Rubella Virus-Associated Cutaneous Granulomatous Disease: a Unique Complication in Immune-Deficient Patients, Not Limited to DNA Repair Disorders

Newborn screening for SCID and severe T lymphocytopenia in Europe

Initiation of newborn screening (NBS) programs in Europe dates back to the 1960s. One of the most recent expansions of NBS programs was the addition of severe combined immunodeficiency (SCID) based on detection of T-cell receptor excision circles (TRECs). In this review, we present an overview of the current situation in Europe. To avoid a biased overview based on only published results, a 37-item survey on TREC-based NBS was sent to representatives of 46 European countries. With a response rate of 83%, we collected data of 38 countries. Seventeen of the 38 European countries that have completed the survey have nationally or regionally implemented TREC-based NBS. The survey results emphasize similarities and differences as well as common practices and challenges in TREC-based NBS. Because TRECs are a general surrogate marker for severe T lymphocytopenia, conditions other than SCID are also identified. Therefore, the initial definition of the target disease as "SCID" might need to be reconsidered and extended to "SCID and severe T lymphocytopenia." Even though complete harmonization of TREC-based NBS programs across Europe will remain challenging, collaboration and close partnerships will help in the move toward universal TREC-based screening for all newborns, resulting in more infants with SCID and severe T lymphocytopenia being detected each year.

Rubella virus vaccine-induced granulomas: a case in children with ataxia-telangiectasia

Ataxia telangiectasia (AT) is a rare autosomal recessive primary immunodeficiency disorder (PID) resulting from a mutation in the ATM gene involved in DNA repair. We describe the case of a young girl with cutaneous granulomas that developed after childhood vaccinations. Immunohistochemistry revealed granulomas induced by the rubella virus vaccine. This finding raises the question of the safety of live rubella vaccine strains in immunocompromised children.

Human DNA-dependent protein kinase catalytic subunit deficiency: A comprehensive review and update

BACKGROUND

DNA-dependent protein kinase catalytic subunit (DNA-PKcs) has an essential role in the non-homologous end-joining pathway that repairs DNA double-strand breaks in V(D)J recombination involved in the expression of T- and B-cell receptors. Whereas homozygous mutations in Prkdc define the Scid mouse, a model that has been widely used in biology, human mutations in PRKDC are extremely rare and the disease spectrum has not been described so far.

OBJECTIVES

To provide an update on the genetics, clinical spectrum, immunological profile, and therapy of DNA-PKcs deficiency in human.

METHODS

The clinical, biological, and treatment data from the 6 cases published to date and from 1 new patient were obtained and analyzed. Rubella PCR was performed on available granuloma material.

RESULTS

We report on 7 patients; 6 patients displayed the autosomal recessive p.L3062R mutation in PRKDC-encoding DNA-PKcs. Atypical severe combined immunodeficiency with inflammatory lesions, granulomas, and autoimmunity was the predominant clinical manifestation (n = 5 of 7). Rubella viral strain was detected in the granuloma of 1 patient over the 2 tested. T-cell counts, including naive CD4+CD45RA+ T cells and T-cell function were low at diagnosis for 6 patients. For most patients with available values, naive CD4+CD45RA+ T cells decreased over time (n = 5 of 6). Hematopoietic stem cell transplantation was performed in 5 patients, of whom 4 are still alive without transplant-related morbidity. Sustained T- and B-cell reconstitution was observed, respectively, for 4 and 3 patients, after a median follow-up of 8 years (range 3-16 years).

CONCLUSIONS

DNA-PKcs deficiency mainly manifests as an inflammatory disease with granuloma and autoimmune features, along with severe infections.

Cancer Trends in Inborn Errors of Immunity: A Systematic Review and Meta-Analysis

BACKGROUND

Patients with inborn errors of immunity (IEI) are susceptible to developing cancer due to defects in the immune system. The prevalence of cancer is higher in IEI patients compared to the immunocompetent population and cancers are considered as an important and common cause of death in IEI patients.

OBJECTIVES

To systematically review demographic, genetic and cancer-related data of IEI patients with a history of malignancy. Moreover, we performed a meta-analysis aiming to determine the frequency of cancer in patients with different types of IEI.

METHODS

We conducted electronic searches on Embase, Web of Science, PubMed, and Scopus (until September 2023) introducing terms related to IEI and cancer. Studies with human subjects with confirmed IEI who had developed at least one malignancy during their lifetime were included.

RESULTS

A total number of 4607 IEI patients with a cancer history were included in the present study. Common variable immunodeficiency (CVID) had the highest number of reported cases (1284 cases), mainly due to a higher relative proportion of patients with predominantly antibody deficiencies (PAD) and their increased life expectancy contributing to the higher detection and reporting of cancers among these patients. The most common malignancy was hematologic/blood cancers (3026 cases, mainly diffuse large B cell lymphoma). A total number of 1173 cases (55.6%) succumbed to cancer, with the highest rate of bone marrow failure (64.9%). Among the patients with monogenic defects in IEI-associated genes, the majority of cases had ATM deficiency (926 cases), but the highest cancer frequency rate belonged to NBS1 deficiency (50.5%). 1928 cases out of total 4607 eligible cases had detailed data to allow further statistical analysis that revealed BRCA2 deficiency had the earliest cancer development (~ 38 months), lowest cure frequency, and highest fatality rate (85%), while ATM deficiency had the lowest cure frequency and highest fatality rate (72%) among total cases reviewed with exclusion of Fanconi anemia.

CONCLUSION

The overall reported cancer frequency in the cases reviewed with and without exclusion of Fanconi anemia was 11.1% (95% confidence interval: 9.8-12.5%) and 12.0% (95% confidence interval: 10.6-13.5%), respectively. Our study revealed that the incidence of cancer is significantly dependent on the molecular and pathway defects in IEI patients, and individualized early screening and appropriate treatment, might improve the prognosis of these patients.

Neutralization of Rubella Vaccine Virus and Immunodeficiency-Related Vaccine-Derived Rubella Viruses by Intravenous Immunoglobulins

The association between granulomas and vaccine-derived rubella virus (VDRV) in people with primary immunodeficiencies has raised concerns about the ability of immunoglobulin preparations to neutralize VDRVs. We investigated the capacity of immunoglobulin to neutralize rubella vaccine virus and 4 VDRV strains. As expected, the rubella vaccine virus itself was potently neutralized by immunoglobulin preparations, but the VDRV isolates from patients after intrahost evolution, 2-6 times less so. Diagnosis of immune deficiencies before possible live-virus vaccination is thus of critical importance, while immunoglobulin replacement therapy can be expected to provide protection from rubella virus infection.

Monogenic Inborn Errors of Immunity with impaired IgG response to polysaccharide antigens but normal IgG levels and normal IgG response to protein antigens

In patients with severe and recurrent infections, minimal diagnostic workup to test for Inborn Errors of Immunity (IEI) includes a full blood count, IgG, IgA and IgM. Vaccine antibodies against tetanus toxoid are also frequently measured, whereas testing for anti-polysaccharide IgG antibodies and IgG subclasses is not routinely performed by primary care physicians. This basic approach may cause a significant delay in diagnosing monogenic IEI that can present with an impaired IgG response to polysaccharide antigens with or without IgG subclass deficiency at an early stage. Our article reviews genetically defined IEI, that may initially present with an impaired IgG response to polysaccharide antigens, but normal or only slightly decreased IgG levels and normal responses to protein or conjugate vaccine antigens. We summarize clinical, genetic, and immunological findings characteristic for these IEI. This review may help clinicians to identify patients that require extended immunologic and genetic evaluations despite unremarkable basic immunologic findings. We recommend the inclusion of anti-polysaccharide IgG antibodies as part of the initial routine work-up for possible IEI.

