[Hyper-IgM syndrome with early liver involvement]. / Síndrome de hiper-IgM con afectación hepática temprana.

INTRODUCTION: Hyper-IgM syndrome is an innate error of immunity in which there is a defect in change of isotype of immunoglobulins, with decreased values of IgG, IgA, and IgE, but normal or increased level of IgM. This predisposes to infectious processes at the respiratory and gastrointestinal levels, as well as autoimmune diseases and neoplasm. CASE REPORT: A 5 year 7-month-old boy with a history of 2 pneumonias, one of them severe, and chronic diarrhea since he was 2 years old. Persistent moderate neutropenia decreased IgG and elevated IgM. Cytometry flow confirmed absence of CD40L. Clinical evolution with early hepatic involvement. DISCUSSION: Hyper-IgM syndrome predisposes to liver damage, so a complete evaluation is required as well as early diagnosis. Active anti-infective treatment and control of the inflammatory response are key to the treatment of liver damage.

INTRODUCCIÓN: El síndrome de hiper-IgM es un error innato de la inmunidad, caracterizado por un defecto en el cambio de isotipo de inmunoglobulina, con valores disminuidos de IgG, IgA e IgE, y concentraciones normales o elevadas de IgM. Predispone a procesos infecciosos en el sistema respiratorio y aparato gastrointestinal, además de enfermedades autoinmunes y neoplasias. REPORTE DE CASO: Paciente pediátrico de género masculino, de 5 años y 7 meses de edad, con antecedente de dos cuadros de neumonía (uno de estos grave) y diarrea crónica desde los 2 años. Neutropenia moderada persistente, disminución de la concentración de IgG y elevación de IgM. La citometría de flujo confirmó la ausencia de CD40L. Durante la evolución clínica tuvo afectación hepática temprana. CONCLUSIÓn: El síndrome de hiper-IgM predispone a daño hepático, por lo que se requiere la evaluación completa y el diagnóstico oportuno. El tratamiento antiinfeccioso activo y el control de la respuesta inflamatoria son factores decisivos para establecer el tratamiento del daño hepático.

Type 2 hyper-IgM syndrome with a rare variant of AICDA gene mutation in a young woman.

We report the case of a woman in her early 20s with a history of recurrent infection, atopic dermatitis, filariasis and bilateral purulent ear discharge since childhood with tonsillar enlargement on examination. She was started on supportive care and evaluated for primary immunodeficiency disease. Blood investigations revealed increased IgM levels with reduced IgG, IgA and IgE levels. Radiological imaging of the chest revealed bilateral bronchiectasis. Otoscopic examination showed features suggestive of chronic suppurative otitis media. Next-generation sequencing identified homozygous single base pair deletion in exon 2 of the activation-induced cytidine deaminase gene. Thus, a diagnosis of hyper-IgM syndrome type 2 was confirmed. The patient was started on monthly intravenous immunoglobulin replacement therapy and is currently symptomatically better, and she remains under regular follow-up.

Respiratory infections in X-linked hyper-IgM syndrome with CD40LG mutation: a case series of seven children in China.

BACKGROUND: X-linked hyper-immunoglobulin M (XHIGM), a primary immunodeficiency syndrome caused by mutations in the CD40 ligand gene(CD40LG), presents with recurrent respiratory infections in pediatric patients. We aimed to evaluate the spectrum of clinical features and respiratory pathogens in pediatric patients with XHIGM in China. METHODS: We retrospectively reviewed seven pediatric patients who were diagnosed with XHIGM and received follow-up treatment at the Guangzhou Women and Children's Medical Center between January 2010 and January 2021. We determined their clinical characteristics, causative pathogens, and prognosis by performing peripheral immunological and genetic tests. RESULTS: There were seven boys with age ranging from 4-20 months (median age, 13 months). Four of the seven respiratory infections were caused by Talaromyces marneffei(T. marneffei). Two patients had viral infections caused by cytomegalovirus (CMV) and human adenovirus respectively. One patient had a mixed infection caused by Pneumocystis carinii and CMV. Except for one child who died of respiratory failure, one patient received hematopoietic stem cell transplantation (HSCT) and recovered well, the other five patients survived with regular infusions of intravenous immunoglobulin (IVIg) during the follow-up period. Six patients had reduced antibody levels, especially IgG, IgA, and IgE levels. Increased serum IgM levels were detected in four cases, and three cases presented normal IgM levels at onset. All children were diagnosed with XHIGM with CD40LG variation. Three novel mutations were identified in the present study. CONCLUSIONS: Our study suggests that respiratory infections usually begin within 2 years old, fungi and viruses are important pathogens causing respiratory infections in children with XHIGM. In endemic areas, T. marneffei is the common pathogen of respiratory tract infection in children with the disease.

