The Middle East and North Africa Diagnosis and Management Guidelines for Inborn Errors of Immunity.

Human inborn errors of immunity (IEI) are a group of 485 distinct genetic disorders affecting children and adults. Signs and symptoms of IEI are heterogeneous, and accurate diagnosis can be challenging and depends on the available human expertise and laboratory resources. The Middle East and North Africa (MENA) region has an increased prevalence of IEI because of the high rate of consanguinity with a predominance of autosomal recessive disorders. This area also exhibits more severe disease phenotypes compared with other regions, probably due to the delay in diagnosis. The MENA-IEI registry network has designed protocols and guidelines for the diagnosis and treatment of IEI, taking into consideration the variable regional expertise and resources. These guidelines are primarily meant to improve the care of patients within the region, but can also be followed in other regions with similar patient populations.

Simple Measurement of IgA Predicts Immunity and Mortality in Ataxia-Telangiectasia.

Patients with ataxia-telangiectasia (A-T) suffer from progressive cerebellar ataxia, immunodeficiency, respiratory failure, and cancer susceptibility. From a clinical point of view, A-T patients with IgA deficiency show more symptoms and may have a poorer prognosis. In this study, we analyzed mortality and immunity data of 659 A-T patients with regard to IgA deficiency collected from the European Society for Immunodeficiencies (ESID) registry and from 66 patients with classical A-T who attended at the Frankfurt Goethe-University between 2012 and 2018. We studied peripheral B- and T-cell subsets and T-cell repertoire of the Frankfurt cohort and survival rates of all A-T patients in the ESID registry. Patients with A-T have significant alterations in their lymphocyte phenotypes. All subsets (CD3, CD4, CD8, CD19, CD4/CD45RA, and CD8/CD45RA) were significantly diminished compared to standard values. Patients with IgA deficiency (n = 35) had significantly lower lymphocyte counts compared to A-T patients without IgA deficiency (n = 31) due to a further decrease of naïve CD4 T-cells, central memory CD4 cells, and regulatory T-cells. Although both patient groups showed affected TCR-ß repertoires compared to controls, no differences could be detected between patients with and without IgA deficiency. Overall survival of patients with IgA deficiency was significantly diminished. For the first time, our data show that patients with IgA deficiency have significantly lower lymphocyte counts and subsets, which are accompanied with reduced survival, compared to A-T patients without IgA deficiency. IgA, a simple surrogate marker, is indicating the poorest prognosis for classical A-T patients. Both non-interventional clinical trials were registered at clinicaltrials.gov 2012 (Susceptibility to infections in ataxia-telangiectasia; NCT02345135) and 2017 (Susceptibility to Infections, tumor risk and liver disease in patients with ataxia-telangiectasia; NCT03357978).

Primary Immunodeficiencies: Epidemiology in the Maghreb.

INTRODUCTION: Primary Immunodeficiency (PIDs) is a set of 330 rare hereditary diseases that increase susceptibility to infections, allergies, autoimmunity, and neoplasia. North American registries give higher prevalence than Maghreb ones, whereas consanguinity is high. The purpose of this study is to compare prevalence and coverage rate of Maghreb PID registries with estimates based on USA. METHODS: We searched the prevalence of PIDs in the Maghreb registers. Next, we estimated the expected values based on recent publications. Finally, we calculated the coverage rate of the Maghreb registries compared to the new estimates and we evaluated the impact of consanguinity. RESULTS: The total number is N1 = 2456 patients. The current Maghreb PID Prevalence is 2.56 / 100,000 inhabitants (population of 94,804,694 Million in 2017). Tunisia leads with a prevalence of 8.70 followed by Morocco 2.09, Libya 1.65 and Algeria 1.46/100.000 habitants. We did not find values for Mauritania. If we extrapolate the prevalence of the USA to the Maghreb population, the number of patients in the Maghreb would be N2 = 27,588 and the coverage rate (N1 / N2) would be 8.90%. This low coverage rate is however better than the World average (1.21%), that of Latin America 1.19% and Africa 0.36%. The Maghreb prevalence is close to that of the Arab world 2.04 / 100,000 (population of 391,449,544 in 2017). Using the incidence found in the USA, the number of patients would be 9765 new patients per year in the Maghreb and 40,319 in Arab countries. CONCLUSION: PID Maghreb patients number is very low compared to global estimates, whereas consanguinity is very high. Special attention should be given to PIDs by governments and research teams in this region.

Allergy and immunology in Africa: Challenges and unmet needs.

