Hypogammaglobulinemia in Children After Hematopoietic Stem Cell Transplantation and Rituximab Treatment: Relevance of B Cell Subsets.

Rituximab (RTX) is widely employed to treat Epstein-Barr virus reactivation in children undergoing Hematopoietic Cell Transplantation (HCT). The resulting loss of B cells may cause persistent hypogammaglobulinemia. This retrospective cross-sectional study aims to identify flow cytometry biomarkers associated with persistent hypogammaglobulinemia in patients receiving RTX after HCT. We analyzed 5 patients (cases group) requiring immunoglobulin substitution due to low level of IgG (IgG <5 g/L) detected after RTX treatment and 5 patients (controls group) not requiring long-term immunoglobulin (Ig) substitution. We investigated the B cell reconstitution, and in patients group we observed a significantly lower count in B total, IgD+CD27+ marginal B cells and IgD-CD27+ switched-memory B cells, after a median of 5 years from HCT, compared with the control group. Despite the importance limits of our study and the heterogeneity of our data (age of included patients, time of evaluation, interval between RTX dose and assessment) we conclude that RTX given early after HCT might cause a deranged B cell maturation, contributing to the delation in B cell recovery following HCT, and switched memory and marginal zone B cell counts could be a promising biomarker to identify patients requiring long-term Ig substitution.

Neonatal Manifestations of Chronic Granulomatous Disease: MAS/HLH and Necrotizing Pneumonia as Unusual Phenotypes and Review of the Literature.

Chronic granulomatous disease (CGD) is a rare inborn error of immunity (IEI), characterized by a deficient phagocyte killing due to the inability of NADPH oxidase to produce reactive oxygen species in the phagosome. Patients with CGD suffer from severe and recurrent infections and chronic inflammatory disorders. Onset of CGD has been rarely reported in neonates and only as single case reports or small case series. We report here the cases of three newborns from two different kindreds, presenting with novel infectious and inflammatory phenotypes associated with CGD. A girl with CYBA deficiency presented with necrotizing pneumonia, requiring a prolonged antibiotic treatment and resulting in fibrotic pulmonary changes. From the second kindred, the first of two brothers developed a fatal Burkholderia multivorans sepsis and died at 24 days of life. His younger brother had a diagnosis of CYBB deficiency and presented with Macrophage Activation Syndrome/Hemophagocytic Lympho-Histiocytosis (MAS/HLH) without any infection, that could be controlled with steroids. We further report the findings of a review of the literature and show that the spectrum of microorganisms causing infections in neonates with CGD is similar to that of older patients, but the clinical manifestations are more diverse, especially those related to the inflammatory syndromes. Our findings extend the spectrum of the clinical presentation of CGD to include unusual neonatal phenotypes. The recognition of the very early, potentially life-threatening manifestations of CGD is crucial for a prompt diagnosis, improvement of survival and reduction of the risk of long-term sequelae.

Neonatal lymphocyte subpopulations analysis and maternal preterm premature rupture of membranes: a pilot study.

OBJECTIVES: Preterm premature rupture of membranes (pPROM) causes preterm delivery, and increases maternal T-cell response against the fetus. Fetal inflammatory response prompts maturation of the newborn's immunocompetent cells, and could be associated with unfavorable neonatal outcome. The aims were (1) to examine the effects of pPROM on the newborn's and mother's immune system and (2) to assess the predictive value of immune system changes in neonatal morbidity. METHODS: Mother-newborn pairs (18 mothers and 23 newborns) who experienced pPROM and controls (11 mothers and 14 newborns), were enrolled. Maternal and neonatal whole blood samples underwent flow cytometry to measure lymphocyte subpopulations. RESULTS: pPROM-newborns had fewer naïve CD4 T-cells, and more memory CD4 T-cells than control newborns. The effect was the same for increasing pPROM latency times before delivery. Gestational age and birth weight influenced maturation of the newborns' lymphocyte subpopulations and white blood cells, notably cytotoxic T-cells, regulatory T-cells, T-helper cells (absolute count), and CD4/CD8 ratio. Among morbidities, fewer naïve CD8 T-cells were found in bronchopulmonary dysplasia (BPD) (p=0.0009), and more T-helper cells in early onset sepsis (p=0.04). CONCLUSIONS: pPROM prompts maturation of the newborn's T-cell immune system secondary to antigenic stimulation, which correlates with pPROM latency. Maternal immunity to inflammatory conditions is associated with a decrease in non-major histocompatibility complex (MHC)-restricted cytotoxic cells.