Rubella virus chronic inflammatory disease and other unusual viral phenotypes in inborn errors of immunity

Infectious susceptibility is a component of many inborn errors of immunity. Nevertheless, antibiotic use is often used as a surrogate in history taking for infectious susceptibility, thereby disadvantaging patients who present with viral infections as their phenotype. Further complicating clinical evaluations are unusual manifestations of viral infections which may be less familiar that the typical respiratory viral infections. This review covers several unusual viral phenotypes arising in patients with inborn errors of immunity and other settings of immune compromise. In some cases, chronic infections lead to oncogenesis or tumor-like growths and the conditions and mechanisms of viral-induced oncogenesis will be described. This review covers enterovirus, rubella, measles, papillomavirus, and parvovirus B19. It does not cover EBV and hemophagocytic lymphohistiocytosis nor lymphomagenesis related to EBV. EBV susceptibility has been recently reviewed. Our goal is to increase awareness of the unusual manifestations of viral infections in patients with IEI and to describe treatment modalities utilized in this setting. Coincidentally, each of the discussed viral infections can have a cutaneous component and figures will serve as a reminder of the physical features of these viruses. Given the high morbidity and mortality, early recognition can only improve outcomes.

Cutaneous granulomas associated with rubella virus: A clinical review

Since the initial identification of vaccine-derived rubella virus (RuV) in the cutaneous granulomas of pediatric patients with inborn errors of immunity in 2014, more than 80 cases of RuV granulomas have been reported implicating both vaccine-derived and wild type RuV. Previously thought to arise exclusively in patients with significant immunocompromise, the identification of RuV granulomas in clinically immunocompetent patients adds nuance to our understanding of the interplay between host environment, immune dysregulation, and RuV granuloma formation. This review summarizes the literature on RuV granulomas including clinical and histopathologic features, proposed pathomechanisms supporting granuloma development, and potential therapeutic options. There is no standardized algorithm to guide the workup and diagnosis of suspected RuV granulomas. We highlight the importance of contributing RuV granuloma cases to ongoing Centers for Disease Control and Prevention surveillance efforts to monitor wild type and vaccine-derived RuV transmission. Studies advancing our understanding of RuV granulomas may provide insights into the role of viral infectious agents in granulomatous disease pathogenesis and guide the development of improved therapeutic options.

Autoimmunity and immunodeficiency associated with monoallelic LIG4 mutations via haploinsufficiency

BACKGROUND

Biallelic mutations in LIG4 encoding DNA-ligase 4 cause a rare immunodeficiency syndrome manifesting as infant-onset life-threatening and/or opportunistic infections, skeletal malformations, radiosensitivity and neoplasia. LIG4 is pivotal during DNA repair and during V(D)J recombination as it performs the final DNA-break sealing step.

OBJECTIVES

This study explored whether monoallelic LIG4 missense mutations may underlie immunodeficiency and autoimmunity with autosomal dominant inheritance.

METHODS

Extensive flow-cytometric immune-phenotyping was performed. Rare variants of immune system genes were analyzed by whole exome sequencing. DNA repair functionality and T-cell-intrinsic DNA damage tolerance was tested with an ensemble of in vitro and in silico tools. Antigen-receptor diversity and autoimmune features were characterized by high-throughput sequencing and autoantibody arrays. Reconstitution of wild-type versus mutant LIG4 were performed in LIG4 knockout Jurkat T cells, and DNA damage tolerance was subsequently assessed.

RESULTS

A novel heterozygous LIG4 loss-of-function mutation (p.R580Q), associated with a dominantly inherited familial immune-dysregulation consisting of autoimmune cytopenias, and in the index patient with lymphoproliferation, agammaglobulinemia, and adaptive immune cell infiltration into nonlymphoid organs. Immunophenotyping revealed reduced naive CD4+ T cells and low TCR-Vα7.2+ T cells, while T-/B-cell receptor repertoires showed only mild alterations. Cohort screening identified 2 other nonrelated patients with the monoallelic LIG4 mutation p.A842D recapitulating clinical and immune-phenotypic dysregulations observed in the index family and displaying T-cell-intrinsic DNA damage intolerance. Reconstitution experiments and molecular dynamics simulations categorize both missense mutations as loss-of-function and haploinsufficient.

CONCLUSIONS

This study provides evidence that certain monoallelic LIG4 mutations may cause human immune dysregulation via haploinsufficiency.

Ataxia-telangiectasia clinical trial landscape and the obstacles to overcome

INTRODUCTION

Ataxia telangiectasia (A-T) is a life-limiting autosomal recessive disease characterized by cerebellar degeneration, ocular telangiectasias, and sinopulmonary disease. Since there is no cure for A-T, the standard of care is primarily supportive.

AREAS COVERED

We review clinical trials available in PubMed from 1990 to 2023 focused on lessening A-T disease burden. These approaches include genetic interventions, such as antisense oligonucleotides, designed to ameliorate disease progression in patients with select mutations. These approaches also include pharmacologic treatments that target oxidative stress, inflammation, and mitochondrial exhaustion, to attenuate neurological progression in A-T. Finally, we discuss the use of biological immunotherapies for the treatment of malignancies and granulomatous disease, along with other supportive therapies being used for the treatment of pulmonary disease and metabolic syndrome.

EXPERT OPINION

Barriers to successful genetic and pharmacologic interventions in A-T include the need for personalized treatment approaches based on patient-specific ATM mutations and phenotypes, lack of an animal model for the neurologic phenotype, and extreme rarity of disease making large-scale randomized trials difficult to perform. Ongoing efforts are needed to diagnose patients earlier, discover more effective therapies, and include more individuals in clinical trials, with the goal to lessen disease burden and to find a cure for patients with A-T.

Efficient screening strategies for severe combined immunodeficiencies in newborns

INTRODUCTION

Severe combined immunodeficiency (SCID) is one of the most severe forms of inborn errors of immunity (IEI), affecting both cellular and humoral immunity. Without curative treatment such as hematopoietic stem cell transplantation or gene therapy, affected infants die within the first year of life. Due to the severity of the disease, asymptomatic status early in life, and improved survival in the absence of pretransplant infections, SCID was considered a suitable candidate for newborn screening (NBS).

AREAS COVERED

Many countries have introduced SCID screening based on T-cell receptor excision circle (TREC) detection in their NBS programs. Screening an entire population is a radical departure from previous paradigms in the field of immunology. Efficient screening strategies are cost-efficient and balance high sensitivity while preventing high numbers of referrals. NBS for SCID is accompanied by (actionable) secondary findings, but many NBS programs have optimized their screening strategy by adjusting algorithms or including second-tier tests. Harmonization of screening terminology is of great importance for international shared learning.