The tremendous increase in allergy in the African continent cannot simply be explained by the change in public hygiene. There are many "prehygiene" communities with sewage-contaminated water supplies, helminth infestations, bare footedness, and poor housing, and still there is a high prevalence of allergic disease. Africans can be exposed to many risk factors facilitating severe asthma and wheezing, including airborne viruses, smoke, indoor dampness, cockroaches, and poor access to health care. Although the reporting on food allergy is inadequate to perform systematic reviews or meta-analyses, the available data suggest that food allergy is underdiagnosed. The rate of new HIV infections in high-prevalence settings in Africa remains unacceptably high. Although the annual number of new HIV infections in Sub-Saharan Africa has decreased lately, new HIV infections in the Middle East and North Africa region have increased; however, the current prevalence of 0.1% is still among the lowest globally. Africa is densely populated, and consanguineous mating is high in some areas of North and Sub-Saharan Africa. This allows for emergence of many autosomal recessive primary immunodeficiency diseases. There is urgent need for the establishment of primary immunodeficiency disease registries, stem cell transplantation facilities, and neonatal screening programs. To address these expanding problems and perform local cutting-edge research, Africans need to be empowered by motivated governments, dedicated funds, and compassionate scientific partnership.

Emerging Infections and Pertinent Infections Related to Travel for Patients with Primary Immunodeficiencies.

In today's global economy and affordable vacation travel, it is increasingly important that visitors to another country and their physician be familiar with emerging infections, infections unique to a specific geographic region, and risks related to the process of travel. This is never more important than for patients with primary immunodeficiency disorders (PIDD). A recent review addressing common causes of fever in travelers provides important information for the general population Thwaites and Day (N Engl J Med 376:548-560, 2017). This review covers critical infectious and management concerns specifically related to travel for patients with PIDD. This review will discuss the context of the changing landscape of infections, highlight specific infections of concern, and profile distinct infection phenotypes in patients who are immune compromised. The organization of this review will address the environment driving emerging infections and several concerns unique to patients with PIDD. The first section addresses general considerations, the second section profiles specific infections organized according to mechanism of transmission, and the third section focuses on unique phenotypes and unique susceptibilities in patients with PIDDs. This review does not address most parasitic diseases. Reference tables provide easily accessible information on a broader range of infections than is described in the text.

Characterization of T and B cell repertoire diversity in patients with RAG deficiency.

Recombination-activating genes 1 and 2 (RAG1 and RAG2) play a critical role in T and B cell development by initiating the recombination process that controls the expression of T cell receptor (TCR) and immunoglobulin genes. Mutations in the RAG1 and RAG2 genes in humans cause a broad spectrum of phenotypes, including severe combined immunodeficiency (SCID) with lack of T and B cells, Omenn syndrome, leaky SCID, and combined immunodeficiency with granulomas or autoimmunity (CID-G/AI). Using next-generation sequencing, we analyzed the TCR and B cell receptor (BCR) repertoire in 12 patients with RAG mutations presenting with Omenn syndrome (n = 5), leaky SCID (n = 3), or CID-G/AI (n = 4). Restriction of repertoire diversity skewed usage of variable (V), diversity (D), and joining (J) segment genes, and abnormalities of CDR3 length distribution were progressively more prominent in patients with a more severe phenotype. Skewed usage of V, D, and J segment genes was present also within unique sequences, indicating a primary restriction of repertoire. Patients with Omenn syndrome had a high proportion of class-switched immunoglobulin heavy chain transcripts and increased somatic hypermutation rate, suggesting in vivo activation of these B cells. These data provide a framework to better understand the phenotypic heterogeneity of RAG deficiency.

BCG vaccination in patients with severe combined immunodeficiency: complications, risks, and vaccination policies.

BACKGROUND: Severe combined immunodeficiency (SCID) is a syndrome characterized by profound T-cell deficiency. BCG vaccine is contraindicated in patients with SCID. Because most countries encourage BCG vaccination at birth, a high percentage of patients with SCID are vaccinated before their immune defect is detected. OBJECTIVES: We sought to describe the complications and risks associated with BCG vaccination in patients with SCID. METHODS: An extensive standardized questionnaire evaluating complications, therapeutics, and outcomes regarding BCG vaccination in patients given a diagnosis of SCID was widely distributed. Summary statistics and association analysis was performed. RESULTS: Data on 349 BCG-vaccinated patients with SCID from 28 centers in 17 countries were analyzed. Fifty-one percent of the patients had BCG-associated complications, 34% disseminated and 17% localized (a 33,000- and 400-fold increase, respectively, over the general population). Patients receiving early vaccination (≤1 month) showed an increased prevalence of complications (P = .006) and death caused by BCG-associated complications (P < .0001). The odds of experiencing complications among patients with T-cell numbers of 250/µL or less at diagnosis was 2.1 times higher (95% CI, 1.4-3.4 times higher; P = .001) than among those with T-cell numbers of greater than 250/µL. BCG-associated complications were reported in 2 of 78 patients who received antimycobacterial therapy while asymptomatic, and no deaths caused by BCG-associated complications occurred in this group. In contrast, 46 BCG-associated deaths were reported among 160 patients treated with antimycobacterial therapy for a symptomatic BCG infection (P < .0001). CONCLUSIONS: BCG vaccine has a very high rate of complications in patients with SCID, which increase morbidity and mortality rates. Until safer and more efficient antituberculosis vaccines become available, delay in BCG vaccination should be considered to protect highly vulnerable populations from preventable complications.

