MyMedR

Displaying all 6 publications

Abstract:

Sort:

FcgammaRIIa polymorphism in systemic lupus erythematosus

Tan SY

Kidney Blood Press Res, 2000;23(2):138-42.
PMID: 10765117 DOI: 10.1159/000025967

FcgammaRIIs are the most widely distributed of the Fcgamma receptor family and play an important role in the clearance of immune complexes. Evidence that the FcgammaRIIa-R131 allotype is less able to process and clear immune complexes effectively suggests that this may be a disease susceptibility factor for systemic lupus erythematosus (SLE). Data from studies published thus far do not agree on the potential role of FcgammaRIIa polymorphism in the genetics of SLE. Most studies in fact show no evidence for any correlation between polymorphism of FcgammaRIIa and risk for SLE. However, it remains to be determined whether FcgammaRIIa polymorphism may play a critical role in certain groups of patients, especially in those of differing ethnic background. Polymorphism of FcgammaRIIa may also be important in determining disease phenotype, and identification of this influence may have important implications in patient care and in identifying patients for more aggressive therapy.

Matched MeSH terms: Receptors, IgG/genetics*
Fulltext Messenger RNA of FCGR3A and FCGR3B Genes as Monitoring Markers of Clear Cell Renal Adenocarcinoma (a Pilot Study)

Alyasova AV, Amoev ZV, Shkola OO, Novikov DV, Selivanova SG, Novikov VV

Sovrem Tekhnologii Med, 2022;14(3):22-26.
PMID: 37064811 DOI: 10.17691/stm2022.14.3.03

The aim of the study was to assess the capabilities of mRNA genes encoding CD16a (FCGR3A) and CD16b (FCGR3B) in tumor samples from patients with renal cancer, and characterize the tumor process in relation to clinical and morphological factors.
MATERIALS AND METHODS: We used 125 tumor samples from patients with a histologically confirmed diagnosis of renal cancer T1-4N0-1M0-1. A method described by Chomczynski and Sacchi was used to isolate nucleic acids. The mRNA levels were determined using a reverse transcription polymerase chain reaction and calculated according to ΔΔCt formula, taking into account the reaction efficiency.
RESULTS: mRNA of the FCGR3A gene was detected in all tumor tissue samples under study; in contrast, mRNA of the FCGR3B gene was found only in 92.0% (115/125) of cases. In tumors classified as pT1, the mRNA content of the FCGR3A gene was significantly lower than that in tumor samples of pT3 size. There was the significant increase in the mRNA content of both genes with an increase in tumor grade, as well as in the cases with distant metastases. The presence of a tumor thrombus in the inferior vena cava system was accompanied by a significant increase in the mRNA content of the FCGR3A gene.
CONCLUSION: In tumor tissue samples from patients with clear cell renal cancer, the predominant production of the FCGR3A mRNA was observed in comparison with the FCGR3B mRNA. The revealed relationship of an increased amount of the FCGR3A mRNA and, in some cases, the FCGR3B mRNA with a number of clinical and morphological factors enables to consider the mRNA level of the genes as new monitoring biomarkers.

Matched MeSH terms: Receptors, IgG/genetics
Fulltext A comparison of assays for accurate copy number measurement of the low-affinity Fc gamma receptor genes FCGR3A and FCGR3B

Haridan US, Mokhtar U, Machado LR, Abdul Aziz AT, Shueb RH, Zaid M, et al.

PLoS One, 2015;10(1):e0116791.
PMID: 25594501 DOI: 10.1371/journal.pone.0116791

The FCGR3 locus encoding the low affinity activating receptor FcγRIII, plays a vital role in immunity triggered by cellular effector and regulatory functions. Copy number of the genes FCGR3A and FCGR3B has previously been reported to affect susceptibility to several autoimmune diseases and chronic inflammatory conditions. However, such genetic association studies often yield inconsistent results; hence require assays that are robust with low error rate. We investigated the accuracy and efficiency in estimating FCGR3 CNV by comparing Sequenom MassARRAY and paralogue ratio test-restriction enzyme digest variant ratio (PRT-REDVR). In addition, since many genetic association studies of FCGR3B CNV were carried out using real-time quantitative PCR, we have also included the evaluation of that method's performance in estimating the multi-allelic CNV of FCGR3B. The qPCR assay exhibited a considerably broader distribution of signal intensity, potentially introducing error in estimation of copy number and higher false positive rates. Both Sequenom and PRT-REDVR showed lesser systematic bias, but Sequenom skewed towards copy number normal (CN = 2). The discrepancy between Sequenom and PRT-REDVR might be attributed either to batch effects noise in individual measurements. Our study suggests that PRT-REDVR is more robust and accurate in genotyping the CNV of FCGR3, but highlights the needs of multiple independent assays for extensive validation when performing a genetic association study with multi-allelic CNVs.

