Chronic Granulomatous Disease: a Cohort of 173 Patients-10-Years Single Center Experience from Egypt

PURPOSE

Chronic granulomatous disease (CGD) is an inherited primary immunodeficiency disorder of phagocytes, characterized by recurrent fungal and bacterial infections. Our aim is to describe the different clinical presentations, non-infectious auto-inflammatory features, types and sites of infections, and to estimate the mortality among our large cohort.

METHODS

This is a retrospective study conducted at the Pediatric Department of Cairo University Children's Hospital in Egypt, including cases with a confirmed CGD diagnosis.

RESULTS

One hundred seventy-three confirmed CGD patients were included. AR-CGD was diagnosed in 132 patients (76.3%) including 83 patients (48%) with p47phox defect, 44 patients (25.4%) with p22phox defect, and 5 patients (2.9%) with p67phox defect. XL-CGD was diagnosed in 25 patients (14.4%). The most common recorded clinical manifestations were deep-seated abscesses and pneumonia. Gram-negative bacteria and Aspergillus were the most frequently isolated species. Regarding the outcome, 36 patients (20.8%) were lost from follow-up. Among patients with known outcome, 94/137 patients (68.6%) are living, while 43/137 patients (31.4%) died.

CONCLUSION

AR-CGD is predominant in Egypt; CGD must always be ruled out in any patient presenting with typical or atypical mycobacterial or BCG-disease.

Cernunnos deficiency: Further delineation in 5 Egyptian patients

Cernunnos deficiency is a rare genetic disorder characterized by immunodeficiency, microcephaly, growth retardation, bird-like facies, sensitivity to ionizing radiation, few autoimmune manifestations, premature aging of hematopoietic stem cells at an early age, and occasional myeloproliferative disease. Herein we present five Egyptian Cernunnos patients from 3 different families. We describe the patients' clinical phenotypes, their immunological profile as well as genetic results. Sequence analysis revealed three different mutations in the NHEJ1 gene: a nonsense variant c.532C > T; p.(Arg178Ter), an intronic variant c.178-1G > A and a frameshift insertion variant c.233dup; p.(Asn78LysfsTer14). In conclusion, Cernunnos deficiency can have a wide range of clinical features. The characteristic immune profile including a decrease in recent thymic emigrants and naive T cells, markedly elevated memory T cells together with normal to high IgM, and a decrease in IgG and IgA. This immune profile is highly suggestive of Cernunnos deficiency in T-B-NK + SCID patients especially surviving for older ages.

Flow cytometry optimizing the diagnostic approach in inborn errors of immunity: experience from Egypt

Background

Human inborn errors of immunity (IEI) are a group of inherited genetic disorders of the immune system. IEI Patients suffer from severe repeated infections, autoimmunity, lymphadenopathy and/or increased susceptibility to malignancies. IEI are due to absence, disproportion, or loss of function of immune cells; mostly inherited in autosomal recessive manner, hence are more common in countries with high rate of consanguinity. Definite diagnosis of IEI is achieved by genetic analysis, however it is not always available. Aim: to report on different IEI categories and impact of expanding the use of flow cytometry (FCM) in diagnosis, categorization and follow up of IEI patients in a highly consanguineous population.

Methods

Retrospective chart review on different IEI categories diagnosed at the primary immunodeficiency center in Cairo University Specialized Pediatric hospital from 2011 to 2021 based on expanding the use of FCM.

Results

1510 IEI patients were diagnosed; 480 were diagnosed genetically with FMF, 11 with cystic fibrosis and 1019 patients were diagnosed with other IEI disorders. Phagocytic defects were the commonest (30%) followed by severe combined immunodeficiency (22%) and combined immunodeficiency (18.3%). FCM testing properly diagnosed and categorized 73% of the cases.

Conclusion

Using multi-color FCM to evaluate immune cells populations, subpopulations, functions, and intracellular proteins expression is proved a useful cost-effective method for screening, categorization and follow up of IEI patients. FCM can improve the diagnosis of IEI significantly when tests are properly targeted and well designed. This study presents a 10-year experience in diagnosis of IEI using FCM at a tertiary referral center in a setting of limited resources and yet high prevalence of IEI.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13223-022-00688-w.

