A Japanese retrospective study of non-tuberculous mycobacterial infection in children, adolescents, and young adult patients with hematologic-oncologic diseases.

Non-tuberculous mycobacterial infection (NTM) is rare in healthy children, with lymphadenitis being the most common presentation. Immunocompromised populations are known to be at high risk, but the clinical picture of NTM infection in pediatric hematology/oncology patients is unclear. In this nationwide retrospective analysis of patients under the age of 40 treated in Japanese pediatric hematology/oncology departments who developed NTM infection between January 2010 and December 2020, 36 patients (21 patients with hematopoietic stem cell transplantation (HSCT) and 15 nontransplant patients) were identified. Post-transplant patients were infected with NTM at 24 sites, including the lungs (n = 12), skin and soft tissues (n = 6), bloodstream (n = 4), and others (n = 2). Nine of twelve patients with pulmonary NTM infection had a history of pulmonary graft-versus-host disease (GVHD), and rapid-growing mycobacteria (RGM) were isolated from five of them. In nontransplant patients, the primary diseases were acute lymphoblastic leukemia (ALL; n = 5), inborn errors of immunity (IEI; n = 6), and others (n = 4). All cases of ALL had bloodstream infections with RGM, whereas all cases of IEI were infected with slow-growing mycobacteria (SGM). In summary, three typical clinical scenarios for pediatric hematology/oncology patients have been established: RGM-induced pulmonary disease in patients with pulmonary GVHD, RGM bloodstream infection in patients with ALL, and SGM infection in patients with IEI. Our findings suggest that NTM must be regarded as a pathogen for infections in these high-risk patients, especially those with pulmonary GVHD, who may require active screening for NTM.

Juvenile Hemochromatosis With Non-transfused Hemolytic Anemia Caused by a De Novo PIEZO1 Gene Mutation.

Differential diagnosis of juvenile hemochromatosis along with hemolytic anemia is often difficult. We report a 23-year-old woman with macrocytic hemolytic anemia with iron overload. The patient showed high serum ferritin and transferrin saturation and low serum transferrin and ceruloplasmin. We also noticed stomatocytes in her blood smear, which was confirmed by scanning electron microscopy. Target gene sequencing identified a mutation in PIEZO1 (heterozygous c.6008C>A: p.A2003D). This mutation was reported previously in a family with dehydrated hereditary stomatocytosis (DHS1, [OMIM 194380]), but in the current case, it was identified to be a de novo mutation. We underscore DHS1 in the differential diagnosis of iron overload associated with non-transfused hemolytic anemia in children and young adults.

TREC/KREC Newborn Screening followed by Next-Generation Sequencing for Severe Combined Immunodeficiency in Japan.

PURPOSE: The aim of this study is to evaluate the usefulness of T cell receptor excision circle (TREC) and/or kappa-deleting recombination excision circle (KREC) measurements integrated with diagnostic next-generation sequencing (NGS) analysis using a severe combined immunodeficiency (SCID) newborn screening (NBS) program. METHODS: TREC and/or KREC values were measured in 137,484 newborns between April 2017 and December 2021 using EnLite TREC (n = 80,791) or TREC/KREC kits (n = 56,693). For newborns with positive screening results, diagnostic NGS analysis was performed with a 349-gene panel to detect genetic mutations associated with primary immunodeficiencies (PIDs). RESULTS: A total of 145 newborns (0.11%) had abnormal TREC and/or KREC values, and a genetic diagnosis was established in 2 patients with SCID (1 in 68,742 newborns) (IL2RG-SCID and reticular dysgenesis) and 10 with non-SCID PIDs with T and/or B cell deficiencies (1 in 13,748 newborns) using NGS analysis. Furthermore, TREC values of 2849 newborns were measured and confirmed the significant correlation between the results of both TREC and TREC/KREC kits (P < 0.001) and naïve T cell counts. CONCLUSIONS: We performed the first large-scale TREC and TREC/KREC NBS programs in Japan. Our NBS programs followed by the diagnostic NGS analysis for newborns with abnormal TREC and/or KREC values are useful for the early identification and rapid molecular evaluation of not only SCID but also different non-SCID PIDs.

Microsatellite instability-high is rare events in refractory pediatric solid tumors.

Microsatellite instability (MSI)-high status is associated with good responsiveness to immune checkpoint inhibitors. Although MSI-high status has been actively investigated in pediatric brain tumors, studies of other pediatric solid tumors are lacking. Among 334 consecutive pediatric patients with solid tumors, we retrospectively analyzed formalin-fixed paraffin-embedded tumor tissues of 36 of 74 patients (49%) who died of disease. We assessed the MSI status in these tissues using five multiplexed markers. The results revealed that none of the patients had an MSI-high status. These results indicate that MSI-high status is a rare event in pediatric patients with refractory/relapsed solid tumors.Supplemental data for this article is available online at https://doi.org/10.1080/08880018.2021.1998266.