EXPERT OPINION

The expansion of NBS is driven by the development of new test modalities and treatment options. In the near future, other techniques such as next-generation sequencing will pave the way for NBS of other IEI. Exciting times await for population-based screening programs.

Case report: Rubella virus-induced cutaneous granulomas in a girl with atypical SCID caused by DCLRE1C gene mutations

Here, we report a case of rubella virus-induced granulomatous dermatitis in a young girl with immunodeficiency caused by DCLRE1C gene mutations. The patient was a 6-year-old girl who presented with multiple erythematous plaques on the face and limbs. Biopsies of the lesions revealed tuberculoid necrotizing granulomas. No pathogens could be identified on extensive special stains, tissue cultures, or PCR-based microbiology assays. Metagenomic next-generation sequencing analysis revealed the rubella virus. Underlying atypical severe combined immunodeficiency was recognized based on the patient’s history of repetitive infections since birth, low T-cell, B-cell, and NK cell counts, and abnormal immunoglobulins and complements. Whole-exome sequencing revealed the genetic abnormality of the atypical severe combined immunodeficiency (SCID), and compound heterozygous mutations of the DCLRE1C gene were detected. This report highlights the diagnostic values of metagenomic next-generation sequencing in identifying rare pathogens causing cutaneous granulomas in patients with atypical SCID.

Infections in DNA Repair Defects

DNA repair defects are heterogenous conditions characterized by a wide spectrum of clinical phenotypes. The common presentations of DNA repair defects include increased risk of cancer, accelerated aging, and defects in the development of various organs and systems. The immune system can be affected in a subset of these disorders leading to susceptibility to infections and autoimmunity. Infections in DNA repair defects may occur due to primary defects in T, B, or NK cells and other factors such as anatomic defects, neurologic disorders, or during chemotherapy. Consequently, the characteristics of the infections may vary from mild upper respiratory tract infections to severe, opportunistic, and even fatal infections with bacteria, viruses, or fungi. Here, infections in 15 rare and sporadic DNA repair defects that are associated with immunodeficiencies are discussed. Because of the rarity of some of these conditions, limited information is available regarding infectious complications.

Granulomatous inflammation in inborn errors of immunity

Granulomas have been defined as inflammatory infiltrates formed by recruitment of macrophages and T cells. The three-dimensional spherical structure typically consists of a central core of tissue resident macrophages which may merge into multinucleated giant cells surrounded by T cells at the periphery. Granulomas may be triggered by infectious and non-infectious antigens. Cutaneous and visceral granulomas are common in inborn errors of immunity (IEI), particularly among patients with chronic granulomatous disease (CGD), combined immunodeficiency (CID), and common variable immunodeficiency (CVID). The estimated prevalence of granulomas in IEI ranges from 1%-4%. Infectious agents causing granulomas such Mycobacteria and Coccidioides presenting atypically may be 'sentinel' presentations for possible underlying immunodeficiency. Deep sequencing of granulomas in IEI has revealed non-classical antigens such as wild-type and RA27/3 vaccine-strain Rubella virus. Granulomas in IEI are associated with significant morbidity and mortality. The heterogeneity of granuloma presentation in IEI presents challenges for mechanistic approaches to treatment. In this review, we discuss the main infectious triggers for granulomas in IEI and the major forms of IEI presenting with 'idiopathic' non-infectious granulomas. We also discuss models to study granulomatous inflammation and the impact of deep-sequencing technology while searching for infectious triggers of granulomatous inflammation. We summarize the overarching goals of management and highlight the therapeutic options reported for specific granuloma presentations in IEI.

Metagenomic sequencing of the bronchoalveolar lavage extracellular virome and cellular transcriptome of sarcoidosis patients does not detect rubella virus

BACKGROUND

  Sarcoidosis is a multisystem granulomatous inflammatory disease of unclear etiology that involves the lung, skin and other organs, with an unknown antigenic trigger. Recently, evidence has been found in both immune deficient and immune competent patients for rubella virus in cutaneous granulomas. These granulomatous lesions share overlapping features with cutaneous sarcoidosis, raising the question of rubella virus in sarcoidosis.

OBJECTIVE

To investigate the presence of rubella virus in sarcoidosis lung samples.

METHODS

We employed metagenomic sequencing to interrogate extracellular virome preparations and cellular transcriptomes from bronchoalveolar lavage (BAL) of 209 sarcoidosis patients for rubella virus sequences.

RESULTS

We found no evidence for rubella virus genomes in acellular fluid or rubella virus gene expression in BAL cells of sarcoidosis patients.

CONCLUSIONS

These findings argue against rubella virus infection or persistence within the lung at time of sampling as a sarcoidosis trigger.

Case report: Persistent shedding of a live vaccine-derived rubella virus in a young man with severe combined immunodeficiency and cutaneous granuloma

A young man with X-linked severe combined immunodeficiency developed a persistent vaccine-derived rubella virus (VDRV) infection, with the emergence of cutaneous granulomas more than fifteen years after receipt of two doses of measles-mumps-rubella (MMR) vaccine. Following nasopharyngeal swab (NP) collection, VDRV was detected by real-time polymerase chain reaction (RT-qPCR) and sequencing, and live, replication-competent VDRV was isolated in cell culture. To assess duration and intensity of viral shedding, sequential respiratory samples, one cerebrospinal fluid sample, and two urine samples were collected over 15 months, and VDRV RNA was detected in all samples by RT-qPCR. Live VDRV was cultured from nine of the eleven respiratory specimens and from one urine specimen. To our knowledge, this was the first reported instance of VDRV cultured from respiratory specimens or from urine. To assess potential transmission to close contacts, NP specimens and sera were collected from all household contacts, all of whom were immunocompetent and previously vaccinated with MMR. VDRV RNA was not detected in any NP swabs from the contacts, nor did serologic investigations suggest VDRV transmission to any contacts. This report highlights the need to understand the prevalence and duration of VDRV shedding in granuloma patients and to estimate the risk of VDRV transmission to immune and non-immune contacts.

A case of wild-type rubella-associated cutaneous granuloma in ataxia telangiectasia

Granulomatous skin disease is known to be associated with various primary immunodeficiencies, including ataxia telangiectasia (AT). Recent reports of persistence of live vaccine strain rubella within such cutaneous granulomas have raised concern regarding the safety of vaccination. Here we report a case of cutaneous granuloma in association with AT, demonstrating wild type, rather than vaccine strain rubella. This supports the persistence of rubella as a causative mechanism, but suggests it is not vaccine strain-specific, and thus may impact the decision of those considering not vaccinating this subset of children.

Case Report: Rubella Virus-Induced Cutaneous Granulomas in Two Pediatric Patients With DNA Double Strand Breakage Repair Disorders - Outcome After Hematopoietic Stem Cell Transplantation

We report two patients with DNA repair disorders (Artemis deficiency, Ataxia telangiectasia) with destructive skin granulomas, presumably triggered by live-attenuated rubella vaccinations. Both patients showed reduced naïve T cells. Rapid resolution of skin lesions was observed following hematopoietic stem cell transplantation. However, the patient with AT died due to complications of severe hepatic veno-occlusive disease 6 month after HSCT. Dried blood spots obtained after birth were available from this patient and showed absent T-cell receptor excision circles (TRECs). Therefore, newborn screening may help to prevent patients with moderate T-cell deficiency from receiving live-attenuated rubella vaccine potentially causing granulomas.

