Are mannose-binding lectin gene 2 (MBL2) polymorphisms and MBL deficiency associated with infections?

Genetic profile and patient-reported outcomes in chronic obstructive pulmonary disease: A systematic review

BACKGROUND

Chronic Obstructive Pulmonary Disease (COPD) impacts differently on patients at similar grades, suggesting that factors other than lung function may influence patients' experience of the disease. Recent studies have found associations between genetic variations and patient-reported outcomes (PROs). Identifying these associations might be fundamental to predict the disease progression and develop tailored interventions. This systematic review aimed to identify the genetic variations associated with PROs in COPD.

METHODS AND FINDINGS

Databases were searched until July 2017 (PROSPERO: CRD42016041639) and additional searches were conducted scanning the reference list of the articles. Two independent reviewers assessed the quality of studies using the Q-Genie checklist. This instrument is composed of 11 questions, each subdivided in 7 options from 1 poor-7 excellent. Thirteen studies reporting 5 PROs in association with genes were reviewed. Studies were rated between "good quality" (n = 8) and "moderate" (n = 5). The most reported PRO was frequency of exacerbations (n = 7/13), which was mainly associated with MBL2 gene variants. Other PRO's were health-related quality of life (HRQOL) (n = 4/13), depressive symptoms (n = 1/13), exacerbation severity (n = 1/13) and breathlessness, cough and sputum (n = 1/13), which were commonly associated with other genetic variants.

CONCLUSIONS

Although a limited number of PRO's have been related to genetic variations, findings suggest that there is a significant association between specific gene variants and the number/severity of exacerbations, depressive symptoms and HRQOL. Further research is needed to confirm these findings and assess the genetic influence on other dimensions of patients' lives, since it may enhance our understanding and management of COPD.

Association of the Risk of Dental Caries and Polymorphism of MBL2 rs11003125 Gene in Iranian Adults

This case-control study aimed to investigate the effect of rs11003125 in dental caries. For this purpose, a total number of 404 individuals - from Fars Province in Iran - were studied. The technique of this research was the tetra-primer amplification-refractory mutation system (ARMS)-PCR. Dental caries prevalence among the 404 individuals was assessed by counting the number of decayed, missing, and filled teeth. In this research, individuals were divided into two groups: cases (n = 238) and controls (n = 166), and the peripheral blood samples were used to extract the genomic DNA. For genotyping of DNA, the tetra-primer ARMS-PCR method was conducted using specific primer pairs. While examining MBL2 rs11003125 polymorphism, we found significant differences in the genotype frequencies between the case and the control group. The pooled estimates indicated that the GG and GC genotypes of MBL2 rs11003125 polymorphism significantly increased, and therefore caries risk (OR = 2.40, 95% CI = 1.31-4.40, p = 0.004) under the dominant model. These findings suggested that polymorphism in MBL2 gene was associated with dental caries in Iranian adults. Further verification is needed with more ethnic groups and larger sample sizes to determine whether rs11003125 polymorphism is related to dental caries in other regions or not.

Evaluation of the T helper 17 cell specific genes and the innate lymphoid cells counts in the peripheral blood of patients with the common variable immunodeficiency

BACKGROUND

Common variable immunodeficiency (CVID) is characterized by a deficiency in the immune system with a heterogeneous collection of disorders resulting in antibody deficiency and recurrent infections. T helper 17 (Th17) cells promote B-cell survival and synergize with the B-cell activating factor to induce their differentiation into the plasma cells. A sub-population of innate lymphoid cells (ILCs) also produces interleukin 17 (IL-17). This study aimed to measure the Th17 specific genes and ILCs counts in the CVID patients in comparison with control subjects.

MATERIALS AND METHODS

Total messenger ribonucleic acid (mRNA) was extracted from the whole blood samples of 10 CVID patients and 10 healthy individuals. IL-17, retinoic acid receptor-related orphan receptor C2 (RORC2), IL-23R, and IL-9 gene expression were measured using the quantitative reverse transcriptase-polymerase chain reaction. Count of lineage negative/CD127(+)/CD90(+) ILCs in the blood samples was performed by the flow cytometry method.

RESULTS

The transcript levels of IL-17 and RORC2 in CVID patients was strongly lower than control subjects (P = 0.049 and P = 0.046, respectively), but slight reduction in the IL-23R expression (P = 0.252) have seen in the CVID patients. Accordingly, the number of ILCs decreased significantly (P = 0.04). Interestingly, IL-9 mRNA level was more significantly in the CVID patients (P = 0.001).

CONCLUSION

The results presented in this study show that the Th17 cell specific genes expression (as the determiner Th17 cells) and ILCs (another lymphoid source of IL-17) are decreased in patients with CVID and this could be an explanation for the defect of their humoral immune response. In addition, elevation of the IL-9 gene expression may shed a new light into the way toward the understanding of the mechanism of autoimmunity in the CVID patients.

Genetic defects and the role of helper T-cells in the pathogenesis of common variable immunodeficiency

Common variable immunodeficfiiency (CVID) is a primary immunodeficiency syndrome representing a heterogeneous set of disorders resulting mostly in antibody deficiency and recurrent infections. However, inflammatory and autoimmune disorders and some kinds of malignancies are frequently reported as a part of the syndrome. Although it is one of the most widespread primary immunodeficiency, only recently some genetic defects in CVID have been identified. Mutations have been detected in inducible T-cell costimulator (ICOS), transmembrane activator and calcium modulator and cyclophilin ligand interactor (TACI), B-cell activating factor-receptor (BAFF-R), B-cell receptor complex (CD19, CD21 and CD81) and CD20. On the other hand, recent studies have shown a decrease in T-helper-17 cells frequency and their characteristic cytokines in CVID patients and this emphasis on the vital role of the T-cells in immunopathogenesis of the CVID. Furthermore, in the context of autoimmune diseases accompanying CVID, interleukin 9 has recently attracted a plenty of considerations. However, the list of defects is expanding as exact immunologic pathways and genetic disorders in CVID are not yet defined. In this review, we have a special focus on the immunopathogenesis of CVID, recent advances in understanding the underlying etiology and genetics for patients.