Innate immunity ascertained from blood and tracheal aspirates of preterm newborn provides new clues for assessing bronchopulmonary dysplasia.

AIM: The study aimed to establish how granulocytes, monocytes and macrophages contribute to the development of bronchopulmonary dysplasia (BPD). MATERIALS AND METHODS: Study A: samples of blood and tracheal aspirates (TAs) collected from preterm newborn infants during the first 3 days of life were investigated by flow cytometry, and testing for white blood cells (WBCs), neutrophils and neutrophil extracellular traps (NETs). Maternal blood samples were also collected. Study B: data from previously-tested samples of TAs collected from preterm newborn infants were re-analyzed in the light of the findings in the new cohort. RESULTS: Study A: 39 preterm newborn infants were studied. A moderate correlation emerged between maternal WBCs and neutrophils and those of their newborn in the first 3 days of life. WBCs and neutrophils correlated in the newborn during the first 8 days of life. Decision rules based on birth weight (BW) and gestational age (GA) can be used to predict bronchopulmonary dysplasia (BPD). Neutrophil levels were lower in the TAs from the newborn with the lowest GAs and BWs. Study B: after removing the effect of GA on BPD development, previously-tested newborn were matched by GA. Monocyte phenotype 1 (Mon1) levels were lower in the blood of newborn with BPD, associated with a higher ratio of Monocyte phenotype 3 (Mon3) to Mon1. Newborn infants from mothers with histological chorioamnionitis (HCA) had lower levels of classically-activated macrophages (M1) and higher levels of alternatively-activated macrophages (M2) in their TAs than newborn infants from healthy mothers. CONCLUSION: Immune cell behavior in preterm newborn infants was examined in detail. Surprisingly, neutrophil levels were lower in TAs from the newborn with the lowest GA and BW, and no correlation emerged between the neutrophil and NET levels in TAs and the other variables measured. Interestingly, monocyte phenotype seemed to influence the onset of BPD. The rise in the ratio of Mon 3 to Mon 1 could contribute to endothelial dysfunction in BPD.

A 4-MicroRNA signature can discriminate primary lymphomas from anaplastic carcinomas in thyroid cytology smears.

BACKGROUND: Anaplastic thyroid carcinoma (ATC) and primary thyroid lymphoma (PTL) are uncommon tumors of the thyroid gland with several overlapping clinical and pathologic features that may render their differentiation difficult in fine-needle aspiration (FNA) cytology. MicroRNA (miRNA) signatures have been recently reported as useful diagnostic tools applied to cytology specimens. METHODS: Smears of 23 ATCs, 14 PTLs, and 20 non-neoplastic materials with multinodular goiter (MNG) were retrieved and classified based on their cytologic features and flow cytometric profiles. The ATC-related expression of hsa-miR-26a, hsa-miR-146b, hsa-miR-221, and hsa-miR-222 was quantified using quantitative reverse transcriptase-polymerase chain reaction analysis. RESULTS: All miRNAs were remarkably up-regulated in ATC samples compared with PTL samples (P < .01). Moreover, expression levels of hsa-miR-146b, hsa-miR-221, and hsa-miR-222 were significantly higher in ATCs than in MNG samples (P < .01). Significant down-regulation of hsa-miR-26a was observed in PTLs compared with MNG samples, whereas hsa-miR-146b was overexpressed. Receiver operating characteristic analysis was used to determine the optimal cutoff for distinguishing ATC from PTL. The estimated receiver operating characteristic thresholds displayed a sensitivity level greater than 0.80 in achieving a diagnosis of PTL, allowing the correct identification of 13 of 14 PTL samples (93%). CONCLUSIONS: Histotype-specific miRNA signatures can provide new insight into the molecular mechanisms of thyroid carcinogenesis. The tested 4-miRNA signature is a promising diagnostic tool for differentiating ATC from PTL and non-neoplastic MNG, even in the presence of scant material obtained from minimally invasive procedures.