Expression of apoptosis-associated protein RCAS1 in macrophages of histiocytic necrotizing lymphadenitis

Co-occurrence of Kikuchi-Fujimoto's disease and Still's disease: case report and review of previously reported cases

Kikuchi-Fujimoto's disease (KFD) and adult-onset Still's disease (AOSD) are rare inflammatory conditions with some overlapping features. We encountered a 22-year-old male patient who presented with daily fevers, neck discomfort, and sore throat and subsequently developed rash, arthritis, and cervical lymphadenopathy. Biopsy of the skin rash was consistent with KFD skin involvement. Given that the patient also met criteria for AOSD, a final diagnosis of KFD/AOSD co-occurrence was made. Anti-IL-1β therapy with anakinra resulted in rapid resolution of all symptoms. A literature search identified eight more cases of KFD/AOSD. Fever, rash, arthritis, and lymphadenopathy were present in all patients. No case report demonstrated an association of rash eruption clearly associated with fever spikes. Duration of symptoms ranged from 3 weeks to 10 years. Seven patients had leukocytosis, six had anemia, and five demonstrated elevated ferritin and/or decreased glycosylated ferritin. Seven patients had elevated erythrocyte sedimentation rate (ESR), and seven had transaminitis. Eight of nine patients had no evidence of infectious disease. Autoantibodies were absent from all patients. KFD and AOSD are very rare diseases, yet they may overlap. The two conditions not only share several clinical and laboratory characteristics but also differ in characteristic ways. Given the rapid response observed with anakinra in the index patient, IL-1β likely plays a role in both diseases.

Significance of RCAS1 antigen in hepatocellular, cholangiocellular and pancreatic carcinomas

Since receptor-binding cancer antigen expressed on SiSo cells (RCAS1) was first reported as a tumor-associated antigen of gynecologic cancer, its function and practical value as a tumor marker have been investigated in various types of carcinomas. Basic research has indicated that RCAS1 expression in cancer cells contributes to the evasion from immune surveillance and progression of carcinomas. The clinical significance of RCAS1 expression in hepatobiliary and pancreatic carcinomas has also been investigated. In this review, we summarize the clinical application of RCAS1 antigen in hepatic and pancreaticobiliary diseases. We present new data and review current knowledge about the potential of RCAS1 as a tumor marker and the relationship between RCAS1 expression and clinicopathologic parameters. We found that the clinical function of RCAS1 appeared to differ according to the type of carcinoma. In hepatocellular carcinoma, the clinical significance of histological RCAS1 expression was controversial and that of serum RCAS1 levels showed little clinical value. In pancreaticobiliary cancers, high RCAS1 expression in tissue samples was an unfavorable independent prognostic factor. Serum RCAS1 was a superior tumor marker reflecting the disease activity in biliary carcinoma. In pancreatic cancer, serum RCAS1 levels were less useful than in biliary carcinoma but may be available for genetically CA19-9-negative patients and for CA19-9-non-producing cancer. This review also offers suggestions for future studies.