Characterization of B cell lymphoma in patients with Sjögren's syndrome and hepatitis C virus infection

Objective. To characterize the clinical and immunologic patterns of expression, response to therapy, and outcome of patients with Sjögren's syndrome (SS) and associated hepatitis C virus (HCV) infection who developed B cell lymphoma. Methods. Various international reference centers constituted a multicenter study group with the purpose of creating a registry of patients with SS-HCV who developed B cell lymphoma. A protocol form was used to record the main characteristics of SS, chronic HCV infection, and B cell lymphoma. Results. Twenty-five patients with SS-HCV with B cell lymphoma were included in the registry. There were 22 (88%) women and 3 (12%) men (mean age 55, 58, and 61 years at SS, HCV infection, and lymphoma diagnosis, respectively). The main extraglandular SS manifestations were cutaneous vasculitis in 15 (60%) patients and peripheral neuropathy in 12 (48%); the main immunologic features were positive rheumatoid factor (RF) in 24 (96%) and type II cryoglobulins in 20 (80%). The main histologic subtypes were mucosa-associated lymphoid tissue (MALT) lymphoma in 11 (44%) patients, diffuse large B cell lymphoma in 6 (24%), and follicular center cell lymphoma in 6 (24%). Fifteen (60%) patients had an extranodal primary location, most frequently in the parotid gland (5 patients), liver (4 patients), and stomach (4 patients). Twelve (52%) of 23 patients died after a median followup from the time of lymphoma diagnosis of 4 years, with lymphoma progression being the most frequent cause of death. Survival differed significantly between the main types of B cell lymphoma. Conclusion. Patients with SS-HCV and B cell lymphoma are clinically characterized by a high frequency of parotid enlargement and vasculitis, an immunologic pattern overwhelmingly dominated by the presence of RF and mixed type II cryoglobulins, a predominance of MALT lymphomas, and an elevated frequency of primary extranodal involvement in organs in which HCV replicates (exocrine glands, liver, and stomach).