Human Genetic and Immunological Determinants of SARS-CoV-2 Infection and Multisystem Inflammatory Syndrome in Children.

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) induces pneumonia and acute respiratory failure in Coronavirus Disease 2019 (COVID-19) patients with inborn errors of immunity to type I interferon (IFN-I). The impact of SARS-CoV-2 infection varies widely, ranging from mild respiratory symptoms to life-threatening illness and organ failure, with a higher incidence in men than in women. Approximately 3 to 5% of critical COVID-19 patients under 60 and a smaller percentage of elderly patients exhibit genetic defects in IFN-I production, including X-chromosome-linked TLR7 and autosomal TLR3 deficiencies. Around 15 to 20% of cases over 70 years old, and a smaller percentage of younger patients, present with preexisting autoantibodies neutralizing type I interferons. Additionally, innate errors affecting the control of the response to type I interferon have been associated with pediatric multisystem inflammatory syndrome (MIS-C). Several studies have described rare errors of immunity, such as XIAP deficiency, CYBB, SOCS1, OAS1/2, and RNASEL, as underlying factors in MIS-C susceptibility. However, further investigations in expanded patient cohorts are needed to validate these findings and pave the way for new genetic approaches to MIS-C. This review aims to present recent evidence from the scientific literature on genetic and immunological abnormalities predisposing individuals to critical SARS-CoV-2 infection through IFN-I. We will also discuss multisystem inflammatory syndrome in children (MIS-C). Understanding the immunological mechanisms and pathogenesis of severe COVID-19 may inform personalized patient care and population protection strategies against future serious viral infections.

Clinical and Immunological Features of 96 Moroccan Children with SCID Phenotype: Two Decades' Experience.

Severe combined immunodeficiency (SCID) is a heterogeneous group of primary immunodeficiency diseases (PIDs) characterized by a lack of autologous T lymphocytes. This severe PID is rare, but has a higher prevalence in populations with high rates of consanguinity. The epidemiological, clinical, and immunological features of SCIDs in Moroccan patients have never been reported. The aim of this study was to provide a clinical and immunological description of SCID in Morocco and to assess changes in the care of SCID patients over time. This cross-sectional retrospective study included 96 Moroccan patients referred to the national PID reference center at Casablanca Children's Hospital for SCID over two decades, from 1998 to 2019. The case definition for this study was age < 2 years, with a clinical phenotype suggestive of SCID, and lymphopenia, with very low numbers of autologous T cells, according to the IUIS Inborn Errors of Immunity classification. Our sample included 50 male patients, and 66% of the patients were born to consanguineous parents. The median age at onset and diagnosis were 3.3 and 6.5 months, respectively. The clinical manifestations commonly observed in these patients were recurrent respiratory tract infection (82%), chronic diarrhea (69%), oral candidiasis (61%), and failure to thrive (65%). The distribution of SCID phenotypes was as follows: T-B-NK+ in 44.5%, T-B-NK- in 32%, T-B+NK- in 18.5%, and T-B+NK+ in 5%. An Omenn syndrome phenotype was observed in 15 patients. SCID was fatal in 84% in the patients in our cohort, due to the difficulties involved in obtaining urgent access to hematopoietic stem cell transplantation, which, nevertheless, saved 16% of the patients. The autosomal recessive forms of the clinical and immunological phenotypes of SCID, including the T-B-NK+ phenotype in particular, were more frequent than those in Western countries. A marked improvement in the early detection of SCID cases over the last decade was noted. Despite recent progress in SCID diagnosis, additional efforts are required, for genetic confirmation and particularly for HSCT.

Case Report of Two Independent Moroccan Families with Syndromic Epidermodysplasia Verruciformis and STK4 Deficiency.

Epidermodysplasia verruciformis (EV) is a rare genodermatosis caused by ß-human papillomaviruses (HPV) in immunodeficient patients. EV is characterized by flat warts and pityriasis-like lesions and might be isolated or syndromic, associated with some other infectious manifestations. We report here three patients from two independent families, with syndromic EV for both of them. By whole exome sequencing, we found that the patients carry new homozygous variants in STK4, both leading to a premature stop codon. STK4 deficiency causes a combined immunodeficiency characterized by a broad infectious susceptibility to bacteria, viruses, and fungi. Auto-immune manifestations were also reported. Deep immunophenotyping revealed multiple cytopenia in the three affected patients, in particular deep CD4+ T cells deficiency. We report here the fourth and the fifth cases of the syndromic EV due to STK4 deficiency.

Phenotypes of 126 Moroccan HIES patients according to NIH Score.

