Immunology and Genetics Journal
Year:2020 | Volume:3 | Issue:3|Papers Count:6

Activated PI3 kinase delta syndrome (APDS) is a newly recognized primary immunodeficiency that was firstly discovered in 2013. APDS can be resulted from gain-of-function mutations in PI3Kδ catalytic p110δ (PIK3CD known as APDS1) and regulatory p85α (PIK3R1 known as APDS2). Patients with APDS syndrome mostly present some major manifestations such as lymphadenopathy and autoimmune diseases like cytopenia and Immune thrombocytopenic purpura (ITP). Distinguishing APDS from the other antibody deficiencies such as the common variable immunodeficiency (CVID) and hyper IgM disorders is very important to use appropriate and targeted treatment strategies. In this review article, we attempted to discuss the pathogenesis, cell abnormality, clinical manifestations, diagnosis, and treatment of APDS disorder.

Chronic granulomatous disease (CGD) is a relatively rare inborn error of immune system caused by some defects in the phagocyte nicotinamide adenine dinucleotide phosphate (NADPH) oxidase complex, which leads to the impaired production of reactive oxygen species (ROS) and ineffective function of phagocyte. Moreover, genetic defects of any one of proteinaceous components of NADPH oxidase complex results in CGD. The most common type of CGD (65-70%) is caused by X-linked mutations in the CYBB gene encoding gp91phox, followed by autosomal recessive mutations in the NCF1, NCF2, CYBA and NCF4 genes, which encode p47phox, p67phox, p22phox, and p40phox, respectively. In this regard, Dihydrorhodamine (DHR) 123 oxidation and nitroblue tetrazolium (NBT) tests are both used for the diagnosis of CGD that should be confirmed by genetic testing at first. CGD patients generally present with recurrent infections caused by uncommon pathogens such as aspergillus, staphylococcus aureus, burkholderia cepacia, serratia marcescens, Aspergillus species, and nocardia. They usually manifest with deep seated abscess formation, genitourinary and gastrointestinal granuloma development, autoimmunity, and malignancy. Apart from comprehensive treatment of acute infections, the management of CGD is performed based on reducing bacterial and fungal infections as well as minimizing the inflammatory symptoms. Also, antibiotics, anti-fungal, and IFN-γ are used for prophylaxis. Allogeneic hematopoietic stem cell transplantation from a human leucocyte antigen identical donor is currently considered as the only proven curative treatment for CGD. Accordingly, gene therapy is known as an alternative novel therapeutic approach in near future.

Background/objectives: The common variable immunodeficiency (CVID) is known as the most prevalent symptomatic primary immune deficiency (PID) diseases, which is characterized by lower antibody serum levels as well as several infectious and noninfectious manifestations. In this regard, Bronchiectasis is considered as a common respiratory complication and a vital challenge in CVID cases. This study aimed to evaluate the prevalence of bronchiectasis and investigate its association with other manifestations in CVID patients. Methods: A total of 297 patients diagnosed with CVID according to the relevant criteria were included in the current study. The query was performed to collect the participants’ demographic data, clinical manifestations, and laboratory findings. The analysis was performed between the two groups of the study including CVID patients with bronchiectasis and those without it. Results: Overall, the prevalence rate of bronchiectasis was calculated to be 28. 3%. Also, CVID patients with bronchiectasis had significant higher prevalence rates of respiratory manifestations, recurrent infections, otitis, clubbing, lymphoproliferative diseases, urinary tract infections, gastrointestinal diseases, dermatologic infections, allergy, and autoimmunity compared to the group including the patients without bronchiectasis. Notably, no significant differences were observed in antibodies serum levels between the patients with and without bronchiectasis. Moreover, CD19+ lymphocytes and CD8+ lymphocytes had significantly lower and higher percentages in CVID patients with bronchiectasis compared to those without it, respectively. Conclusion: The higher prevalence of bronchiectasis in CVID patients might be correlated with some other severe respiratory and off-respiratory clinical complications. Therefore, these manifestations should be precisely managed to impede a serious condition of bronchiectasis in CVID patients.

Background: Hyper IgM (HIGM) syndrome or immunoglobulin class-switch recombination deficiency (Ig-CSR) is a group of primary immunodeficiencies (PIDs) where B cells are unable to undergo the pro cess of immunoglobulin class-switching recombination (CSR), a process in which B-cells modify their DNA to switch from production of IgM to other immunoglobulins. Hence, the affected patients exhibit normal to high levels of serum IgM and low or absence of other immunoglobulin isotypes relative to mean values of age. Therefore, the present study was conducted to assess the demographic data, clinical manifes tation, and immunological findings in the sporadic and familial types of HIGM. Method: Demographic data, laboratory findings, and clinical presentations of 79 Iranian patients diagnosed with HIgM syndrome were collected. All the patients were classified into two different groups: sporadic and familial types of HIGM. Results: Male to female ratio was significantly higher in the familial group compared to the sporadic group so that, 94. 7% of the patients were male in the familial group, while only 70% of the sporadic patients were male (P=0. 032). It was also found that the familial group had a significantly higher consanguinity rate (P=0. 047) and a significantly lower delay of diagnosis compared to the sporadic group (P=0. 006). The lower respiratory infection (42%) followed by upper respiratory infection (26%) and diarrhea (15%) were the most frequent initial presentations. It was shown that diarrhea, as an initial presentation was about three times more common among the familial group (31. 6%) compared to the sporadic group (10%, P=0. 028). Otitis was also found to be more prevalent in the sporadic group (P=0. 042). Conclusion: Our findings could be explained by more careful screenings and more vigilant and informa tive parents in the families with another affected member.

Severe combined immunodeficiency (SCID) is one of the most serious and life-threatening forms of primary immunodeficiency disorders (PID). SCID patients manifest a large clinically heterogeneous group of monogenic disorders caused by a defect in human innate and adaptive immune response. It leads to an increased susceptibility to a variety of infections, sometimes with fatal outcomes. To date, more than 30 candidate genes and mutations in patients with SCID phenotype have been identified. We found a homozygous variation (c. 1454 A>G_ p. Asn485Ser) in the MALT1, identified by WES in an expired infant with SCID. The mutation in MALT1 is associated with the absence of T cell activation, which produces immature lymphocytes leading to SCID.

Biallelic lipopolysaccharide-responsive and beige-like anchor (LRBA) mutations could lead to an immune dysregulation disorder, labeled as LRBA deficiency. A wide spectrum of clinical manifesta tion was shown to be associated with recurrent infections, enteropathy, hypogammaglobulinemia, and autoimmune complications. Notably, LRBA interacts with cytotoxic T-lymphocyte-associated protein 4 (CTLA-4) by its recycling to the T-cell surface. Accordingly, LRBA deficiency abolishes CTLA4 protein expression. In this study, we presented a case with a homozygous mutation in the LRBA gene as well as a normal level of CTLA4 protein. In this regard, the immunologist assays of this patient revealed low immunoglobulin levels, CD4+ helper T cells, and CD19+ B cells.