Effect of maturation at birth on the clinical features of neonatal cow's milk protein allergy: A retrospective study.

Neonatal immune regulation transitions from fetal immunity and varies with maturation status, but its role in neonatal cow's milk protein allergy (CMPA) remains unknown. We studied the association between maturation status at birth and neonatal CMPA. Clinical and laboratory data of neonates presenting with CMPA symptoms were retrospectively collected from two tertiary hospitals. Patients were assessed according to gestational age at birth: preterm, late-preterm, and full-term. Fifty-five infants (26 females, 14 preterm, 15 late-preterm, and 26 full-term) were included; 44 were negative for milk-specific immunoglobulin E. Neonatal CMPA was common during moderately premature periods. Preterm infants exhibited longer latency from initial CM exposure to disease onset, lower incidence of bloody stool, and absence of elevated monocyte counts. However, immunoreactivity to CM antigens was retained in all infants. Neonatal CMPA features varied with infant maturation status at birth. Our results improve the understanding of intestinal immunity development, fetal/neonatal immune regulation, and CMPA pathogenesis.

Antigen-specific T cell balance reveals Why patients with atopic dermatitis fail to achieve immune tolerance.

The number of regulatory T cells (Tregs) and how they behave in the pathogenesis of atopic dermatitis (AD) are still controversial. We identified and quantified Tregs, mite-specific Tregs, and mite-specific effector T cells (Teffs) in patients with AD and healthy controls (HCs). We collected peripheral blood and analyzed the cells using flow cytometry after stimulation with mite antigens. Mite-specific Tregs and mite-specific Teffs were recognized by the expression of CD137 and CD154, respectively. Patients with AD had more Tregs than HCs; however, when focusing on a single antigen, the ratio of mite-specific Tregs/Teffs was lower in patients with AD than in HCs. Furthermore, the mite-specific Teffs in patients with AD were more likely to produce proinflammatory cytokines interleukin (IL)-4 and IL-13. This Teff-dominant imbalance is thought to be the cause of development of atopic status in patients with AD without immune tolerance.

Assessment of Alcohol Exposure From Alcohol-Based Disinfectants Among Premature Infants in Neonatal Incubators in Japan.

Importance: The risk of premature infants in neonatal incubators exposed to evaporated alcohol from alcohol-based disinfectants (ABDs) is unknown. Objective: To assess alcohol concentrations in the peripheral blood of premature infants and neonatal incubators. Design, Setting, and Participants: A quality improvement study comparing 2 different populations before and after introduction of ABD practice (ABD-PRAC) was conducted in a neonatal intensive care unit of a single tertiary hospital in Japan. Participants included premature infants who were born before 34 weeks of gestational age and received medical care in neonatal incubators. The study consisted of 3 periods: (1) September 1, 2020, to August 1, 2021 (prospective observation of pre-ABD-PRAC, (2) August 2 to August 22, 2021 (introduction of ABD-PRAC to medical staff and parents in the neonatal intensive care unit), and (3) August 23, 2021, to March 31, 2022 (prospective observation of post-ABD-PRAC). No follow-up studies were initiated. Interventions: An ABD-PRAC that aimed to reduce alcohol evaporation from ABDs inside neonatal incubators was instituted: (1) place alcohol preps in the incubator just before use and remove them from the incubator as soon as possible and (2) withhold placing hands into the incubators until 60 seconds after using ABDs for disinfection (applied only to family members). Main Outcomes and Measures: Blood alcohol concentration and evaporated alcohol concentrations in neonatal incubators. Results: Disinfectant practice was assessed among 28 infants during the pre-ABD-PRAC (17 infants [10 girls]; median gestational age at birth, 29.4 [IQR, 26.3-30.3] weeks) and post-ABD-PRAC (11 infants [3 girls]; median gestational age at birth, 30.0 [IQR, 25.3-32.2] weeks) study periods. The median blood alcohol concentration was 7.0 (IQR, 5.4-9.3) mg/dL pre-ABD-PRAC and 4.2 (IQR, 2.5-7.2) mg/dL post-ABD-PRAC. The median evaporated alcohol concentration inside neonatal incubators during pre-ABD-PRAC during the day was 23.6 (IQR, 15.9-36.5) ppm and, at night, was 13.2 (IQR, 8.9-19.4) ppm; during post-ABD-PRAC, the concentration was 9.4 (IQR, 6.0-16.0) ppm during the day and 5.7 (IQR, 3.6-9.7) ppm at night. The introduction of ABD-PRAC at 22 weeks' corrected gestational age was associated with a lower blood alcohol concentration in premature infants: regression coefficient value, -8.3 (95% CI, -12.0 to -4.7). Conclusions and Relevance: In this study, alcohol evaporated from ABDs was absorbed by premature infants in neonatal incubators. The findings suggest that introduction of ABD-PRAC was associated with lower alcohol concentrations in neonatal incubators and in the blood of premature infants.