INTRODUCTION: Hyper-IgE syndrome is a group of inborn errors of immunity, some of which are syndromic, characterized clinically by the classic triad of chronic eczema, cutaneous and/or pulmonary staphylococcal infections and high serum IgE concentrations (> 2000 IU/ml or > 10 x normal for age). AIM: We report here the clinical and immunological aspects of Moroccan patients presenting probable or possible HIES according to NIH-HIES score. METHODS: This retrospective study covers the period from 1998 to 2023 and includes Moroccan patients with a clinical presentation suggestive of HIES (skin and/or pulmonary infections, eczema, high IgE levels) and an NIH score ≥ 20. We attempted to classify the patients phenotypically according to the 2022 IUIS IEI Expert Committee classification. RESULTS: Median age at symptom onset was 0.5 years and median age at diagnosis was 5.5 years. The main clinical signs were eczema (66%), skin abscesses (32.5%), pneumonia (32.5%), otitis (20%), mucocutaneous candidiasis (19%), diarrhea (12%), facial dysmorphism (10.3%), lymphadenopathy (9.5%), bronchial dilation (8%), pneumatoceles (8%), conjunctivitis (7.1%), rhinitis (6.3%), psychomotor delay (5.6%), pathological fractures (4%), retention of deciduous teeth (4%), cognitive delay (3.2%). CONCLUSION: This is the first clinical description of a cohort of Moroccan patients presenting HIES according to NIH criteria. Phenotype can sometimes orient towards identification of the mutated gene, but the overlapping clinical signs make molecular analysis necessary for genetic counseling and appropriate treatment.

Effectiveness of natural immune protection against COVID-19 reinfection: systematic review with meta-analysis.

INTRODUCTION: The future of the COVID-19 pandemic depends on the evolution of the virus and immune protection stimulated by vaccination or upon exposure to natural infection. While most research focuses on vaccine efficacy, data remain unclear on the efficacy and duration of natural immune protection against infection. AIM: In this article, we aim to determine the efficacy of natural immune protection against reinfection with COVID-19 or severe COVID-19. METHODS: We performed a systematic review of available studies in electronic databases followed by a meta-analysis to determine the efficacy of natural immune protection against COVID-19 reinfection and severe infection. RESULTS: Of the 414 studies identified for the full review, 8 studies met the inclusion criteria and were analyzed. The total number of individuals participating in the 8 studies included 19,837,147 people. Individuals with a history of SARS-CoV-2 infection (1,9% [0,6%-3,1%]) had a lower rate of infection than individuals without a history of infection (7,1% [3,9%-10,1%]). The mean efficacy of natural immune protection against reinfection was 84,7% [78,5%-90,9%], while the mean efficacy of natural immune protection against severe COVID-19 infection was 96,9% [94%-99,6%]. CONCLUSION: These results indicate that natural immune protection against reinfection is high, particularly against severe COVID-19. However, further research is needed to determine the duration of natural immune protection and the impact of different variants of SARS-CoV-2.

Diagnostic guidance for hereditary neutropenia in children: Narrative literature review.

In the era of genomics, orientation in the face of hereditary neutropenia still requires, first and foremost, a good clinical and cytological analysis. The thirty responsible genes now explain 60% of congenital neutropenia. These are rare since they are only found in 1‰ of all congenital neutropenia, estimated at 1% of the population. The clinical examination looks for phenotypes associated with syndromic hereditary neutropenia and cytology will guide this etiological research thanks to the data collected from blood count and bone marrow analysis. The objective of this narrative literature review is to provide an overview of the most recent literature regarding acquired and congenital chronic neutropenia and will provide a decision tree to guide towards aetiology. This will allow a better discussion with geneticists even if the genotype-phenotype correlation is not very strong.

Clinical and serological correlation of systemic sclerosis in Moroccan patients.

Objective: SSc is a CTD characterized by excessive fibrosis of the skin and internal organs, along with microvascular damage, and is often associated with typical autoantibodies. The aim of this study was to analyse the correlation between specific autoantibody profiles, clinical and paraclinical features in Moroccan patients with SSc. Methods: We analysed the presence of specific autoantibodies in 46 SSc patients using IIF on HEp-2 cells and immunodot. We then correlated the types of autoantibodies with clinical and laboratory manifestations. Results: Among our patients, 86.9% were females. The mean age of patients at diagnosis was 50.21 years, with an average delay to diagnosis of 5 years. The main clinical manifestations found were RP (89.2%), sclerodactyly (84.8%), proximal scleroderma (67.4%), gastrointestinal involvement (50%) and interstitial lung disease (30.4%). According to the specific autoantibody profile, 14 patients were anti-topo I positive (30.4%), 8 anti-RNP (68 kDa/A/C) positive (17.4%) and 6 anti-RNA polymerase III positive (13%). We found a significant association of anti-RNA polymerase III with sclerodactyly and pulmonary arterial hypertension (P < 0.05). We also found an association between anti-topo I and interstitial lung disease in 30.4% of patients. There was no significant association between the positivity for the autoantibodies and other diagnosed clinical manifestations. Conclusion: Some clinical manifestations of SSc might be positively correlated with the presence of specific autoantibodies. Environmental factors, ethnicity and gene interaction might also influence this correlation.

