Geeta Katwa M.D.              Univ. of Missouri--Columbia
Episodic polyarthritis with high-titer rheumatoid factor: 
pseudo-rheumatoid arthritis associated with hepatitis C and cryoglobulinemia  
         
 

A 37-year old construction worker had a past history of thermal injury with cold exposure in 1984, followed by purple discoloration of the fingers. In August 1998, he started to have episodic disabling pain in the shoulders, wrists, hands, and feet. Pain lasted for periods of 24 hours and subsided spontaneously with or without NSAIDs. Some episodes were associated with swelling of the right hand and the right foot. He presented to our hospital in February, 1999 with diffuse swelling of the right hand. A radiograph showed only soft tissue swelling. One month later the patient was re-evaluated. He complained of painful shoulders. Review of systems was negative for signs and symptoms of lupus, and for tick bite, morning stiffness, fatigue, conjunctivitis, urethritis, and diarrhea. Examination revealed purple discoloration of the fingers, widespread livedo reticularis, and remarkable limitation of shoulder range of motion. The patient was married and heterosexual. He denied extramarital sex, IV drug use, and blood transfusions. Laboratory investigation revealed very high rheumatoid factor (106 IU/ml; N=O-30) and a negative FANA test. The evaluation for purple fingers included testing for cryoglobulins and hepatitis. This patient had negative tests for hepatitis A and B. However, he had a positive test for anti-hepatitis C and > 1,000,000 HVC RNA copies/ml on quantitative PCR testing. Cryoglobulins were positive (1mm), and SGOT was minimally elevated (59 U/L; N=15-46). The combination of livedo reticularis and arthritis in this hepatitis C-positive patient led to the diagnosis of hepatitis C-associated arthritis, rather than rheumatoid arthritis. Inflammatory arthritis involving the shoulders, knees, wrists, hands, and hips has been described in 2 individuals with similar findings (J Am Acad Derm 37:659, 1997; Neth J Med 51:225, 1997). The high titer rheumatoid factor in our case is thought to result from the cryoglobulin, produced by virus stimulation of clonal expansion of B-cells. The cold-precipitable protein in hepatitis C-infected patients is typically mixed and has rheumatoid factor activity. He as been referred to a hepatologist for liver biopsy and further management. It is expected that interferon treatment will control his disease, including the skin lesions and arthritis.