Microsatellite instability is a common finding in multiple myeloma.

PURPOSE: Microsatellite instability (MSI) occurs as a result of sliding in the DNA sequences from shortening or elongation of the repeat zones of DNA during replication. Such abnormalities can normally be corrected by the enzymes coded by the DNA mismatch repair (MMR) genes. Therefore, detection of MSI is considered to be a sign of disorder of the MMR genes and is interpreted as a replication error phenotype. PATIENTS AND METHODS: We evaluated the MSI in 5 different loci in the 14q32 region of immunoglobulin heavy chain IgH gene in 26 newly diagnosed patients with multiple myeloma (MM). RESULTS: Fifty-four percent of the patients disclosed MSI and at least 1 locus but no significant association of MSI was found between different clinical stages and the MM subtype. MSI was not found in 5 light-chain myeloma patients. CONCLUSION: Although our case number is small, probably the genomic instability in heavy-chain MM may be a common finding and probably plays a critical role in the MM pathogenesis.

Diagnostic performance of minor salivary gland biopsy, serological and clinical data in Sjögren's syndrome: a retrospective analysis.

The aim of this study was to investigate the performance of minor salivary gland biopsy (MSGB), serological and clinical data in diagnosis of primary Sjögren's syndrome (pSS). Retrospective review of 216 patients who underwent minor labial salivary gland biopsy in last 5 years was performed. Results of the patients with diagnosis of pSS were compared with the patients failing to fill the classification criteria of pSS. Two groups did not differ significantly in terms of clinical symptoms and signs except presence of Raynaud's phenomenon. Specificity and positive likelihood ratio of clinical signs in diagnosis of pSS were quiet low. A total of 78.7% of pSS patients had a focus score >or=1 (Chiscolm's score III/IV) while all of the non-SS patients had a focus score <1 (P < 0.001). MSGB has the best predictive value with highest sensitivity and specificity for pSS diagnosis. Serological markers have higher predictive values compared to clinical symptoms and signs. Presence of Raynaud's phenomenon, lymphopenia and/or hypergammaglobulinemia strengthens the probability of pSS in a patient with sicca symptoms.