SARS-CoV-2 infection in patients with inborn errors of immunity due to DNA repair defects

Clinical information on severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection in patients with inborn errors of immunity (IEI) during the current Coronavirus disease 2019 (COVID-19) pandemic is still limited. Proper DNA repair machinery is required for the development of the adaptive immune system, which provides specific and long-term protection against SARS-CoV-2. This review highlights the impact of SARS-CoV-2 infections on IEI patients with DNA repair disorders and summarizes susceptibility risk factors, pathogenic mechanisms, clinical manifestations and management strategies of COVID-19 in this special patient population.

Physician vaccination practices in mild to moderate inborn errors of immunity and retrospective review of vaccine completeness in IEI: results from the Canadian Immunization Research Network

Background and objectives

Safety and effectiveness concerns may preclude physicians from recommending vaccination in mild/moderate inborn errors of immunity (IEI). This study describes attitudes and practices regarding vaccination among physicians who care for patients with mild/moderate B cell or mild/moderate combined immunodeficiencies (CID) and vaccination completeness among patients diagnosed with IEIs.

Methods

Canadian physicians caring for children with IEI were surveyed about attitudes and practices regarding vaccination in mild/moderate IEI. Following informed consent, immunization records of pediatric patients with IEI evaluated before 7 years of age were reviewed. Vaccine completeness was defined at age 2 years as 4 doses of diphtheria-tetanus-pertussis (DTaP), 3 doses pneumococcal conjugate (PCV), and 1 dose measles-mumps-rubella (MMR) vaccines. At 7 years 5 doses of DTP and 2 doses MMR were required.

Results

Forty-five physicians from 8 provinces completed the survey. Most recommended inactivated vaccines for B cell deficiency: (84% (38/45) and CID (73% (33/45). Fewer recommended live attenuated vaccines (B cell: 53% (24/45), CID 31% (14/45)). Of 96 patients with IEI recruited across 7 centers, vaccination completeness at age 2 was 25/43 (58%) for predominantly antibody, 3/13 (23%) for CID, 7/35 (20%) for CID with syndromic features, and 4/4 (100%) for innate/phagocyte defects. Completeness at age 7 was 15%, 17%, 5%, and 33%, respectively.

Conclusion

Most physicians surveyed recommended inactivated vaccines in children with mild to moderate IEI. Vaccine completeness for all IEI was low, particularly at age 7. Further studies should address the reasons for low vaccine uptake among children with IEI and whether those with mild-moderate IEI, where vaccination is recommended, eventually receive all indicated vaccines.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13223-022-00667-1.

Association of Persistent Rubella Virus With Idiopathic Skin Granulomas in Clinically Immunocompetent Adults

Importance

Vaccine-derived and wild-type rubella virus (RuV) has been identified within granulomas in patients with inborn errors of immunity, but has not been described in granulomas of healthy adults.

Objective

To determine the association between RuV and atypical granulomatous inflammation in immune-competent adults.

Design, Setting, and Participants

This case series, conducted in US academic dermatology clinics from January 2019 to January 2021, investigated the presence of RuV in skin specimens using RuV immunofluorescent staining of paraffin-embedded tissue sections, real-time reverse-transcription polymerase chain reaction, whole-genome sequencing with phylogenetic analyses, and cell culture by the US Centers for Disease Control and Prevention. Rubella immunoglobulin G, immunoglobulin M enzyme-linked immunoassay, and viral neutralization assays were performed for the sera of immunocompetent individuals with treatment refractory cutaneous granulomas and histopathology demonstrating atypical palisaded and necrotizing granulomas. Clinical immune evaluation was performed.

Main Outcomes and Measures

Identification, genotyping, and culture of vaccine-derived and wild-type RuV within granulomatous dermatitis of otherwise clinically immune competent adults.

Results

Of the 4 total immunocompetent participants, 3 (75%) were women, and the mean (range) age was 61.5 (49.0-73.0) years. The RuV capsid protein was detected by immunohistochemistry in cutaneous granulomas. The presence of RuV RNA was confirmed by real-time reverse-transcription polymerase chain reaction in fresh-frozen skin biopsies and whole-genome sequencing. Phylogenetic analysis of the RuV sequences showed vaccine-derived RuV in 3 cases and wild-type RuV in 1. Live RuV was recovered from the affected skin in 2 participants. Immunology workup results demonstrated no primary immune deficiencies.

Conclusions and Relevance

The case series study results suggest that RuV (vaccine derived and wild type) can persist for years in cutaneous granulomas in clinically immunocompetent adults and is associated with atypical (palisaded and necrotizing type) chronic cutaneous granulomas. These findings represent a potential paradigm shift in the evaluation, workup, and management of atypical granulomatous dermatitis and raises questions regarding the potential transmissibility of persistent live RuV.

The natural history of ataxia-telangiectasia (A-T): A systematic review

BACKGROUND

Ataxia-telangiectasia is an autosomal recessive, multi-system, and life-shortening disease caused by mutations in the ataxia-telangiectasia mutated gene. Although widely reported, there are no studies that give a comprehensive picture of this intriguing condition.

OBJECTIVES

Understand the natural history of ataxia-telangiectasia (A-T), as reported in scientific literature.

SEARCH METHODS

107 search terms were identified and divided into 17 searches. Each search was performed in PubMed, Ovid SP (MEDLINE) 1946-present, OVID EMBASE 1980 -present, Web of Science core collection, Elsevier Scopus, and Cochrane Library.

SELECTION CRITERIA

All human studies that report any aspect of A-T.

DATA COLLECTION AND ANALYSIS

Search results were de-duplicated, data extracted (including author, publication year, country of origin, study design, population, participant characteristics, and clinical features). Quality of case-control and cohort studies was assessed by the Newcastle-Ottawa tool. Findings are reported descriptively and where possible data collated to report median (interquartile range, range) of outcomes of interest.

MAIN RESULTS

1314 cases reported 2134 presenting symptoms. The most common presenting symptom was abnormal gait (1160 cases; 188 studies) followed by recurrent infections in classical ataxia-telangiectasia and movement disorders in variant ataxia-telangiectasia. 687 cases reported 752 causes of death among which malignancy was the most frequently reported cause. Median (IQR, range) age of death (n = 294) was 14 years 0 months (10 years 0 months to 23 years 3 months, 1 year 3 months to 76 years 0 months).

CONCLUSIONS

This review demonstrates the multi-system involvement in A-T, confirms that neurological symptoms are the most frequent presenting features in classical A-T but variants have diverse manifestations. We found that most individuals with A-T have life limited to teenage or early adulthood. Predominance of case reports, and case series demonstrate the lack of robust evidence to determine the natural history of A-T. We recommend population-based studies to fill this evidence gap.