Whole-exome sequencing of T- B+ severe combined immunodeficiency in Egyptian infants, JAK3 predominance and novel variants

Severe combined immunodeficiency (SCID) is fatal if not treated with immune reconstitution. In Egypt, T- B+ SCID accounts for 38·5% of SCID diagnoses. An accurate genetic diagnosis is essential for choosing appropriate treatment modalities and for offering genetic counseling to the patient's family. The objectives of this study were to describe the clinical, immunological and molecular characteristics of a cohort of twenty Egyptian patients with T- B+ SCID. The initial diagnosis (based on clinical features and flow cytometry) was followed by molecular investigation (whole-exome sequencing). All patients had the classic clinical picture for SCID, including failure to thrive (n = 20), oral candidiasis (n = 17), persistent diarrhea (n = 14), pneumonia (n = 13), napkin dermatitis (n = 10), skin rash (n = 7), otitis media (n = 3) and meningitis (n = 2). The onset of manifestations was at the age of 2·4 ± 1·6 months and diagnosis at the age of 6·7 ± ·5 months, giving a diagnostic delay of 4·3 months. JAK3 gene variants were most frequent (n = 12) with three novel variants identified, followed by IL2Rγ variants (n = 6) with two novel variants. IL7Rα and CD3ε variants were found once, with a novel variant each. T- B+ NK- SCID accounted for approximately 90% of the Egyptian patients with T- B+ SCID. Of these T- B+ NK- SCID cases, 60% were autosomal recessive syndromes caused by JAK3 mutations and 30% were X-linked syndromes. It might be useful to sequence the JAK3 gene (i.e. targeted Sanger sequencing) in all T- B+ SCID patients, especially after X-linked SCID has been ruled out. Hence, no more than 10% of T- B+ SCID patients might require next-generation for a molecular diagnosis.

Clinical Phenotypes and Immunological Characteristics of 18 Egyptian LRBA Deficiency Patients

LPS-responsive beige-like anchor (LRBA) deficiency is an autosomal recessive primary immunodeficiency disorder, OMIM (#614700). LRBA deficiency patients suffer from variable manifestations including recurrent infections, immune dysregulation, autoimmunity, cytopenias, and enteropathy. This study describes different clinical phenotypes and immunological characteristics of 18 LRBA deficiency patients diagnosed from Egypt. T and B lymphocyte subpopulations, LRBA, and cytotoxic T lymphocyte-associated protein 4 (CTLA4) expression were evaluated in resting and stimulated T cells using flow cytometry. Next-generation sequencing was used to identify mutations in the LRBA gene. LRBA deficiency patients had significantly lower B cells and increased percentage of memory T cells. CTLA4 levels were lower in LRBA-deficient T regulatory cells in comparison to healthy donors at resting conditions and significantly increased upon stimulation of T cells. We identified 11 novel mutations in LRBA gene ranging from large deletions to point mutations. Finally, we were able to differentiate LRBA-deficient patients from healthy control and common variable immunodeficiency patients using a simple flow cytometry test performed on whole blood and without need to prior stimulation. LRBA deficiency has heterogeneous phenotypes with poor phenotype-genotype correlation since the same mutation may manifest differently even within the same family. Low LRBA expression, low numbers of B cells, increased numbers of memory T cells, and defective CTLA4 expression (which increase to normal level upon T cell stimulation) are useful laboratory tests to establish the diagnosis of LRBA deficiency. Screening of the siblings of affected patients is very important as patients may be asymptomatic at the beginning of the disease course.

Role of Flow Cytometry in the Diagnosis of Chronic Granulomatous Disease: the Egyptian Experience

INTRODUCTION

Chronic granulomatous disease (CGD) is an inherited mutational defect in any of the NADPH oxidase complex, CYBB (gp91-phox), NCF1 (p47-phox), CYBA (p22-phox), NCF2 (p67-phox), or NCF4 (p40-phox) leading to inability of phagocytes to perform effective respiratory burst and thus diminished killing of bacteria and fungi. The identification of defective proteins aids in establishing a diagnosis prior to genetic analysis, which is rather labor-intensive, expensive, and time-consuming.