Matched MeSH terms: Receptors, IgG/genetics*
Fc gamma receptor IIIB-NA gene frequencies in patients with systemic lupus erythematosus and healthy individuals of Malay and Chinese ethnicity

Yap SN, Phipps ME, Manivasagar M, Bosco JJ

Immunol Lett, 1999 Jun 01;68(2-3):295-300.
PMID: 10424435

The neutrophil antigen (NA)1 and 2 is coded by two recognized allelic forms of Fc gamma receptor IIIB (FcgammaRIIIB). FcgammaRIIIb is a low affinity receptor and preferentially removes immune complexes from the circulation. Systemic lupus erythematosus (SLE) is an autoimmune and polygenic disorder characterized by accumulation of autoimmune complexes. The majority of SLE patients in our medical center are of Chinese ethnicity, followed by Malay and Indian. Recently, studies have focussed on the Fc receptors in different ethnic groups and their relation to SLE. We chose to study the gene distribution of this receptor in the Chinese and Malays population in Malaysia. We designed a polymerase chain reaction allele specific primers (PCR-ASP) method to distinguish the two allelic forms. Genomic DNA was isolated from the peripheral blood of 183 Chinese and 55 Malays SLE patients as well as 100 Chinese and 50 Malays healthy controls. Genotyping of Chinese SLE patients revealed that the gene frequencies for FcgammaRIIIB-NA1 and FcgammaRIIIB-NA2 were 0.648 and 0.347, while in the ethnically matched healthy controls they were 0.68 and 0.32, respectively. One out of the 183 Chinese SLE patients was identified as a NA-null due to the absence of PCR product for both alleles. The FcgammaRIIIB-NA1 and FcgammaRIIIB-NA2 allele frequencies for both the Malays SLE and healthy controls were 0.62 and 0.38.

Matched MeSH terms: Receptors, IgG/genetics*
Fulltext Genetic risk factors of systemic lupus erythematosus in the Malaysian population: a minireview

Chai HC, Phipps ME, Chua KH

Clin. Dev. Immunol., 2012;2012:963730.
PMID: 21941582 DOI: 10.1155/2012/963730

SLE is an autoimmune disease that is not uncommon in Malaysia. In contrast to Malays and Indians, the Chinese seem to be most affected. SLE is characterized by deficiency of body's immune response that leads to production of autoantibodies and failure of immune complex clearance. This minireview attempts to summarize the association of several candidate genes with risk for SLE in the Malaysian population and discuss the genetic heterogeneity that exists locally in Asians and in comparison with SLE in Caucasians. Several groups of researchers have been actively investigating genes that are associated with SLE susceptibility in the Malaysian population by screening possible reported candidate genes across the SLE patients and healthy controls. These candidate genes include MHC genes and genes encoding complement components, TNF, FcγR, T-cell receptors, and interleukins. However, most of the polymorphisms investigated in these genes did not show significant associations with susceptibility to SLE in the Malaysian scenario, except for those occurring in MHC genes and genes coding for TNF-α, IL-1β, IL-1RN, and IL-6.

Matched MeSH terms: Receptors, IgG/genetics
Human Fc gamma receptor IIA (FcgammaRIIA) genotyping and association with systemic lupus erythematosus (SLE) in Chinese and Malays in Malaysia

Yap SN, Phipps ME, Manivasagar M, Tan SY, Bosco JJ

Lupus, 1999;8(4):305-10.
PMID: 10413210 DOI: 10.1191/096120399678847876

SLE is an autoimmune and polygenic disorder characterized by an accumulation and deposition of immune complexes. Several studies have indicated differential impact of FcgammaR polymorphism genotypes in different ethnic groups studied. The Fc receptor for IgG class IIA gene (FcgammaRIIA) occurs in two allelic forms. The allele FcgammaRIIA-H131 encodes a receptor with a histidine at the 131 amino acid position; the other allele FcgammaRIIA-R131 encodes an arginine. This polymorphism is believed to determine the affinity of the receptor for hIgG2 in immune complexes. FcgammaRIIA-H131 has a higher capacity for hIgG2 compared to FcgammaRIIA-R131 as measured by in vitro studies of insoluble immune complex clearance. We have investigated the polymorphism for FcgammaRIIA using a novel polymerase chain reaction-allele specific primer (PCR-ASP) method designed specifically to distinguish the two allelic forms. Our studies were based on 175 Chinese and 50 Malays SLE patients as well as 108 and 50 ethnically matched healthy controls for the respective groups. Analysis of the data (chi2 test with Yates correction factors and odds ratios) revealed that there were no significant differences between SLE patients and controls. We have not found evidence of a protective effect conferred by FcgammaRIIA-H131 in the ethnic groups studied.

Matched MeSH terms: Receptors, IgG/genetics*