Objective: To analyse the frequency of some extrahepatic manifestations of chronic hepatitis C virus (HCV) infection in northern European patients, including a postulated association between HCV and primary Sjögren's syndrome (SS).
Design: Cohort study.
Setting: Department of Medicine, Malmö University Hospital, Sweden.
Patients: Twenty-one patients with HCV infection and 53 with primary SS (according to the Copenhagen criteria).
Main outcome measures: Cryoglobulins were analysed in all patients, while patients with primary SS were investigated with regard to markers of HCV infection, and HCV patients with objective tests of SS (Schirmer-1 test, break-up time, van Bijsterveld score, sialometry, labial salivary gland biopsy) and antibodies against nuclear antigens, smooth muscle (SMA) and mitochondria (AMA). HCV antigens in small salivary glands from lower lip biopsies were detected by immunohistochemical analysis.
Results: Only one of the SS patients had detectable cryoprecipitates, while another was HCV-positive. None of the 21 HCV patients had cryoprecipitates. A total of 14/21 (67%) patients with HCV infection had at least one abnormal objective test suggestive of xerostomia or keratoconjunctivitis sicca, while eight (38%) had objective evidence of both eye and salivary gland involvement. HCV antigens were not detected in affected glands. Only two patients had clinical symptoms of SS, and two fulfilled the Copenhagen criteria for SS. None of the HCV-positive patients had detectable antibodies against SS-A, SS-B, RNP, Jo-1, PCNA or Scl-70, and the frequency of ANA/SMA/AMA was low.
Conclusions: While involvement of salivary and lacrimal glands was common in Swedish patients with HCV infection, cryoglobulinaemia was not observed. The pathogenetic mechanism responsible for glandular inflammation appears to be different from that in primary SS. HCV infection does not seem to be an aetiological factor for primary SS in this population. These observations suggest that viral, genetic or possibly environmental factors may be responsible for the reported high frequencies of systemic complications associated with chronic hepatitis C infection in southern Europe.