Recovery of lymphocyte subpopulations is incomplete in the long-term setting in pediatric solid tumor survivors.

BACKGROUND: Childhood cancer survivors (CCSs) may have comorbidities including a long-term abnormality in the immune system. Immune reconstitution in CCSs after treatment for acute leukemia has been reported previously, while analyses of immune reconstitution in CCSs with solid tumors have been limited. METHODS: Childhood cancer survivors who received chemotherapy for solid tumors and who visited University of Tsukuba Hospital between November 2019 and March 2021 were included the study. Peripheral blood was collected for flow cytometry analysis. RESULTS: Forty-nine samples from 35 CCSs (18 male, 17 female) were included in the study. High-dose chemotherapy and cerebral spinal irradiation were conducted in 14 CCSs (40%) and in five CCSs (14%), respectively. The median time between the completion of chemotherapy and the collection of the present samples was 15.0 months (range, 0-286 months). The total lymphocyte count, B cells, and CD8-positive T cells recovered to the normal range of controls (NR-CTLs) in 0 (0%), four (66.7%), and four (66.7%) of six samples at 0-3 months after the completion of chemotherapy, and in three (60%), four (80%), and three (60%) of five samples at 3-12 months after the completion of chemotherapy, respectively. Meanwhile, CD4-positive T cells remained lower than NR-CTLs in 0 (0%) of six samples, one (20%) of five samples, and seven (63.7%) of 11 samples at 0-3, 3-12 and 12-60 months after the completion of chemotherapy, respectively. CONCLUSIONS: Recovery to the NR-CTLs was rapidly achieved in B cells and CD8-positive T cells, while the recovery was slower and incomplete in CD4-positive T cells. Careful observation of infection in long-term follow-up clinics is needed.

Successful hematopoietic stem cell transplantation with reduced dose of busulfan for Omenn syndrome.

Omenn syndrome (OS) is typically observed in the autosomal recessive form of severe combined immunodeficiency (SCID) with autoreactive manifestations, and it requires allogeneic hematopoietic stem cell transplantation. Unlike non-OS SCID, a conditioning regimen is usually required to eradicate T-cells; however, optimal conditioning regimens are not established mainly because of the rarity of OS. Here, we report a case of hematopoietic stem cell transplantation with a reduced dose of busulfan, as a conditioning regimen and successful engraftment with complete chimerism. OS was diagnosed in a one-month-old boy based on a diffuse erythematous rash, absent B-cells, and activated T-cells. Genetic analysis failed to identify causative mutations for OS/SCID, such as RAG1/2. Bone marrow transplantation was performed from his HLA-matched sister with a conditioning regimen consisting of targeted busulfan, fludarabine, and anti-thymocyte globulin. Cyclosporine had been administered before transplantation to control abnormal T-cell activation and continued for graft-versus-host disease (GVHD) prophylaxis. Engraftment was achieved on day 12, and no GVHD symptoms were observed. For stem cell transplantation for OS, prior control of autoreactive symptoms with immunosuppressants is important for safe transplantation and reduced intensity conditioning (RIC) can be an option to achieve sustained engraftment.

