.3%) and 26 (86.7%) had Greek maternal origin. Lymphocyte immunophenotypes that were identified were T(-)B(-)NK(+) in 12 (40%) children, T(-)B(+)NK(-) in six (20%), T(-)B(+)NK(+) in three (10%), T(-)B(-)NK(-) in two (6.7%) and T(+)B(+/-)NK(+) in seven (23.4%) (among them, four [13.4%] females with Omenn's syndrome). Molecular diagnosis was available for 12 children: γ(c) (2) with non Greek maternal origin, Jak3 (2), Rag1 (2), Artemis (3), ADA deficiency (2), PNP deficiency (1). Out of the 26 children of Greek maternal origin diagnosed with SCID representing 23 distinct families, only two (8.7%) had lymphocyte immunophenotype compatible with γ(c)-chain gene mutation (no molecular testing or enough DNA was available for them at the time of diagnosis). Findings of the present study suggest that, for unknown reasons, mutations of the γ(c) chain of several cytokine receptors have a rare occurrence in our area.

Copy Number Alteration Profile Provides Additional Prognostic Value for Acute Lymphoblastic Leukemia Patients Treated on BFM Protocols.

We present our data of a novel proposed CNA-profile risk-index, applied on a Greek ALLIC-BFM-treated cohort, aiming at further refining genomic risk-stratification. Eighty-five of 227 consecutively treated ALL patients were analyzed for the copy-number-status of eight genes (IKZF1/CDKN2A/2B/PAR1/BTG1/EBF1/PAX5/ETV6/RB1). Using the MLPA-assay, patients were stratified as: (1) Good-risk(GR)-CNA-profile (n = 51), with no deletion of IKZF1/CDKN2A/B/PAR1/BTG1/EBF1/PAX5/ETV6/RB1 or isolated deletions of ETV6/PAX5/BTG1 or ETV6 deletions with a single additional deletion of BTG1/PAX5/CDKN2A/B. (2) Poor-risk(PR)-CNA-profile (n = 34), with any deletion of ΙΚΖF1/PAR1/EBF1/RB1 or any other CΝΑ. With a median follow-up time of 49.9 months, EFS for GR-CNA-profile and PR-CNA-profile patients was 96.0% vs. 57.6% (p < 0.001). For IR-group and HR-group patients, EFS for the GR-CNA/PR-CNA subgroups was 100.0% vs. 60.0% (p < 0.001) and 88.2% vs. 55.6% (p = 0.047), respectively. Among FC-MRDd15 + patients (MRDd15 ≥ 10-4), EFS rates were 95.3% vs. 51.7% for GR-CNA/PR-CNA subjects (p < 0.001). Similarly, among FC-MRDd33 + patients (MRDd33 ≥ 10-4), EFS was 92.9% vs. 27.3% (p < 0.001) and for patients FC-MRDd33 - (MRDd33 < 10-4), EFS was 97.2% vs. 72.7% (p = 0.004), for GR-CNA/PR-CNA patients, respectively. In a multivariate analysis, the CNA-profile was the most important outcome predictor. In conclusion, the CNA-profile can establish a new genomic risk-index, identifying a distinct subgroup with increased relapse risk among the IR-group, as well as a subgroup of patients with superior prognosis among HR-patients. The CNA-profile is feasible in BFM-based protocols, further refining MRD-based risk-stratification.

Pneumocystis jirovecii pneumonia in a X-linked chronic granulomatous disease female carrier.

The X-chromosome linked (XL) female carriers of chronic granulomatous disease (CGD) are considered to have no risk for infection. Herein we present a female CGD XL-carrier who developed Pneumocystis jirovecii pneumonia and Serratia marcescens infection associated with age-related skewing of X-chromosome inactivation.