Rubella Virus Infected Macrophages and Neutrophils Define Patterns of Granulomatous Inflammation in Inborn and Acquired Errors of Immunity

Rubella virus (RuV) has recently been found in association with granulomatous inflammation of the skin and several internal organs in patients with inborn errors of immunity (IEI). The cellular tropism and molecular mechanisms of RuV persistence and pathogenesis in select immunocompromised hosts are not clear. We provide clinical, immunological, virological, and histological data on a cohort of 28 patients with a broad spectrum of IEI and RuV-associated granulomas in skin and nine extracutaneous tissues to further delineate this relationship. Combined immunodeficiency was the most frequent diagnosis (67.8%) among patients. Patients with previously undocumented conditions, i.e., humoral immunodeficiencies, a secondary immunodeficiency, and a defect of innate immunity were identified as being susceptible to RuV-associated granulomas. Hematopoietic cell transplantation was the most successful treatment in this case series resulting in granuloma resolution; steroids, and TNF-α and IL-1R inhibitors were moderately effective. In addition to M2 macrophages, neutrophils were identified by immunohistochemical analysis as a novel cell type infected with RuV. Four patterns of RuV-associated granulomatous inflammation were classified based on the structural organization of granulomas and identity and location of cell types harboring RuV antigen. Identification of conditions that increase susceptibility to RuV-associated granulomas combined with structural characterization of the granulomas may lead to a better understanding of the pathogenesis of RuV-associated granulomas and discover new targets for therapeutic interventions.

Could β-Lactam Antibiotics Block Humoral Immunity?

It has been reported that treatment with β-lactam antibiotics induces leukopenia and candidemia, worsens the clinical response to anticancer immunotherapy and decreases immune response to vaccination. β-lactamases can cleave β-lactam antibiotics by blocking their activity. Two distincts superfamilies of β-lactamases are described, the serine β-lactamases and the zinc ion dependent metallo-β-lactamases. In human, 18 metallo-β-lactamases encoding genes (hMBLs) have been identified. While the physiological role of most of them remains unknown, it is well established that the SNM1A, B and C proteins are involved in DNA repair. The SNM1C/Artemis protein is precisely associated in the V(D)J segments rearrangement, that leads to immunoglobulin (Ig) and T-cell receptor variable regions, which have a crucial role in the immune response. Thus in humans, SNM1C/Artemis mutation is associated with severe combined immunodeficiency characterized by hypogammaglobulinemia deficient cellular immunity and opportunistic infections. While catalytic site of hMBLs and especially that of the SNM1 family is highly conserved, in vitro studies showed that some β-lactam antibiotics, and precisely third generation of cephalosporin and ampicillin, inhibit the metallo-β-lactamase proteins SNM1A & B and the SNM1C/Artemis protein complex. By analogy, the question arises as to whether β-lactam antibiotics can block the SNM1C/Artemis protein in humans inducing transient immunodeficiency. We reviewed here the literature data supporting this hypothesis based on in silico, in vitro and in vivo evidences. Understanding the impact of β-lactam antibiotics on the immune cell will offer new therapeutic clues and new clinical approaches in oncology, immunology, and infectious diseases.

Stem cell transplantation as treatment for major histocompatibility class I deficiency

Major histocompatibility class I deficiency, due to genetic lesions in TAP1, TAP2, TAPBP, or B2M, manifests with recurrent sinopulmonary infections and granulomatous skin ulceration, and is predominately treated with antimicrobial prophylaxis and chest physiotherapy. One previous report of hematopoietic stem cell transplantation has been described in the literature, demonstrating cure of the immune defect without significant graft-versus-host disease. In this report, we expand the literature on HSCT in MHC-I deficiency with follow-up of the original patient, demonstrating maintained resolution of normal immune function and regression of the granulomatous rash 15 years post-transplant, and describe a further patient with mycobacterial disease whose transplant course was complicated by severe graft-versus-host disease.

Multidisciplinary Management of Ataxia Telangiectasia: Current Perspectives

Ataxia telangiectasia (A-T) is a rare autosomal recessive disease caused by mutations in the ataxia telangiectasia mutated (ATM) gene. In the absence of a family history, the diagnosis of A-T is usually not made until the child is older and symptomatic. Classic A-T is characterized by a constellation of clinical symptoms including progressive ataxia, oculocutaneous telangiectasias and sinopulmonary disease and is usually associated with absence of ATM protein. Other laboratory features associated with A-T include elevated serum levels of alpha-fetoprotein (AFP) and increased chromosomal breakage with in vitro exposure to ionizing radiation. Sinopulmonary symptoms can occur to varying degrees across the lifespan. Some children will also have hypogammaglobulinemia and impaired antibody responses requiring supplemental gamma globulin. People with hypomorphic ATM mutations are often considered to have mild A-T with onset of ataxia and neurological progression occurring later in life with less impairment of the immune system. The risk of malignancy, however, is significantly increased in people with either classic or mild A-T. While hematological malignancies are most common in the first two decades of life, solid organ malignancies become increasingly common during young adulthood. Deterioration of neurologic function with age is associated with dysphagia with aspiration, growth faltering, loss of ambulation and decline in pulmonary function, morbidities that contribute to shortened life expectancy and decreased quality of life. Premature death is often due to malignancies or chronic respiratory insufficiency. A-T is currently managed with supportive care and symptomatic treatment. Current clinical trials, however, represent progress and hope towards disease-modifying therapies for A-T.

Vaccines in Patients with Primary Immune Deficiency

Evaluation of antibodies produced after immunization is central to immune deficiency diagnosis. This includes assessment of responses to routine immunizations as well as to vaccines administered specifically for diagnosis. Here, we present the basic concepts of the humoral immune response and their relevance for vaccine composition and diagnosis of immune deficiency. Current vaccines are discussed, including nonviable protein and glycoprotein vaccines, pure polysaccharide vaccines, polysaccharide-protein conjugate vaccines, and live agent vaccines. Diagnostic and therapeutic applications of vaccine antibody measurement are discussed in depth. Important adverse effects of vaccines are also presented.

Monogenic susceptibility to live viral vaccines

Live attenuated viral vaccines (LAV) have saved millions of lives globally through their capacity to elicit strong, cross-reactive and enduring adaptive immune responses. However, LAV can also act as a Trojan horse to reveal inborn errors of immunity, thereby highlighting important protective elements of the healthy antiviral immune response. In the following article, we draw out these lessons by reviewing the spectrum of LAV-associated disease reported in a variety of inborn errors of immunity. We note the contrast between adaptive disorders, which predispose to both LAV and their wild type counterparts, and defects of innate immunity in which parenterally delivered LAV behave in a particularly threatening manner. Recognition of the underlying pathomechanisms can inform our approach to disease management and vaccination in a wider group of individuals, including those receiving immunomodulators that impact the relevant pathways.

Rubella vaccine-induced granulomas are a novel phenotype with incomplete penetrance of genetic defects in cytotoxicity

BACKGROUND

Rubella virus-induced granulomas have been described in patients with various inborn errors of immunity. Most defects impair T-cell immunity, suggesting a critical role of T cells in rubella elimination. However, the molecular mechanism of virus control remains elusive.

OBJECTIVE

This study sought to understand the defective effector mechanism allowing rubella vaccine virus persistence in granulomas.

METHODS

Starting from an index case with Griscelli syndrome type 2 and rubella skin granulomas, this study combined an international survey with a literature search to identify patients with cytotoxicity defects and granuloma. The investigators performed rubella virus immunohistochemistry and PCR and T-cell migration assays.

