Those who developed MALT NHL had a higher frequency at diagnosis of cryoglobulins (P = 0.002), low C3 levels (P = 0.018), high EULAR SS disease activity index (ESSDAI) score of 4 or more (P = 0.001), and high joint DAS score (P < 0.001), while the risk of non-MALT B cell lymphomas was unrelated to systemic activity, with anaemia, monoclonal gammopathy, cryoglobulins and low C4 levels at SD diagnosis being the main risk factors. This evidence concerns the gene C3 and anemia (phenotype).