[Disseminated Aspergillus siamensis infection following haploidentical bone marrow transplantation for chronic granulomatous disease].

An 18-year-old male patient who had been diagnosed with chronic granulomatous disease at 2 years old and suffering from repeated severe infections underwent human leukocyte antigen haploidentical bone marrow transplantation from his mother using reduced intensity conditioning. After engraftment, donor lymphocyte infusion was initiated to decrease donor chimerism on day 96. On day 120, acute graft-versus-host disease occurred; hence, steroid administration was initiated. On day 173, a generalized convulsion occurred; multiple abscesses were observed in the brain, lung, kidney, and prostate. Aspergillus siamensis of unknown pathogenic status was cultured in the abscess fluid from the brain, prostate, and kidney; accordingly, he was diagnosed with disseminated aspergillosis involving the brain, prostate, lungs, and kidney. Despite using a combination of various antifungal drugs, he died of multiple organ failure on day 239. Disseminated aspergillosis following the hematopoietic stem cell transplantation is a fatal complication. If infection symptoms are observed, the presence of any fungal antigens should be examined. Appropriate samples should be promptly collected, and adequate antifungal drugs should be administered based on the fungal species and drug sensitivity results.

Two cases of AMeD syndrome with isochromosome 1q treated with allogeneic stem cell transplantation.

AMeD syndrome is characterized by aplastic anemia, mental retardation, short stature, and microcephaly and is caused by digenic mutations in the aldehyde dehydrogenase 2 (ALDH2) and alcohol dehydrogenase 5 (ADH5) genes. We have successfully performed hematopoietic stem cell transplantation in two patients with AMeD syndrome and isochromosome 1q. AMeD syndrome with myelodysplastic syndrome or acute myeloblastic leukemia generally has a poor prognosis; however, early diagnosis may improve treatment response. Although the gain of 1q has been considered as a form of early clonal evolution in Fanconi anemia, it may be an equally important finding observed in AMeD syndrome.

Integrated proteogenomic analysis for inherited bone marrow failure syndrome.

Recent advances in in-depth data-independent acquisition proteomic analysis have enabled comprehensive quantitative analysis of >10,000 proteins. Herein, an integrated proteogenomic analysis for inherited bone marrow failure syndrome (IBMFS) was performed to reveal their biological features and to develop a proteomic-based diagnostic assay in the discovery cohort; dyskeratosis congenita (n = 12), Fanconi anemia (n = 11), Diamond-Blackfan anemia (DBA, n = 9), Shwachman-Diamond syndrome (SDS, n = 6), ADH5/ALDH2 deficiency (n = 4), and other IBMFS (n = 18). Unsupervised proteomic clustering identified eight independent clusters (C1-C8), with the ribosomal pathway specifically downregulated in C1 and C2, enriched for DBA and SDS, respectively. Six patients with SDS had significantly decreased SBDS protein expression, with two of these not diagnosed by DNA sequencing alone. Four patients with ADH5/ALDH2 deficiency showed significantly reduced ADH5 protein expression. To perform a large-scale rapid IBMFS screening, targeted proteomic analysis was performed on 417 samples from patients with IBMFS-related hematological disorders (n = 390) and healthy controls (n = 27). SBDS and ADH5 protein expressions were significantly reduced in SDS and ADH5/ALDH2 deficiency, respectively. The clinical application of this first integrated proteogenomic analysis would be useful for the diagnosis and screening of IBMFS, where appropriate clinical screening tests are lacking.

Risk factors of bloodstream infection after allogeneic hematopoietic cell transplantation in children/adolescent and young adults.

Allogeneic hematopoietic cell transplantation (HCT) is a crucial treatment for various diseases, including hematological malignancies, solid tumors, and genetic disorders. Despite its curative potential, HCT is associated with severe complications, notably infections, graft-versus-host disease, and organ damage. Infections, particularly bloodstream infections (BSIs), pose a significant threat in the initial weeks post-HCT, necessitating effective management strategies. This retrospective study aimed to clarify the incidence, pathogens, and risk factors associated with BSI within the first 30 days after allogeneic HCT in children/adolescents and young adults (AYAs). The study included 115 patients aged <31 years who underwent 121 allogeneic HCTs at the Department of Pediatrics, Nagoya University Hospital between January 1, 2018, and March 31, 2022. Data encompassed demographic characteristics, HCT details, and BSI information. Overall, 27 of 121 patients developed BSI with the cumulative incidence of 23.5% (95% confidence intervals [CI]: 17.0%-30.6%) at 30 days after HCT. The median onset time of BSI was 7 (range, 4-26 days) after HCT. Gram-positive bacteria accounted for 89% of pathogens isolated from blood cultures, with Streptococcus mitis/oralis being the most common. In multivariable analysis, tandem HCT (subdistribution hazard ratio [SHR]: 5.67, 95% CI: 2.74-11.7, p < 0.001) and peripherally inserted central catheters (SHR: 2.96, 95% CI: 1.34-6.55, p = 0.007) were identified as independent risk factors for BSI. In patients receiving tandem HCT, the pathogens isolated from blood cultures were all gram-positive bacteria, with Streptococcus mitis/oralis accounting for up to 67% of the isolated pathogens. Tandem HCT and PICCs were identified as independent risk factors for BSI after allogeneic HCT in children/AYAs. The pathogens were commonly gram-positive, and Streptococcus mitis/oralis is important in patients who received tandem HCT. These data can provide valuable information for future studies to consider effective interventions to reduce the risk of BSI in high-risk patients.