RESULTS

This study identified 21 patients with various genetically confirmed cytotoxicity defects, who presented with skin and visceral granulomas. Rubella virus was demonstrated in all 12 accessible biopsies. Granuloma onset was typically before 2 years of age and lesions persisted from months to years. Granulomas were particularly frequent in MUNC13-4 and RAB27A deficiency, where 50% of patients at risk were affected. Although these proteins have also been implicated in lymphocyte migration, 3-dimensional migration assays revealed no evidence of impaired migration of patient T cells. Notably, patients showed no evidence of reduced control of concomitantly given measles, mumps, or varicella live-attenuated vaccine or severe infections with other viruses.

CONCLUSIONS

This study identified lymphocyte cytotoxicity as a key effector mechanism for control of rubella vaccine virus, without evidence for its need in control of live measles, mumps, or varicella vaccines. Rubella vaccine-induced granulomas are a novel phenotype with incomplete penetrance of genetic disorders of cytotoxicity.

Genomic Spectrum and Phenotypic Heterogeneity of Human IL-21 Receptor Deficiency

Biallelic inactivating mutations in IL21R causes a combined immunodeficiency that is often complicated by cryptosporidium infections. While eight IL-21R-deficient patients have been reported previously, the natural course, immune characteristics of disease, and response to hematopoietic stem cell transplantation (HSCT) remain to be comprehensively examined. In our study, we have collected clinical histories of 13 patients with IL-21R deficiency from eight families across seven centers worldwide, including five novel patients identified by exome or NGS panel sequencing. Eight unique mutations in IL21R were identified in these patients, including two novel mutations. Median age at disease onset was 2.5 years (0.5–7 years). The main clinical manifestations were recurrent bacterial (84.6%), fungal (46.2%), and viral (38.5%) infections; cryptosporidiosis-associated cholangitis (46.2%); and asthma (23.1%). Inflammatory skin diseases (15.3%) and recurrent anaphylaxis (7.9%) constitute novel phenotypes of this combined immunodeficiency. Most patients exhibited hypogammaglobulinemia and reduced proportions of memory B cells, circulating T follicular helper cells, MAIT cells and terminally differentiated NK cells. However, IgE levels were elevated in 50% of IL-21R-deficient patients. Overall survival following HSCT (6 patients, mean follow-up 1.8 year) was 33.3%, with pre-existing organ damage constituting a negative prognostic factor. Mortality of non-transplanted patients (n = 7) was 57.1%. Our detailed analysis of the largest cohort of IL-21R-deficient patients to date provides in-depth clinical, immunological and immunophenotypic features of these patients, thereby establishing critical non-redundant functions of IL-21/IL-21R signaling in lymphocyte differentiation, humoral immunity and host defense against infection, and mechanisms of disease pathogenesis due to IL-21R deficiency. Outcome following HSCT depends on prior chronic infections and organ damage, which should thus be considered as early as possible following molecular diagnosis.

Unmasking viral sequences by metagenomic next-generation sequencing in adult human blood samples during steroid-refractory/dependent graft-versus-host disease

BACKGROUND

Viral infections are common complications following allogeneic hematopoietic stem cell transplantation (allo-HSCT). Allo-HSCT recipients with steroid-refractory/dependent graft-versus-host disease (GvHD) are highly immunosuppressed and are more vulnerable to infections with weakly pathogenic or commensal viruses. Here, twenty-five adult allo-HSCT recipients from 2016 to 2019 with acute or chronic steroid-refractory/dependent GvHD were enrolled in a prospective cohort at Geneva University Hospitals. We performed metagenomics next-generation sequencing (mNGS) analysis using a validated pipeline and de novo analysis on pooled routine plasma samples collected throughout the period of intensive steroid treatment or second-line GvHD therapy to identify weakly pathogenic, commensal, and unexpected viruses.

RESULTS

Median duration of intensive immunosuppression was 5.1 months (IQR 5.5). GvHD-related mortality rate was 36%. mNGS analysis detected viral nucleotide sequences in 24/25 patients. Sequences of ≥ 3 distinct viruses were detected in 16/25 patients; Anelloviridae (24/25) and human pegivirus-1 (9/25) were the most prevalent. In 7 patients with fatal outcomes, viral sequences not assessed by routine investigations were identified with mNGS and confirmed by RT-PCR. These cases included Usutu virus (1), rubella virus (1 vaccine strain and 1 wild-type), novel human astrovirus (HAstV) MLB2 (1), classic HAstV (1), human polyomavirus 6 and 7 (2), cutavirus (1), and bufavirus (1).

CONCLUSIONS

Clinically unrecognized viral infections were identified in 28% of highly immunocompromised allo-HSCT recipients with steroid-refractory/dependent GvHD in consecutive samples. These identified viruses have all been previously described in humans, but have poorly understood clinical significance. Rubella virus identification raises the possibility of re-emergence from past infections or vaccinations, or re-infection. Video abstract.

Cutaneous granulomas as the presenting manifestation of Griscelli syndrome type 2

Griscelli syndrome type 2 is a rare autosomal recessive disorder characterized by hypopigmentation, silvery hair, and immunological dysfunction with no primary neurological impairment. We report an 18-month-old girl with Griscelli syndrome type 2 who presented to the dermatology department for cutaneous granulomas that developed following live-attenuated vaccination. Two compound heterozygous variants in the RAB27A gene were subsequently identified. She developed hemophagocytic lymphohistiocytosis, the key immunological concern, at age 5 years.

Histology of Interstitial Lung Disease in Common Variable Immune Deficiency

Interstitial lung disease (ILD) is an important non-infectious complication in several primary immune deficiencies. In common variable immune deficiency (CVID) it is associated with complex clinical phenotypes and adverse outcomes. The histology of ILD in CVID is heterogeneous and mixed patterns are frequently observed within a single biopsy, including non-necrotising granulomatous inflammation, lymphoid interstitial pneumonitis, lymphoid hyperplasia, follicular bronchiolitis, organizing pneumonia, and interstitial fibrosis; ILD has to be differentiated from lymphoma. The term granulomatous-lymphocytic interstitial lung disease (GLILD), coined to describe the histopathological findings within the lungs of patients with CVID with or without multisystem granulomata, is somewhat controversial as pulmonary granulomata are not always present on histology and the nature of infiltrating lymphocytes is variable. In this mini review we summarize the literature on the histology of CVID-related ILD and discuss some of the factors that may contribute to the inter- and intra- patient variability in the histological patterns reported. Finally, we highlight areas for future development. In particular, there is a need for standardization of histological assessments and reporting, together with a better understanding of the immunopathogenesis of CVID-related ILD to resolve the apparent heterogeneity of ILD in this setting and guide the selection of rational targeted therapies in different patients.

