LOW FREQUENCY OF CLONAL B CELL EXPANSIONS IN PATIENTS WITH IDIOPATHIC THROMBOCYTOPENIC PURPURA
Journal
Македонски медицински преглед = Macedonian Medical Review
Date Issued
2021-01-01
Author(s)
Efremov D
Abstract
Idiopathic thrombocytopenic purpura (ITP) is an autoimmune disorder characterized by an increased platelet destruction caused by autoantibodies directed against platelet membrane glycoproteins (GP), most commonly against GPIb/IX, GPIIb/IIIa and GPIa/IIa. In a few recent studies it has been reported that these antibodies frequently have a restricted light chain phenotype, supporting a clonal origin. In this study we wanted to explore the hypothesis of clonal B cell expansions in chronic ITP. We investigated 40 patients (28 women and 12 men) with chronic ITP for clonal B cell expansions using sensitive RT-PCR technique for analysing Ig-gene rearrangements. RNA was isolated from peripheral blood mononuclear cells separated on a Ficoll gradient. The RNA was converted into cDNA and then amplified using FW3 and IgM or IgG specific oligonucleotides to investigate the clonality of B-cells expressing the respective Ig isotype. The PCR fragments were analyzed on sequencing polyacrylamide gels or with an ABI prism 310 DNA analyser. We detected a monoclonal B cell population in only 1 patient and polyclonal rearrangement with one prominent band in 3 patients in the analysis of IgG heavy chain mRNA. The pattern of IgM heavy chain gene rearrangements was polyclonal in all cases. Our study indicates that clonal B-cell expansions are rare in patients with ITP. Most probably, the clonal B-cell expansion responsible for the production of autoantibodies in ITP, if present, is below the detection limit.
File(s)![Thumbnail Image]()
Loading...
Name
MMP202175(1).pdf
Size
4.01 MB
Format
Adobe PDF
Checksum
(MD5):668839acae420fc3da311e6dc700b4e3