PD1.5 variant on PDCD1 gene, regulator of T lymphocyte activity, influences non-muscle-invasive bladder cancer risk

Since failure in recognition of abnormal cells by the immune system has an important role in bladder cancer development and progression, this study aimed to evaluate whether PD1 (c.627+252C>T) and PD1.5 (c.804C>T) single-nucleotide variants (SNVs) in PDCD1 gene, enrolled in modulation of T lymphocyte activity, influence risk, clinicopathological aspects, and outcome of non-muscle-invasive bladder cancer (NMIBC) patients.

DNA genotyping by real-time polymerase chain reaction was offered to 160 non muscle invasive bladder cancer (NMIBC) patients and 250 controls. One hundred and twenty-seven patients treated with bladder transurethral resection and intravesical bacillus Calmette-Guérin were enrolled in survival analyses.

Individuals with PD1.5 CC genotype had 2.3-fold increased risk of developing NMIBC. Similar genotype and haplotype frequencies were seen in patients stratified by clinicopathological aspects. Patients with T allele, CT or TT plus CT or TT genotype and TT haplotype of PD1 and PD1.5 SNVs had up to 4.0-times greater chances of presenting NMIBC relapse and death by any cause than the remaining patients, but analysis of NMIBC specific survival was not possible in study due to the small number of patients evolving to death during follow up.

Our data presented for the first time, preliminary evidence that inherited abnormality in regulation of T lymphocyte activity alters NMIBC risk.