[Increase of CA 19.9 in dysimmune inflammatory rheumatism. Apropos of 6 cases]

CA 19.9 is a marker for several cancers, including ductal adenocarcinomas of the pancreas. CA 19.9 elevation is rarely found in patients without benign or malignant digestive system disease. We studied serum CA 19.9 levels in patients with a variety of inflammatory joint diseases, including rheumatoid arthritis (n = 20), lupus, Sjögren's syndrome or U1RNP-associated connective tissue syndrome (Sharp's syndrome) (n = 11), dermatopolymyositis (n = 8), and giant cell arteritis or polymyalgia rheumatica (n = 8). The mean CA 19.9 level in each of these groups was not significantly different from the value seen in a group of patients with osteoporosis. Six patients had persistent marked elevation in serum CA 19.9 levels. Two had Sjögren's syndrome, two had Sharp's syndrome and two had dermatopolymyositis. None of these six patients had evidence of tumoral disease despite a follow-up of several years. Likely explanations for the CA 19.9 elevation were chronic pancreatitis in one case and lung disease in the other five. In patients with lung involvement due to inflammatory joint disease, CA 19.9 elevation may indicate severe disease and may be of use for monitoring the lung condition.