CD300a blockade enhances efferocytosis by infiltrating myeloid cells and ameliorates neuronal deficit after ischemic stroke.

Immune responses contribute to tissue injury and repair during and after ischemic stroke. However, the spatiotemporal and initiating molecular events remain incompletely understood. Here, we show that mice deficient in the phosphatidylserine receptor CD300a, which is highly expressed on brain myeloid cells including Ly6Chi monocytes, exhibited ameliorated neurological deficit after middle cerebral artery occlusion (MCAO). CD300a inhibited signaling through the CD300b-DNAX-activation protein 12 (DAP12) signaling pathway to prevent efferocytosis of apoptotic cells. Deficiency of CD300a enhanced efferocytosis by myeloid cells infiltrating the brain as early as 1 hour after MCAO and reduced release of damage-associated molecular patterns from dead cells, resulting in milder inflammation in the penumbral region. Treatment with an anti-CD300a neutralizing antibody ameliorated the neurological deficit after MCAO. These findings reveal an important role of efferocytosis in the super-acute phase of ischemic stroke pathology and identified CD300a as a target for immunotherapy in treating ischemic stroke.

Nationwide survey of late-onset hemolysis in very low birthweight infants.

BACKGROUND: In Japan, some cases of late-onset acute hemolysis in very low birthweight (VLBW) infants have been reported. These cases had common features but the cause of hemolysis was unknown. The incidence and prognosis of this disease are also unknown. However, there are only few reports of such hemolytic episodes in countries other than Japan. Thus, this study aimed to examine the incidence and clinical course of late-onset acute hemolysis and to establish it as a new disease concept. METHODS: A nationwide prospective survey was conducted from 2011 to 2015 as a rare disease surveillance project of the Japan Society for Neonatal Health and Development. RESULTS: Twenty-four cases were confirmed. The median (range) gestational age, birthweight, and onset of hemolytic episodes were 26 weeks and 2 days (23 weeks and 4 days-31 weeks and 2 days), 898 g (627-1,416 g), and 19 days after birth (9-33 days), respectively. Phototherapy, blood transfusion, and exchange transfusion were required in 22 (96%), 24 (100%), and 7 (29%) cases, respectively. During the observation period, no recurrence of the hemolytic episode occurred. All patients survived; however, one case developed kernicterus and suffered severe neurological sequelae. CONCLUSIONS: In this study, at least 1 out of 1,259 VLBW infants developed hemolysis at 9-33 days after birth in Japan. Owing to the risk of kernicterus, this disease should be recognized as among the important pathological conditions of VLBW infants, suggesting the need to manage jaundice and anemia until 5 weeks after birth.

Identification and isolation of splenic tissue-resident macrophage sub-populations by flow cytometry.

Tissue-resident macrophages in the spleen, including red pulp and white pulp macrophages, marginal zone macrophages (MZMs) and marginal zone metallophilic macrophages (MMMs), are highly heterogeneous as a consequence of adaptation to tissue-specific environments. Each macrophage sub-population in the spleen is usually identified based on the localization, morphology and membrane antigen expression by immunohistochemistry. However, their phenotypical and functional characteristics remain incompletely understood due to the difficulty of identification and isolation by flow cytometry. We used a cocktail of three enzymes (Collagenase D, Dispase I and DNase I), rather than traditional mechanical grinding, for isolation of each sub-population, which resulted in significant improvement of isolation of these macrophage sub-populations, particularly MZMs and MMMs, as determined by CD11bhiF4/80medTim4hi and CD11bhiF4/80medTim4med, respectively. This method should be helpful for molecular and functional characterization of each splenic resident macrophage sub-population.