AIM

The present study aims at assessing the NADPH proteins by performing the intracellular staining with specific monoclonal antibodies and their assessment on flow cytometry. The use of flow cytometry is less laborious and faster to perform than western blot. It also confirms the diagnosis of CGD and detects the affected components allowing proper management of patients.

MATERIALS AND METHODS

Twenty-eight patients from 25 different kindred, clinically suspected as CGD were recruited in Egypt. Dihydrorhodamine test was performed to confirm the diagnosis of the patients. Intracellular staining of NADPH components using specific monoclonal antibodies was performed followed by flow cytometric analysis.

RESULTS

The present study revealed that the most common defective protein in our cohort is p22-phox, found in 13 patients (46.4 % of cases) followed by p47-phox in 8 patients (28.6 %), gp91-phox in 5 patients (17.9 %), and finally p67-phox in 2 patients (7.1 %).

CONCLUSION

In countries with limited resources and yet large number of CGD patients, the analysis of the defective proteins by flow cytometry is an optimum solution for confirming the diagnosis and is a step for targeted sequencing in families seeking prenatal diagnosis.

Mutations in Recombination Activating Gene 1 and 2 in patients with severe combined immunodeficiency disorders in Egypt

The Recombination Activating Genes (RAG) 1/2 are important for the development and function of T and B cells. Loss of RAG1/2 function results in severe combined immunodeficiency (SCID), which could lead to early death. We studied the prevalence of RAG1/2 mutations in ten SCID patients in Egypt. We identified two novel homozygous nonsense mutations in RAG1, a novel homozygous deletion, and a previously reported homozygous missense mutation from four patients, as well as two homozygous mutations in RAG2 from the same patient. Prenatal diagnosis performed in the mother of a patient with RAG1 deficiency determined that the fetus was heterozygous for the same mutation. This represents the first report on RAG1/2 mutations in SCID patients in Egypt. The early diagnosis dramatically affects the outcome of the disease by allowing bone marrow transplantation at an early age, and providing prenatal diagnosis and genetic counseling for families with a history of SCID.

The extended clinical phenotype of 64 patients with dedicator of cytokinesis 8 deficiency

BACKGROUND

Mutations in dedicator of cytokinesis 8 (DOCK8) cause a combined immunodeficiency (CID) also classified as autosomal recessive (AR) hyper-IgE syndrome (HIES). Recognizing patients with CID/HIES is of clinical importance because of the difference in prognosis and management.

OBJECTIVES

We sought to define the clinical features that distinguish DOCK8 deficiency from other forms of HIES and CIDs, study the mutational spectrum of DOCK8 deficiency, and report on the frequency of specific clinical findings.

METHODS

Eighty-two patients from 60 families with CID and the phenotype of AR-HIES with (64 patients) and without (18 patients) DOCK8 mutations were studied. Support vector machines were used to compare clinical data from 35 patients with DOCK8 deficiency with those from 10 patients with AR-HIES without a DOCK8 mutation and 64 patients with signal transducer and activator of transcription 3 (STAT3) mutations.

RESULTS

DOCK8-deficient patients had median IgE levels of 5201 IU, high eosinophil levels of usually at least 800/μL (92% of patients), and low IgM levels (62%). About 20% of patients were lymphopenic, mainly because of low CD4(+) and CD8(+) T-cell counts. Fewer than half of the patients tested produced normal specific antibody responses to recall antigens. Bacterial (84%), viral (78%), and fungal (70%) infections were frequently observed. Skin abscesses (60%) and allergies (73%) were common clinical problems. In contrast to STAT3 deficiency, there were few pneumatoceles, bone fractures, and teething problems. Mortality was high (34%). A combination of 5 clinical features was helpful in distinguishing patients with DOCK8 mutations from those with STAT3 mutations.

CONCLUSIONS

DOCK8 deficiency is likely in patients with severe viral infections, allergies, and/or low IgM levels who have a diagnosis of HIES plus hypereosinophilia and upper respiratory tract infections in the absence of parenchymal lung abnormalities, retained primary teeth, and minimal trauma fractures.