Background Intravesical instillation of BCG is used as an effective immunotherapy of bladder cancer. However it may have, as adverse event, a reactive arthritis (ReA) and the incidence are known as about 0.5 to 1%.
Objectives To evaluate clinical characteristics and incidence of Japanese patients with ReA induced by intravesical BCG therapy (iBCG) for bladder cancer.
Methods The clinical symptoms, laboratory, and imaging findings of Japanese patients who received iBCG (n=405 (134 and 271 in Kochi University Hospital (KUH) and Kurashiki Medical Center (KMC), respectively)) for bladder cancer from March 1997 to October 2012 were retrospectively assessed. Especially, the patients with ReA and conjunctivitis/uveitis were examined. All data are presented as mean ± SD.
Results Of the patients received iBCG (age 71±10 and 69±11; male/female 95/39 and 215/56 in KUH and KMC, respectively), 40 (30%) and 35 (13%), 41 (31%) and 48 (18%), and 59 (44%) and 73 (27%) in KUH and KMC presented fever, hematuria and painful urination, respectively. ReA was revealed in 3/134 (2.2%) and 3/271 (1.1%), uveitis in 3/134 (2.2%) and 1/271 (0.4%), and conjunctivitis in 12/134 (8.9%) and 14/271 (5.2%) in KUH and KMC, respectively. As the total evaluation, ReA was revealed in 6/405 (1.5%). Moreover, most patients with ReA also had hepatic dysfuntion. All ReA were developed after 3-times of iBCG. Clinical, ultrasound and FDG-PET/CT findings of ReA induced by iBCG showed asymmetric polyarthritis/polyenthesitis pattern in shoulder, sternoclavicular joints, spinous process, sacroiliac joints, ischial tuberosity, hip, knee and ankle. Laboratory examinations showed high CRP (>10mg/dl) and 33% HLA-B27 positivity (in 1 of 3 cases). All ReA patients were improved by treatments with prednisolone and isoniazid.
Conclusions The incidence of ReA induced by iBCG in Japanese population was 1.5% and it might be almost equal or more than the incidence, 0.5 to 1%, in the Western countries from previous reports. Positive HLA-B27 was revealed in 33% of ReA patients as background in our study, suggesting lower frequency than 51 to 55% in the Western countries. Therefore, besides HLA phenotype, a cross reaction between a mycobacterium epitope and an antigen of joint cartilage might be suggested in the pathogenesis of ReA induced by iBCG in Japan.
Acknowledgements No funding support
Disclosure of Interest : None declared