X-linked hyper IgM syndrome with severe eosinophilia: a case report and review of the literature.

BACKGROUND: Hyper IgM syndromes (HIGMS) are a group of rare primary immunodeficiency disorders. There are limited reports about HIGMS combined with severe eosinophilia. CASE PRESENTATION: In this report, we described a 2-year-old boy with chronic cough and symptoms of hypoxia. Lung computed tomography (CT) scan showed that diffuse ground-glass changes and eosinophils in peripheral blood increased significantly. Subsequent tests revealed a notable decrease in serum IgG and IgA. The lymphocyte subgroup classification was basically normal. Pneumocystis jirovecii were detected from the bronchoalveolar lavage fluid (BALF) of the patient by metagenomic next-generation sequencing (mNGS). After treatments of caspofungin combined with sulfamethoxazole, intravenous immunoglobulin (IVIG) replacement and anti-inflammatory steroid, the clinical symptoms and pulmonary imaging noticeably improved. The absolute eosinophil count (AEC) also returned to normal range. X-linked hyper IgM syndrome was confirmed by gene test. Two months after the diagnosis, the patient underwent allogeneic stem cell transplantation (HSCT) and has recovered well. CONCLUSIONS: Children with HIGMS are prone to opportunistic infections such as Pneumocystis jirovecii pneumonia (PJP). Diffuse interstitial lung disease and hypoglobulinemia in a young child predict the diagnosis of a primary immunodeficiency (PID). mNGS has obvious advantages for obtaining etiological diagnosis of children with PIDs. Severe eosinophilia is rarely reported in this kind of PIDs. Considering literature review and the corresponding reaction to steroid, we proposed that eosinophilia in HIGMS might be related to infections. Steroid therapy can quickly relieve eosinophilia but is easy to rebound if the reduction is too fast. Once the diagnosis of HIGMS is confirmed, the earlier the HSCT, the better the prognosis.

Understanding neutropenia secondary to intrinsic or iatrogenic immune dysregulation.

As a key member of the innate and adaptive immune response, neutrophils provide insights into the hematopoietic and inflammatory manifestations of inborn errors of immunity (IEI) and the consequences of immunotherapy. The facile recognition of IEI presenting with neutropenia provides an avenue for hematologists to facilitate early diagnosis and expedite biologically rationale care. Moreover, enhancing the understanding of the molecular mechanisms driving neutropenia in IEI-decreased bone marrow reserves, diminished egress from the bone marrow, and decreased survival-offers an opportunity to further dissect the pathophysiology driving neutropenia secondary to iatrogenic immune dysregulation, eg, immune checkpoint inhibitors and chimeric antigen receptor T-cell therapy.

Bell's palsy in a pediatric patient with hyper IgM syndrome and severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2).

Bell's palsy is an acute facial paralysis with known association to viral infections. We describe a medically complex 6-year-old male with hyper IgM syndrome who presented with unilateral facial droop and positive SARS-CoV-2 RT-PCR. This is the first reported pediatric case of Bell's palsy in the setting of SARS-CoV-2 infection.

Diagnosis of Hyper IgM syndrome in a Previously Healthy Adolescent Boy Presented with Cutaneous and Cerebral Cryptococcosis.

