Rheumatoid Factor and Disease Activity Are Independent Predictors of Lymphoma in Primary Sjögren's Syndrome.

OBJECTIVE: To define parameters predictive of lymphoma development in patients with primary Sjögren's syndrome (SS). METHODS: A multicenter case-control survey was performed to identify predictors of lymphoma. Cases were patients who developed lymphoma after diagnosis of primary SS and were mainly recruited through the Club Rhumatismes et Inflammation network. For each case, 2 controls (matched for disease duration and age) were randomly selected among patients with primary SS and without lymphoma. Cases and controls were compared using univariate analysis and then using multivariate analysis to identify independent predictors of lymphoma. RESULTS: One hundred one patients with primary SS and lymphoma were included. Eighty-seven patients were women (86.1%), and the mean ± SD age at lymphoma diagnosis was 57.4 ± 12.6 years. The most frequent histologic type was B cell non-Hodgkin's lymphoma (NHL) in 99 of 101 patients, with marginal-zone lymphoma in 76 of the 99 patients (76.8%) including 58 (58.6%) with lymphoma of the mucosa-associated lymphoid tissue type. Lymphomas were most frequently located in the salivary glands (43 patients). A specific treatment was initiated at diagnosis in 87 patients with B cell NHL, and 61 patients (61.6%) achieved complete sustained remission after the first line of treatment. In the multivariate analysis, salivary gland enlargement, the presence of rheumatoid factor (RF), low C4, cryoglobulinemia, lymphopenia, and disease activity according to the European League Against Rheumatism Sjögren's Syndrome Disease Activity Index (excluding the lymphoma domain) were found to be predictors of lymphoma. No previous treatment for primary SS was associated with any effect on lymphoma occurrence. CONCLUSION: In addition to previously known factors predictive of lymphoma occurrence, the independent roles of RF and disease activity were demonstrated in this case-control study of primary SS-associated lymphoma. Our findings highlight the roles of chronic antigenic stimulation and disease activity in the development of this severe complication.

Synthesis and structure-activity relationships of novel benzimidazole and imidazo[4,5-b]pyridine acid derivatives as thromboxane A2 receptor antagonists.

A series of 1-benzylbenzimidazole and 3-benzylimidazo[4,5-b]pyridine substituted in the 2-position by an alkanoic or mercaptoalkanoic acid chain was synthesized for evaluation as potential thromboxane A2/prostaglandin H2 (TXA2/PGH2) receptor antagonists. The affinity of each compound for washed human platelet TXA2/PGH2 receptors was determined by radioligand binding studies using [125I]PTA-OH. Structure-activity relationships led to the conclusions that 2-alkanoic acid derivatives were slightly more potent than 2-mercaptoalkanoic acids and that compounds possessing a 3,3-dimethylbutanoic acid in the 2-position were definitely the most potent with Ki values of 4-39 nM (11a, 11g-x, 37a, 37f-o, 23a-c). The replacement of this 3,3-dimethylbutanoic acid side chain by a shorter one led to a marked decrease of affinity (11b and 11c; Ki = 5600 and 1700 nM, respectively). Compounds of benzimidazole and imidazo[4,5-b]pyridine series displayed similar potencies (11q and 23c have Ki values of 6 and 7 nM, respectively). The interesting pharmacological profile of compound 23a (UP 116-77: 4-[3-[(4-chlorophenyl)methyl]-6-chloroimidazo[4,5-b]pyridin-2-yl]- 3,3-dimethylbutanoic acid) and its excellent tolerance led us to select this derivative for further development.

Metastatic phenotype of murine tumor cells expressing different cooperating oncogenes.

Four murine cellular tumor models expressing various combinations of oncogenes (SV40 large T and v-Ha-ras, SV40 large T and v-src, SV40 large T and neu, adenovirus EIA and v-Ha-ras) induce sarcoma when they are inoculated s.c. into the DBA/2 syngenic mice. The metastatic patterns, distribution and fate of these tumor cells transplanted by two different routes into syngenic DBA/2 mice have been studied. All the tumor cell lines except EIA-ras, induce massive overt artificial metastases principally in the lung after i.v. injection. In s.c. tumor-bearing mice, a few resting cells colonize the lung as micrometastases. When removed from this tissue context and injected s.c. these cells regain their proliferative potential and grow as local tumors which again give rise to occult pulmonary micrometastases.

Stable cell line of T-SV40 immortalized human glomerular visceral epithelial cells.

Human subcultures (third passage) of glomerular visceral epithelial cells (VEC) isolated from one month old kidney were successfully transfected by two recombinant plasmids containing the cloned oncogenes from the simian virus 40 large T antigen and H-ras gene. One postcrisis cell clone (56/10 A1) was selected, propagated and characterized. One hundred percent of the 56/10 A1 cells (current passage greater than 100th; doubling time 30 hrs) expressed the nuclear T-SV40 antigen assayed by IF; the cells failed to express H-ras (RNA blot analysis). Immortalized cells were morphologically and phenotypically compared to parental cell type (third passage). Phenotypic characterization of the 56/10 A1 cells was achieved using indirect immunofluorescence (IF) and immunogold silver staining coupled to bright field and epipolarization microscopy. Both parental and 56/10 A1 cells displayed positivity for cytokeratin, CALLA and PHM5, whereas von Willebrand factor was not detected in the two cell types. Since we have previously shown that human glomerular epithelial cells in culture synthetize plaminogen activator (PA) related compounds, we investigated the secretion pattern of these products in parental and transfected cells. Zymographic analysis of secreted PA related compounds revealed production of free urokinase (u-PA) and type 1 plasminogen activator inhibitor (PAI-1) complexed to tissular plasminogen activator (t-PA). Finally, in the transfected cells, increased cGMP generation under atrial natriuretic factor (ANF) stimulation agreed with previous work performed on nontransfected human VEC. In conclusion, the establishment of a human permanent cell line which retains most of the phenotypic features of parental glomerular visceral epithelial cells should represent a new tool to study human glomerular cell functions.