Atypical Cutaneous Viral Infections Reveal an Inborn Error of Immunity in 8 Patients.

Unusual viral skin infections might be the first clinical manifestation in children with an inborn error of immunity (IEI). We performed a prospective study from 1 October 2017 to 30 September 2021, at the Department of Pediatric Infectious Diseases and Clinical Immunity of Ibn Rochd University Hospital-Casablanca. During this period, on 591 patients newly diagnosed with a probable IEI, eight of them (1.3%), from six independent families, had isolated or syndromic unusual viral skin infections, which were either profuse, chronic or recurrent infections, and resistant to any treatment. The median age of disease onset was nine years old and all patients were born from a first-degree consanguineous marriage. By combining clinical, immunological and genetic investigations, we identified GATA2 deficiency in one patient with recalcitrant profuse verrucous lesions and monocytopenia (1/8) and STK4 deficiency in two families with HPV lesions, either flat or common warts, and lymphopenia (2/8), as previously reported. We also identified COPA deficiency in twin sisters with chronic profuse Molluscum contagiosum lesions, pulmonary diseases and microcytic hypochromic anemia (2/8). Finally, we also found one patient with chronic profuse MC lesions and hyper IgE syndrome, (1/8) and two patients with either recalcitrant profuse verrucous lesions or recurrent post-herpetic erythema multiforme and a combined immunodeficiency (2/8) with no genetic defect identified yet. Raising clinicians awareness that infectious skin diseases might be the consequence of an inborn error of immunity would allow for optimized diagnosis, prevention and treatment of patients and their families.

HPV-Related Skin Phenotypes in Patients with Inborn Errors of Immunity.

Patients with inborn errors of immunity (IEI) are prone to develop infections, either due to a broad spectrum of pathogens or to only one microbe. Since skin is a major barrier tissue, cutaneous infections are among the most prevalent in patients with IEI due to high exposures to many microbes. In the general population, human papillomaviruses (HPVs) cause asymptomatic or self-healing infections, but, in patients with IEI, unusual clinical expression of HPV infection is observed ranging from epidermodysplasia verruciformis (EV) (a rare disease due to ß-HPVs) to profuse, persistent, and recalcitrant warts (due to α-, γ-, and µ-HPVs) or even tree man syndrome (due to HPV2). Mutations in EVER1, EVER2, and CIB1 are associated with EV phenotype; GATA2, CXCR4, and DOCK8 mutations are typically associated with extensive HPV infections, but there are several other IEI that are less frequently associated with severe HPV lesions. In this review, we describe clinical, immunological, and genetic patterns of IEI related to severe HPV cutaneous infections and propose an algorithm for diagnosis of IEI with severe warts associated, or not, with lymphopenia.

Human T-bet governs the generation of a distinct subset of CD11chighCD21low B cells.

High-level expression of the transcription factor T-bet characterizes a phenotypically distinct murine B cell population known as "age-associated B cells" (ABCs). T-bet-deficient mice have reduced ABCs and impaired humoral immunity. We describe a patient with inherited T-bet deficiency and largely normal humoral immunity including intact somatic hypermutation, affinity maturation and memory B cell formation in vivo, and B cell differentiation into Ig-producing plasmablasts in vitro. Nevertheless, the patient exhibited skewed class switching to IgG1, IgG4, and IgE, along with reduced IgG2, both in vivo and in vitro. Moreover, T-bet was required for the in vivo and in vitro development of a distinct subset of human B cells characterized by reduced expression of CD21 and the concomitantly high expression of CD19, CD20, CD11c, FCRL5, and T-bet, a phenotype that shares many features with murine ABCs. Mechanistically, human T-bet governed CD21loCD11chi B cell differentiation by controlling the chromatin accessibility of lineage-defining genes in these cells: FAS, IL21R, SEC61B, DUSP4, DAPP1, SOX5, CD79B, and CXCR4. Thus, human T-bet is largely redundant for long-lived protective humoral immunity but is essential for the development of a distinct subset of human CD11chiCD21lo B cells.

Severe Combined Immunodeficiency Disorder due to a Novel Mutation in Recombination Activation Gene 2: About 2 Cases.