X-linked hyper IgM (X-HIGM) syndrome is a combined immunodeficiency disease caused by mutations in the CD40LG gene, leading to a defect in immunoglobulin (Ig) class switching recombination and effector T-cell responses. X-HIGM patients usually present in early life with pyogenic bacterial and opportunistic infections. Herein, we report a previously healthy 13-year-old Thai boy who first presented with cutaneous and meningoencephalitis cryptococcosis. Whole-exome sequencing revealed that he was hemizygous for a missense c.514T>C (p.Tyr172His) in CD40LG, confirming a diagnosis of X-HIGM. This report demonstrates that X-HIGM could have an age of onset in teens and systemic cryptococcosis could be its presenting symptoms.

Case Report: Hyper IgM Syndrome Identified by Whole Genome Sequencing in a Young Syrian Man Presenting With Atypical, Severe and Recurrent Mucosal Leishmaniasis.

A previously healthy 19-year-old Syrian man presented with atypical and severe mucosal leishmaniasis caused by Leishmania tropica. During a 2-year period, he had three severe relapses despite various treatment strategies, including liposomal amphotericin B and Miltefosine. Because of the unusual clinical presentation, potential underlying immunodeficiency was investigated. Normal T and NK cell counts were found. The B cell count was slightly elevated at 0.7 × 109 cells/L (0.09 × 109 to 0.57 × 109 cells/L), but the proportions of memory and isotype switched memory B cells were severely diminished IgG levels were low, at 309 mg/dL (610-1490 mg/dL). The initial IgM and IgA levels were within normal range, but the IgA levels decreased to 57 mg/dL (70-430 mg/dL) during follow up. Common variable immunodeficiency (CVID) was initially suspected, because the immunological results of low IgG and IgA, low switched memory B cells, no profound T cell deficiency found and absence of secondary cause of hypogammaglobulinemia were compatible with this diagnosis (ESID 2019). However, the highly unusual and severe clinical presentation of L. tropica is not suggestive of B-cell deficiency or CVID. Eventually a pathogenic nonsense variant in the CD40 ligand gene [p.(Arg11∗)] was identified by whole genome sequencing, thus enabling the diagnosis of X-linked hyper IgM syndrome. This case illustrates and supports the potential for the use of whole genome sequencing in accurate diagnosis of primary immunodeficiencies.

Respiratory Complications in Patients with Hyper IgM Syndrome.

PURPOSE: Hyper Immunoglobulin M (HIgM) syndrome is a heterogeneous group of primary immunodeficiency disorders, characterized by recurrent infections and associated with decreased serum IgG and IgA, but normal or increased IgM. The aim of the present study was to evaluate respiratory manifestations in patients with HIgM syndrome. METHODS: A total number of 62 patients, including 46 males and 16 females were included in the present study. To investigate the respiratory complications among HIgM patients, we evaluated the clinical hospital records, immunologic and molecular diagnostic assays, pulmonary function tests (PFT), and high-resolution computed tomography (HRCT) scans. RESULTS: Pneumonia was the most common respiratory manifestation (n = 35, 56.4%), followed by otitis media (45.1%), sinusitis (33.8%), and bronchiectasis (14.5%). 52.1% of the patients had abnormal PFT results, with a predominant restrictive pattern of changes. HRCT scans demonstrated abnormal findings in 85.7% of patients with found mutations. Ten cases had hilar lymphadenopathy and para-hilar infiltrates in their HRCT findings. Genetic diagnosis was confirmed in 29 HIgM patients (72.4% CD40 ligand (CD40L) and 24.1% activation-induced cytidine deaminase (AICDA/AID) deficiencies). Majority of patients with CD40L (71.4%) and AID (57.1%) deficiencies had missense mutations. Pneumonia and abnormal high-resolution computed tomography (HRCT) findings were more frequent among patients with CD40L mutation. Respiratory failure constituted the major cause of mortality (37.5%) with majority of cases occurring in CD40L-deficient patients (50%). CONCLUSIONS: Respiratory complications are common in patients with HIgM syndrome. A proper awareness of respiratory manifestations in patients with HIgM may result in improved management, reduced morbidity and mortality, and an improvement in the quality of life of the patients.

The hyper IgM syndromes: Epidemiology, pathogenesis, clinical manifestations, diagnosis and management.

