title: Polymorphism of FCGR3A gene in sarcoidosis.
abstract: We showed increased level of immune complexes (ICs) with mycobacterial heat shock proteins (Mtb-hsp) and increased expression of receptors for Fc fragment of immunoglobulin G (FcγR) I-III on blood monocytes with their increased phagocytic activity, responsible for clearance of these ICs in sarcoidosis (SA). Since FcγRIIIa is the most crucial in this process, we genotyped 77 SA patients and 143 healthy controls with polymerase chain reaction for V158F polymorphism of FCGR3A gene, encoding FcγRIIIa. We revealed significantly higher percentage of 158F and 158FF and lower of 158FV variants in Stage I of SA versus controls. Conversely, in Stage II of SA, we found increase in 158VV homozygotes versus controls. We also showed significant increase of 158F and 158FF variants in Stage I vs II and of 158V in Stage II vs I. Therefore, in Stage I, 158F allele may cause decreased FcγRIIIa affinity and clearance of ICs, whereas in Stage II, 158V allele may cause effective FcγRIIIa affinity to ICs with e.g. mycobacteria, their phagocytosis, Mtb-hsp secretion with ICs formation, Mtb-hsp epitope spread and subsequent immune reaction. Thus, V158F polymorphism of FCGR3A may explain the immunocomplexemia in our patients and might serve as prognostic marker of clinical course of sarcoidosis.
authors: Department of Pneumology, Medical University of Gdansk, Debinki 7 St, 80-211 Gdansk, Poland. Electronic address: ma.smig@gumed.edu.pl.
authors: Marlena J
authors: MJ
authors: Typiak
authors: Department of Forensic Medicine, Medical University of Gdansk, Debowa 23 St, 80-204 Gdansk, Poland. Electronic address: k.rebala@gumed.edu.pl.
authors: Krzysztof
authors: K
authors: Rębała
authors: Non invasive Cardiac Diagnostic Department, Medical University of Gdansk, Mariana Smoluchowskiego 17 St, 80-214 Gdansk, Poland. Electronic address: mdudziak@gumed.edu.pl.
authors: Maria
authors: M
authors: Dudziak
authors: Department of Pneumology, Medical University of Gdansk, Debinki 7 St, 80-211 Gdansk, Poland. Electronic address: aduban@gumed.edu.pl.
authors: Anna
authors: A
authors: Dubaniewicz
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000483:Alleles; D016022:Case-Control Studies; D005260:Female; D005787:Gene Frequency; D005838:Genotype; D006801:Humans; D008297:Male; D008875:Middle Aged; D016017:Odds Ratio; D011110:Polymorphism, Genetic; D017452:Receptors, IgG / Q000235:genetics*; D012507:Sarcoidosis / Q000235:genetics* / Q000276:immunology / Q000473:pathology; D055815:Young Adult
chemical_list: C496124:FCGR3A protein, human; D017452:Receptors, IgG