Successful treatment of DOCK8 deficiency by allogeneic hematopoietic cell transplantation from alternative donors.

Dedicator of cytokinesis 8 (DOCK8) deficiency is a rare autosomal recessive inborn error of immunity (IEI) characterized by eczematous dermatitis, elevated serum IgE, and recurrent infections, comprising a seemingly hyper-IgE syndrome (HIES). DOCK8 deficiency is only curable with allogeneic hematopoietic cell transplantation (HCT), but the outcome of HCT from alternative donors is not fully understood. Here, we describe the cases of two Japanese patients with DOCK8 deficiency who were successfully treated by allogeneic HCT from alternative donors. Patient 1 underwent cord blood transplantation at the age of 16 years, and Patient 2 underwent haploidentical peripheral blood stem cell transplantation with post-transplant cyclophosphamide at the age of 22 years. Each patient received a fludarabine-based conditioning regimen. Their clinical manifestations, including refractory molluscum contagiosum, promptly improved post-HCT. They achieved successful engraftment and immune reconstitution without serious complications. Alternative donor sources such as cord blood and haploidentical donors can be options for allogeneic HCT for DOCK8 deficiency.

Vedolizumab for children with intestinal graft-versus-host disease: a case report and literature review.

Acute graft-versus-host disease (aGVHD) is a challenging complication of allogeneic hematopoietic stem cell transplantation, and alternative therapies for patients showing inadequate response to steroids are limited. Vedolizumab, an anti-α4ß7 integrin antibody widely used for treating inflammatory bowel diseases, has recently been studied in adult patients with steroid-refractory intestinal aGVHD. However, few studies have examined its safety and effectiveness in pediatric patients with intestinal aGVHD. We report the case of a male patient with intestinal late-onset aGVHD treated with vedolizumab. He underwent allogeneic cord blood transplantation for warts, hypogammaglobulinemia, infections, and myelokathexis (WHIM) syndrome and developed intestinal late-onset aGVHD 31 months after transplantation. The patient was refractory to steroids; however, vedolizumab was initiated 43 months after transplantation (at the age of 7 years) and the symptoms of intestinal aGVHD were alleviated. Additionally, favorable endoscopic findings were observed, such as reduction of erosion and regenerative epithelial growth. We also evaluated the efficacy of vedolizumab in 10 patients with intestinal aGVHD (9 from the literature review and the present case). Six patients (60%) showed an objective response to vedolizumab. No serious adverse events were observed in any patients. Vedolizumab is a potential treatment option for steroid-refractory intestinal aGVHD in pediatric patients.

Two Cases of Juvenile Myelomonocytic Leukemia and Myelin Oligodendrocyte Glycoprotein Antibody-Associated Disease.

BACKGROUND: Myelin oligodendrocyte glycoprotein (MOG) antibody-associated disease (MOGAD) is an autoimmune demyelinating disorder that often manifests after infections or vaccinations. We report two patients who developed MOGAD out of eight patients with juvenile myelomonocytic leukemia (JMML) that has never been reported. METHODS: We investigated two patients with JMML who developed MOGAD among 127 patients with leukemia from 2012 to 2021. RESULTS: Patient 1 was treated for JMML and developed fever and impaired consciousness at two years and one month of age. Magnetic resonance imaging revealed high-intensity lesions in the left frontal and left occipital white matter. The serum anti-MOG antibody test was positive, while the test was negative in the stored serum 45 days before the onset of encephalopathy. He had relapse of MOGAD after steroid therapy and plasmapheresis. Patient 2, who was treated for JMML, became apathetic and mute at three years and seven months of age. Magnetic resonance imaging revealed left frontoparietal subcortical high-intensity lesions. Anti-MOG antibody at the onset of encephalopathy was positive, while it was negative in stored serum 57 days before and 47 days after the onset. CONCLUSION: We treated two patients who developed MOGAD out of eight patients with JMML and none with MOGAD out of 119 patients with acute lymphocytic leukemia, acute myelocytic leukemia, or chronic myelocytic leukemia. The activated autoimmune process via the RAS pathway abnormality may have led to the formation of the anti-MOG antibody and the onset of MOGAD. MOGAD can occur in children with JMML, and abnormalities of the RAS pathway possibly contribute to its onset.