Severe combined immunodeficiency (SCID) comprises a heterogeneous group of inherited immunologic disorders with profound defects in cellular and humoral immunity. SCID is the most severe PID and constitutes a pediatric emergency. Affected children are highly susceptible to bacterial, viral, fungal, and opportunistic infections with life-threatening in the absence of hematopoietic stem cell transplantation. We report here two cases of SCID. The first case is a girl diagnosed with SCID at birth based on her family history and lymphocyte subpopulation typing. The second case is a 4-month-old boy with a history of recurrent opportunistic infections, BCGitis, and failure to thrive, and the immunology workup confirms a SCID phenotype. The genetic study in the two cases revealed a novel mutation in the RAG2 gene, c.826G > A (p.Gly276Ser), in a homozygous state. The novel mutation in the RAG2 gene identified in our study may help the early diagnosis of SCID.

A laboratory-based study of COVID-19 in Casablanca, Morocco.

Given the spread of coronavirus disease 2019 (COVID-19) and its impact on human health, laboratory confirmation of diagnosis is essential. This study examined the contribution of laboratory diagnosis to the detection of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) in the diagnosis of COVID-19, taking into account patient risk of exposure to SARS-CoV-2, clinical symptoms and comorbidities. A cross-sectional, laboratory-based study was carried out from 1 April 2020 to 30 April 2020 at the National Reference Laboratory in Morocco using nasopharyngeal samples from patients admitted to the Cheikh Khalifa International University Hospital or other hospitals in Casablanca. A one-step reverse transcription real-time polymerase chain reaction (RT-PCR) was used to detect the presence of the SARS-CoV-2 genome. A national epidemiological investigation form was used to analyze patient exposure risk, clinical symptoms and comorbidities. A total of 793 samples from 375 patients were analyzed and 1150 RT-PCR tests were conducted; 116 patients (30.93%) were COVID-19 positive. Travel to a risk zone, contact with a confirmed COVID-19 case and contact with a person who had been in a risk zone were significantly associated with being positive for COVID-19. Fever and cough were the main symptoms; 7.76 % of positive patients were asymptomatic. This is the first laboratory-based study in Morocco for the diagnosis of COVID-19. Laboratory diagnosis of COVID-19 by RTPCR associated with knowledge of exposure risk factors and clinical symptoms and comorbidities remains essential for clinicians for early, appropriate medical management COVID-19 patients.

Hematological and biochemical abnormalities associated with severe forms of COVID-19: A retrospective single-center study from Morocco.

Since December 2019, the coronavirus disease (COVID-19) pandemic has catapulted the world into a marked health crisis, with over 29 million cases and >930,000 deaths. To better detect affected individuals at an early stage and stop disease progression to an advanced stage, several studies have been conducted to identify the clinical, biological, and radiological characteristics of COVID-19. This study aimed to enrich the literature by critically analyzing the clinical and biological characteristics of 134 patients from the North African Mediterranean region, including numerous genetic, epigenetic, and environmental factors that may influence disease evolution. This single-center retrospective study included all patients older than 18 years confirmed to have COVID-19 and hospitalized at the Cheikh Khalifa University Hospital affiliated with Mohammed VI University of Health Sciences, Casablanca, Morocco. Clinical, demographic, and biological data were analyzed in a cohort of severe and non-severe patients. Univariate analysis was performed to identify factors predictive of severity. There were 134 patients: the median age was 53 years, and 54.5% were male. Of these, 89 had mild to moderate disease; 45 had severe to critical disease, of which 14 died and 31 survived. Advanced age, presence of comorbidities, male sex, and infection in ethnic or family groups were risk factors for progression to severe disease. The presence of abnormalities in the following parameters were strongly associated with progression to severe disease: white blood cells (WBC), neutrophils, lymphocytes, C-reactive protein (CRP), procalcitonin, D-dimers, lactate dehydrogenase (LDH), ferritin, creatinine, aspartate aminotransferase (ASAT), and alanine aminotransferase (ALAT) during both admission and hospitalization. Based on these results and an extensive literature review, we recommend that clinicians closely monitor the biological parameters identified herein and perform immunological and genetic studies.

[Clinical and immunological profile of 15 Moroccan patients with Hyper IgM syndrome]. / Le profil clinique et immunologique de 15 patients Marocains atteints de syndrome hyper IgM.

Hyper IgM syndrome is a well known genetic (primary) immunodeficiency disorder which was first described in 1961. It is caused by B lymphocyte deficiency characterized by normal or elevated serum IgM levels and low or zero levels of IgG, IgA, IgE resulting from isotype-switching deficiency. Clinical manifestations are dominated by recurrent infections, especially involving the digestive tube of the ENT sphere and the lungs. This syndrome is caused by B-cell immunoglobulin class switch deficiency and decreased capacity to induce proliferation of T lymphocytes. The net result of these deficiencies is reflected in increased susceptibility to Pneumocystis jiroveci, Cryptosporidium spp and other intracellular organisms as well as high rate of bacterial and viral infections. This study aimed to illustrate the importance of understanding the pathophysiological mechanisms associated with this increased susceptibility to infections in order to allow a better diagnosis and therapy in patients with Hyper IgM syndrome (HIM).