Vasculitis as a Major Morbidity Factor in Patients With Partial RAG Deficiency

Vasculitis can be a life-threatening complication associated with high mortality and morbidity among patients with primary immunodeficiencies (PIDs), including variants of severe and combined immunodeficiencies ((S)CID). Our understanding of vasculitis in partial defects in recombination activating gene (RAG) deficiency, a prototype of (S)CIDs, is limited with no published systematic evaluation of diagnostic and therapeutic modalities. In this report, we sought to establish the clinical, laboratory features, and treatment outcome of patients with vasculitis due to partial RAG deficiency. Vasculitis was a major complication in eight (13%) of 62 patients in our cohort with partial RAG deficiency with features of infections and immune dysregulation. Vasculitis occurred early in life, often as first sign of disease (50%) and was complicated by significant end organ damage. Viral infections often preceded the onset of predominately non-granulomatous-small vessel vasculitis. Autoantibodies against cytokines (IFN-α, -ω, and IL-12) were detected in a large fraction of the cases tested (80%), whereas the majority of patients were anti-neutrophil cytoplasmic antibodies (ANCA) negative (>80%). Genetic diagnosis of RAG deficiency was delayed up to 2 years from the onset of vasculitis. Clinical cases with sole skin manifestation responded well to first-line steroid treatment, whereas systemic vasculitis with severe end-organ complications required second-line immunosuppression and/or hematopoietic stem cell transplantation (HSCT) for definitive management. In conclusion, our data suggest that vasculitis in partial RAG deficiency is prevalent among patients with partial RAG deficiency and is associated with high morbidity. Therefore, partial RAG deficiency should be included in the differential diagnosis of patients with early-onset systemic vasculitis. Diagnostic serology may be misleading with ANCA negative findings, and search for conventional autoantibodies should be extended to include those targeting cytokines.

Optimising immunisation in children with 22q11 microdeletion

BACKGROUND

The condition known as 22q11 microdeletion syndrome has a broad phenotypic spectrum, with many affected individuals experiencing mild-to-moderate immunodeficiency. Currently, there are significant variations in live vaccine practices and immunological testing prior to live vaccine administration due to safety concerns and limited established guidelines.

METHODS

Queensland Children's Hospital (QCH) Child Development Unit, offers a state-wide 22q11 microdeletion clinic. This is a retrospective single-centre review, capturing the majority of children with 22q11 microdeletion in Queensland, Australia. We describe the live vaccination status of 134 children, age 0 to 18 years under our care between 2000 and 2018, adverse events following immunisation (AEFI) and the proportion of children who received additional pneumococcal coverage. An immunological investigation pathway prior to live vaccine administration is proposed.

RESULTS

Of the 134 children, 124 were eligible for live vaccinations as per the Australian National Immunisation Program: 82% had received dose one of measles, mumps and rubella (MMR) vaccine, 77% had completed MMR dose two and 66% had completed varicella immunisation. There were no AEFI notifications reported. Of the total sample of children, 18% received a fourth dose of conjugate pneumococcal vaccine (Prevenar 7 or 13) and 16% received a dose of Pneumovax 23 from 4 years of age. Immunology workup practices were demonstrated to vary widely prior to live vaccine administration. Most patients' immune profiles were consistent with mild-to-moderate immunodeficiency.

CONCLUSION

We propose an immunological investigation and vaccination pathway with the aim of providing guidance and consistency to clinicians caring for children with 22q11 microdeletion.

Rubella virus-associated chronic inflammation in primary immunodeficiency diseases

PURPOSE OF THE REVIEW

The aim of this article is to summarize recent data on rubella virus (RuV) vaccine in chronic inflammation focusing on granulomas in individuals with primary immunodeficiencies (PIDs).

RECENT FINDINGS

The live attenuated RuV vaccine has been recently associated with cutaneous and visceral granulomas in children with various PIDs. RuV vaccine strain can persist for decades subclinically in currently unknown body site(s) before emerging in granulomas. Histologically, RuV is predominately localized in M2 macrophages in the granuloma centers. Multiple mutations accumulate during persistence resulting in emergence of immunodeficiency-related vaccine-derived rubella viruses (iVDRVs) with altered immunological, replication, and persistence properties. Viral RNA was detected in granuloma biopsies and nasopharyngeal secretions and infectious virus were isolated from the granuloma lesions. The risk of iVDRV transmissibility to contacts needs to be evaluated. Several broad-spectrum antiviral drugs have been tested recently but did not provide significant clinical improvement. Hematopoietic stem cell transplantation remains the only reliable option for curing chronic RuV-associated granulomas in PIDs.

SUMMARY

Persistence of vaccine-derived RuVs appears to be a crucial factor in a significant proportion of granulomatous disease in PIDs. RuV testing of granulomas in PID individuals might help with case management.

Immune dysregulation in patients with RAG deficiency and other forms of combined immune deficiency

Traditionally, primary immune deficiencies have been defined based on increased susceptibility to recurrent and/or severe infections. However, immune dysregulation, manifesting with autoimmunity or hyperinflammatory disease, has emerged as a common feature. This is especially true in patients affected by combined immune deficiency (CID), a group of disorders caused by genetic defects that impair, but do not completely abolish, T-cell function. Hypomorphic mutations in the recombination activating genes RAG1 and RAG2 represent the prototype of the broad spectrum of clinical and immunological phenotypes associated with CID. The study of patients with RAG deficiency and with other forms of CID has revealed distinct abnormalities in central and peripheral T- and B-cell tolerance as the key mechanisms involved in immune dysregulation. Understanding the pathophysiology of autoimmunity and hyperinflammation in these disorders may also permit more targeted therapeutic interventions.

The Safety and Efficacy of Live Viral Vaccines in Patients With Cartilage-Hair Hypoplasia

Background

Live viral vaccines are generally contraindicated in patients with combined immunodeficiency including cartilage-hair hypoplasia (CHH); however, they may be tolerated in milder syndromes. We evaluated the safety and efficacy of live viral vaccines in patients with CHH.

Methods

We analyzed hospital and immunization records of 104 patients with CHH and measured serum antibodies to measles, mumps, rubella, and varicella zoster virus (VZV) in all patients who agreed to blood sampling (n = 50). We conducted a clinical trial (ClinicalTrials.gov identifier: NCT02383797) of live VZV vaccine on five subjects with CHH who lacked varicella history, had no clinical symptoms of immunodeficiency, and were seronegative for VZV; humoral and cellular immunologic responses were assessed post-immunization.

Results

A large proportion of patients have been immunized with live viral vaccines, including measles-mumps-rubella (MMR) (n = 40, 38%) and VZV (n = 10, 10%) vaccines, with no serious adverse events. Of the 50 patients tested for antibodies, previous immunization has been documented with MMR (n = 22), rubella (n = 2) and measles (n = 1) vaccines. Patients with CHH demonstrated seropositivity rates of 96%/75%/91% to measles, mumps and rubella, respectively, measured at a medium of 24 years post-immunization. Clinical trial participants developed humoral and cellular responses to VZV vaccine. One trial participant developed post-immunization rash and knee swelling, both resolved without treatment.

Conclusion

No serious adverse events have been recorded after immunization with live viral vaccines in Finnish patients with CHH. Patients generate humoral and cellular immune response to live viral vaccines. Immunization with live vaccines may be considered in selected CHH patients with no or clinically mild immunodeficiency.