Hyper Immunoglobulin M syndrome (HIGM) is a rare primary immunodeficiency disorder characterized by low or absent levels of serum IgG, IgA, IgE and normal or increased levels of serum IgM. Various X-linked and autosomal recessive/dominant mutations have been reported as the underlying cause of the disease. Based on the underlying genetic defect, the affected patients present a variety of clinical manifestations including pulmonary and gastrointestinal complications, autoimmune disorders, hematologic abnormalities, lymphoproliferation and malignancies which could be controlled by multiple relevant therapeutic approaches. Herein, the epidemiology, pathogenesis, clinical manifestations, diagnosis, management, prognosis and treatment in patients with HIGM syndrome have been reviewed.

Scalp Lesions in a Pediatric Patient with Hyper IgM Syndrome: Clinical and Histologic Mimicry of Cryptococcus neoformans Infection.

We report a case of cutaneous cryptococcosis due to Cryptococcus neoformans in a pediatric patient with hyper IgM syndrome with scalp lesions that resembled tinea capitis on gross examination and mimicked juvenile xanthogranuloma on histologic examination. This case highlights the importance of considering cutaneous cryptococcosis in patients with hyper IgM syndrome.

A Severe Anaphylactic Reaction Associated with IgM-Class Anti-Human IgG Antibodies in a Hyper-IgM Syndrome Type 2 Patient.

PURPOSE: A 42-year-old man with hyper-IgM syndrome type 2 caused by activation-induced cytidine deaminase (AID) deficiency developed a severe anaphylactic reaction to intravenous immunoglobulin. The purpose of this study was to clarify the cause of the anaphylactic reaction of the patient. METHODS: We measured IgM-class anti-human IgG and anti-human IgA antibodies in his serum by sandwich enzyme-linked immunosorbent assay (ELISA). RESULTS: The sandwich ELISA assay revealed that serum from the patient, but not the controls, reacted to three different IgG products and purified human IgA. This indicated that the patient had IgM-class anti-human IgG and IgA antibodies in his serum, which associated with the anaphylactic reactions after the administration of IgG products. The anti-IgG antibody was likely to be the main cause of the reactions because an IgA-depleted IgG product also induced a severe reaction in this case and showed high absorbance in the ELISA system, similar to other IgG products containing more IgA. CONCLUSIONS: This is the first report of IgM-class anti-human IgG associated with an anaphylactic reaction to an IgG infusion. The anaphylactic reactions were very severe in this case, probably because IgM-class antibodies are potent activators of the complement pathway.

Ataxia-telangiectasia: Immunodeficiency and survival.

Ataxia-telangiectasia (AT) is a neurodegenerative disorder characterized by ataxia, telangiectasia, and immunodeficiency. An increased risk of malignancies and respiratory diseases dramatically reduce life expectancy. To better counsel families, develop individual follow-up programs, and select patients for therapeutic trials, more knowledge is needed on factors influencing survival. This retrospective cohort study of 61 AT patients shows that classical AT patients had a shorter survival than variant patients (HR 5.9, 95%CI 2.0-17.7), especially once a malignancy was diagnosed (HR 2.5, 95%CI 1.1-5.5, compared to classical AT patients without malignancy). Patients with the hyper IgM phenotype with hypogammaglobulinemia (AT-HIGM) and patients with an IgG2 deficiency showed decreased survival compared to patients with normal IgG (HR 9.2, 95%CI 3.2-26.5) and patients with normal IgG2 levels (HR 7.8, 95%CI 1.7-36.2), respectively. If high risk treatment trials will become available for AT, those patients with factors indicating the poorest prognosis might be considered for inclusion first.

Fatal Scopulariopsis brumptii in a Pediatric Immunocompromised Host.

Scopulariopsis species cause a broad range of disease, from superficial skin infections to often fatal disseminated disease in the immunocompromised that is refractory to standard antifungal treatment. This report describes the first case of fatal disseminated Scopulariopsis brumptii in a pediatric patient with hyper-IgM syndrome status post bone marrow transplant.