Marginal zone B cells exacerbate endotoxic shock via interleukin-6 secretion induced by Fcα/µR-coupled TLR4 signalling.

Marginal zone (MZ) B cells produce a first wave of antibodies for protection from blood-borne pathogens. However, the role of MZ B cells in inflammatory responses has not been elucidated. Here we show that MZ B cells produce pro-inflammatory cytokines, such as interleukin-6 (IL-6), and exacerbate systemic inflammatory responses to lipopolysaccharide (LPS). After intravenous injection of LPS or E. coli, mice deficient in MZ B cells or IL-6 only in MZ B cells have attenuated systemic inflammatory responses and prolonged survival compared with wild-type mice. LPS directly stimulates MZ B cells via Toll-like receptor 4 (TLR4) and MyD88 pathways for IL-6 production. Furthermore, TLR4 requires physical and functional association with Fcα/µR (CD351) for its oligomer formation, NF-κB signalling and IL-6 production from MZ B cells; this association is responsible for systemic inflammatory responses and endotoxic shock. These results reveal a pro-inflammatory role of MZ B cells in endotoxic shock.

Cord blood insulin-like growth factor (IGF)-1, IGF-binding proteins and adiponectin, and birth size in offspring of women with mild gestational diabetes.

OBJECTIVE: To clarify the impact of a mild form of gestational diabetes mellitus (GDM) on neonatal birth size, and on insulin-related hormones and adiponectin (AdipoQ) in cord blood. METHODS: Two hundred and sixteen Japanese pregnant women diagnosed as having normal glucose tolerance according to the JSOG criteria were enrolled. Of the 216 women, 38 women were reclassified into a mild GDM (mGDM) group according to the IADPSG criteria. Of the remaining 178 women, 135 women with normal 50-g glucose challenge test were reclassified into a normal glucose tolerance (NGT) group. Cord blood insulin-like growth factor (IGF)-1, IGF-binding proteins (IGFBPs) and AdipoQ were measured in the offspring of the two groups. RESULTS: Birth weight and its SD scores were larger in the mGDM group than in the NGT group. The incidence of large-for-gestational age (LGA) newborns was higher in the mGDM than in the NGT group. No differences in cord blood free IGF-1, IGFBP-1, IGFBP-2 or AdipoQ levels were observed between the mGDM and NGT groups. CONCLUSIONS: Our study suggests that mild GDM reclassified according to the IADPSG criteria influences neonatal birth size, but neither the IGF-IGFBP axis nor AdipoQ can account for the changes of birth size in offspring of women with mild GDM.

Transient myelofibrosis with autoimmune pancytopenia: a case report.

INTRODUCTION: Myelofibrosis associated with myelodysplasia is thought to herald poor prognosis in myelodysplastic syndrome (MDS). CASE REPORT: A 7-month-old boy presented with fever (39 degrees C), pancytopenia, and slight hepatosplenomegaly (3 and 2 cm, respectively). Bone marrow showed hypercellularity, hyperplasia of erythroblasts, and also myelofibrosis. IgG was 1,136 mg/dL, IgA was 131 mg/dL, and IgM was 89 mg/dL. Antinuclear and antineutrophil antibodies, red-blood-cell-associated IgG, antiplatelet antibodies, and Coombs test were positive. Karyotype was 46XY. No viral cause was evidenced. Mild myelodysplasia was revealed two months later, but was insufficient to support a diagnosis of MDS. The boy was treated with transfusion of packed cells, prednisolone 2 mg/kg/day for 3 weeks associated with intravenous gammaglobulin 400 mg/kg/day for 5 days. Direct Coombs remained positive 1 month after treatment for 5 months, myelofibrosis persisted for 3 months, and neutropenia for 21 months. After 3-year follow-up, hematological data were normal without any therapeutic intervention. CONCLUSION: Myelofibrosis associated with mild myelodysplasia and pancytopenia can have a benign evolution in infants and young children.