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Variant not associated with CLL, AIHA, or ITP in certain patients


 

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DUBROVNIK, CROATIA—New research suggests there is no association between the PTPN22 R620W polymorphism and chronic lymphocytic leukemia (CLL) or autoimmune hematologic disorders in patients from the Republic of Macedonia.

Past studies have shown an association between the PTPN22 R620W variant and both CLL1 and autoimmune diseases2 in patients from Northwest Europe.

However, a study of Macedonian patients suggests there is no association between the variant and CLL, autoimmune hemolytic anemia (AIHA), or idiopathic thrombocytopenic purpura (ITP) for patients from Southeast Europe.

Irina Panovska-Stavridis, PhD, of Ss. Cyril and Methodius University in Skopje, Republic of Macedonia, and her colleagues presented this finding at Leukemia and Lymphoma: Europe and the USA, Linking Knowledge and Practice.

“A lot of data from the literature suggests [the PTPN22 R620W variant ] has a role in developing multiple immune diseases, but it is validated just in patients from Northwest Europe,” Dr. Panovska-Stavridis noted.

Therefore, she and her colleagues decided to assess the frequency of the PTPN22 R620W variant (C1858T, rs2476601) in individuals from Southeast Europe, particularly the Republic of Macedonia.

The researchers evaluated 320 patients—168 with CLL, 66 with AIHA, and 86 with ITP—and 182 age- and sex-matched control subjects with no history of malignant or autoimmune disease.

The team found a similar frequency of the minor T allele and genotype distribution in control subjects and patients.

CLL AIHA ITP Controls
Minor T allele 0.107 0.067 0.036 0.05
CC genotype 0.809 0.166 0.023 0.901
CT genotype 0.9 0.067 0.033 0.099
TT genotype 0.928 0.072 0 0

Dr. Panovska-Stavridis said these results suggest the PTPN22 R620W variant is not a risk factor for the development of CLL, AIHA, or ITP in patients from Southeast Europe.

She also said the results suggest the influence of the variant on lymphocytic homeostasis is affected by certain genetic and environmental factors, and the development of CLL and autoimmune diseases is influenced by race/ethnicity-based variations in the germline composition of the IGHV locus in correlation with environmental factors.

Dr. Panovska-Stavridis did not declare any conflicts of interest.

1. Hebbring S et al. Blood. 2013 121:237-238; doi: https://doi.org/10.1182/blood-2012-08-450221

2. Burb GL et al. FEBS Lett. 2011 Dec 1;585(23):3689-98. doi: 10.1016/j.febslet.2011.04.032

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