A systematic analysis of recombination activity and genotype-phenotype correlation in human recombination-activating gene 1 deficiency.

BACKGROUND: The recombination-activating gene (RAG) 1/2 proteins play a critical role in the development of T and B cells by initiating the VDJ recombination process that leads to generation of a broad T-cell receptor (TCR) and B-cell receptor repertoire. Pathogenic mutations in the RAG1/2 genes result in various forms of primary immunodeficiency, ranging from T(-)B(-) severe combined immune deficiency to delayed-onset disease with granuloma formation, autoimmunity, or both. It is not clear what contributes to such heterogeneity of phenotypes. OBJECTIVE: We sought to investigate the molecular basis for phenotypic diversity presented in patients with various RAG1 mutations. METHODS: We have developed a flow cytometry-based assay that allows analysis of RAG recombination activity based on green fluorescent protein expression and have assessed the induction of the Ighc locus rearrangements in mouse Rag1(-/-) pro-B cells reconstituted with wild-type or mutant human RAG1 (hRAG1) using deep sequencing technology. RESULTS: Here we demonstrate correlation between defective recombination activity of hRAG1 mutant proteins and severity of the clinical and immunologic phenotype and provide insights on the molecular mechanisms accounting for such phenotypic diversity. CONCLUSIONS: Using a sensitive assay to measure the RAG1 activity level of 79 mutations in a physiologic setting, we demonstrate correlation between recombination activity of RAG1 mutants and the severity of clinical presentation and show that RAG1 mutants can induce specific abnormalities of the VDJ recombination process.

Clinical predictors of primary immunodeficiency diseases in children.

PURPOSE: To promote awareness of primary immunodeficiency (PID), the "10 warning signs" of PID and an immunodeficiency-related (IDR) score were developed. However, their efficiency in identifying PID cases was not sufficiently evaluated in clinical practice. The objective of this study was to test the validity of the 10 warning signs and IDR score in identifying PID among children with recurrent infections at a tertiary pediatric hospital in Egypt. METHODS: A retrospective analysis of the medical records of 204 patients was performed. Of these patients, 92 had defined PID diseases and 112 were considered non-PID cases because investigations were inconclusive. RESULTS: Demonstrating two warning signs and an IDR score of 6 led to sensitivities of 94 and 66%, respectively, and specificities of 64 and 75%, respectively, in identifying PID cases. The strongest predictor of PID was family history that, if combined with the need for intravenous antibiotics, recurrent deep-seated infections, and failure to thrive, could identify 81% of PID patients. A family history of PID, sibling death, and/or parental consanguinity would predict 92% of combined immunodeficiencies, 92% of phagocyte defects, 87% of well-identified immunodeficiency syndromes, and 84% of antibody deficiency if the need for intravenous antibiotics is considered in the latter. CONCLUSIONS: The 10 warning signs and IDR score do not aid in an early diagnosis of severe PID. Educational campaigns should target pediatricians aiming to increase PID awareness and to address family history of PID, parental consanguinity, and previous sibling death as key predictors of PID in communities with a high prevalence of consanguineous marriages.

Primary immunodeficiency diseases in Egyptian children: a single-center study.

INTRODUCTION: Sixty-four primary immunodeficiency patients were registered at the Pediatric Allergy and Immunology Department, Children's Hospital, Ain Shams University, Cairo, Egypt. DATA: Predominantly antibody deficiencies were the most common category (35.9%) followed by combined T- and B-cell immunodeficiencies (29.7%), other well defined immunodeficiency syndromes (18.7%), congenital defects of phagocyte number, function or both (12.5%), and diseases of immune dysregulation (3.1%). The most frequent disorder was common variable immunodeficiency (18.7%). The mean age at diagnosis was 29.9 months. The consanguinity rate was 62.5%. Recurrent severe infections were seen in all categories. Fifteen patients died (23.4%) from infections with the highest mortality for combined T- and B-cell immunodeficiencies (15.6%). CONCLUSIONS: Primary immunodeficiency disorders are not rare in Egyptian children. The observed frequency of combined T- and B-cell immunodeficiencies in our cohort is relatively higher than other countries. It is a prerequisite to establish a national registry of primary immunodeficiency in Egypt.