Immunodeficiency in cartilage-hair hypoplasia: Pathogenesis, clinical course and management

Cartilage-hair hypoplasia (CHH) is an autosomal recessive syndromic immunodeficiency with skeletal dysplasia, short stature, hypotrichosis, variable degree of immune dysfunction and increased incidence of anaemia, Hirschsprung disease and malignancy. CHH is caused by variants in the RMRP gene, encoding the untranslated RNA molecule of the mitochondrial RNA-processing endoribonuclease, which participates in for example cell cycle regulation and telomere maintenance. Recent studies have expanded our understanding of the complex pathogenesis of CHH. Immune dysfunction has a major impact on clinical course and prognosis. Clinical features of immune dysfunction are highly variable, progressive and include infections, lung disease, immune dysregulation and malignancy. Mortality is increased compared with the general population, due to infections, malignancy and pulmonary disease. Several risk factors for early mortality have been reported in the Finnish CHH cohort and can be used to guide management. Newborn screening for severe combined immunodeficiency can possibly be of prognostic value in CHH. Regular follow-up by a multidisciplinary team should be implemented to address immune dysfunction in all patients with CHH, also in asymptomatic cases. Haematopoietic stem cell transplantation can cure immune dysfunction, but its benefits in mildly symptomatic patients with CHH remain debatable. Further research is needed to understand the mechanisms behind the variability of clinical features, to search for potential molecular treatment targets, to examine and validate risk factors for early mortality outside the Finnish CHH cohort and to develop management guidelines. This review focuses on the pathogenesis, clinical course and management of CHH.

Granulomatous Liver Disease in Ataxia-Telangiectasia With the Hyper-IgM Phenotype: A Case Report

Ataxia-telangiectasia (A-T) is an autosomal recessive disorder characterized by neurodegeneration, combined immunodeficiency, and oculocutaneous telangiectasia. The hyper-IgM phenotype of A-T, correlating with a class-switch recombination defect, IgG and IgA deficiency, T helper and B cell lymphopenia, immune dysregulation, proinflammatory immune response, autoimmune disease, and a high risk of lymphomagenesis. Progressive liver disease is a hallmark of classical A-T with the hyper-IgM phenotype and manifests as non-alcoholic hepatic steatosis and fibrosis. We report a case of a 17-year-old male A-T patient, in whom a progressive granulomatous liver disease with portal hypertension, has led to massive splenomegaly and hypersplenism, metabolic liver insufficiency, bleeding from esophageal varices and pancytopenia. In this patient, an unusual severe disease course with a highly variable constellation of A-T symptomatology includes granulomatous skin, visceral, and internal organs disease with liver involvement. The liver disease is associated with the hyper-IgM immunophenotype and escalating neurodegeneration, creating a vicious circle of immune deficiency, permanent systemic inflammatory response, and organ-specific immunopathology.

Infectious vaccine-derived rubella viruses emerge, persist, and evolve in cutaneous granulomas of children with primary immunodeficiencies

Rubella viruses (RV) have been found in an association with granulomas in children with primary immune deficiencies (PID). Here, we report the recovery and characterization of infectious immunodeficiency-related vaccine-derived rubella viruses (iVDRV) from diagnostic skin biopsies of four patients. Sequence evolution within PID hosts was studied by comparison of the complete genomic sequences of the iVDRVs with the genome of the vaccine virus RA27/3. The degree of divergence of each iVDRV correlated with the duration of persistence indicating continuous intrahost evolution. The evolution rates for synonymous and nonsynonymous substitutions were estimated to be 5.7 x 10-3 subs/site/year and 8.9 x 10-4 subs/site/year, respectively. Mutational spectra and signatures indicated a major role for APOBEC cytidine deaminases and a secondary role for ADAR adenosine deaminases in generating diversity of iVDRVs. The distributions of mutations across the genes and 3D hotspots for amino acid substitutions in the E1 glycoprotein identified regions that may be under positive selective pressure. Quasispecies diversity was higher in granulomas than in recovered infectious iVDRVs. Growth properties of iVDRVs were assessed in WI-38 fibroblast cultures. None of the iVDRV isolates showed complete reversion to wild type phenotype but the replicative and persistence characteristics of iVDRVs were different from those of the RA27/3 vaccine strain, making predictions of iVDRV transmissibility and teratogenicity difficult. However, detection of iVDRV RNA in nasopharyngeal specimen and poor neutralization of some iVDRV strains by sera from vaccinated persons suggests possible public health risks associated with iVDRV carriers. Detection of IgM antibody to RV in sera of two out of three patients may be a marker of virus persistence, potentially useful for identifying patients with iVDRV before development of lesions. Studies of the evolutionary dynamics of iVDRV during persistence will contribute to development of infection control strategies and antiviral therapies.

Life-Threatening Infections Due to Live-Attenuated Vaccines: Early Manifestations of Inborn Errors of Immunity

Live-attenuated vaccines (LAVs) can protect humans against 12 viral and three bacterial diseases. By definition, any clinical infection caused by a LAV that is sufficiently severe to require medical intervention attests to an inherited or acquired immunodeficiency that must be diagnosed or identified. Self-healing infections can also result from milder forms of immunodeficiency. We review here the inherited forms of immunodeficiency underlying severe infections of LAVs. Inborn errors of immunity (IEIs) underlying bacille Calmette-Guérin (BCG), oral poliovirus (OPV), vaccine measles virus (vMeV), and oral rotavirus vaccine (ORV) disease have been described from 1951, 1963, 1966, and 2009 onward, respectively. For each of these four LAVs, the underlying IEIs show immunological homogeneity despite genetic heterogeneity. Specifically, BCG disease is due to inborn errors of IFN-γ immunity, OPV disease to inborn errors of B cell immunity, vMeV disease to inborn errors of IFN-α/β and IFN-λ immunity, and ORV disease to adaptive immunity. Severe reactions to the other 11 LAVs have been described yet remain "idiopathic," in the absence of known underlying inherited or acquired immunodeficiencies, and are warranted to be the focus of research efforts. The study of IEIs underlying life-threatening LAV infections is clinically important for the affected patients and their families, as well as immunologically, for the study of the molecular and cellular basis of host defense against both attenuated and parental pathogens.

Hematopoietic Stem Cell Transplantation for Combined Immunodeficiencies, on Behalf of IEWP-EBMT

Combined immunodeficiencies (CIDs) are a clinically and genetically heterogeneous group of primary immunodeficiencies (PIDs) that affect T-lymphocyte immunity with abnormal development or function. As compared to severe combined immune deficiencies (SCID), these patients are usually diagnosed later. They display a broad infectious susceptibility; immune dysregulation manifestations and chronic lymphoproliferation are also frequent. These complications and their specific treatments can lead to persistent damage to several organs. Prognosis of CIDs is worse as compared to other PIDs. The curative treatment is usually hematopoietic stem cell transplantation (HSCT), but difficult questions remain regarding the definitive indication of HSCT and its timing; the final decision depends on a conjunction of factors such as immunological parameters, severity of clinical manifestations, and natural history of the disease, when molecular diagnosis is known. CD40L deficiency, a CID caused by mutations in CD40LG gene, well illustrates the dilemma between HSCT vs. long-term supportive treatment. This disease leads to higher risk of developing infections from bacterial and intracellular pathogens, especially Pneumocystis and Cryptosporidium spp. While supportive care allows improved survival during childhood, organ damages may develop with increasing age, mainly chronic lung disease and biliary tract disease (secondary to Cryptosporidium spp. infection) that may evolve later to sclerosing cholangitis, a severe complication associated with increased mortality. Early HSCT before organ damage development is associated with best survival and cure rate, while HSCT remains a risky therapeutic option for older patients, for those with organ damage, especially severe liver disease, and/or for those with limited or no donor availability. Prospective studies are needed to analyze risks of HSCT compared to those of life-long supportive therapy, including quality of life measures.