The La/SS-B antigen is a 47 kD ribonucleic protein that is associated with a spectrum of small RNAs (2). La/SS-B appears to be readily susceptible to proteolysis, resulting in many smaller (42kD, 320, and 270) but still immunoreactive polypeptides (3). It has been shown that the La/SS-B antigen primarily resides in the nucleus (2), and it appears to be associated with RNA polymerase III transcripts (4). It has also been shown that the La/SS-B antigen shows strong conservation across species (5). Anti-La/SS-B autoantibodies were described originally as precipitating autoantibodies in sera of Sjogren’s Syndrome patients and referred to as SjT.(1) A precipitin with the same properties was rediscovered later and termed La and then SS-B. Anti-La/SS-B precipitins are most commonly found in Sjogren’s Syndrome and Systemic Lupus Erythematosus (SLE). The presence of autoantibodies against the La/SS-B antigen has been advocated as a diagnostic aid in Sjogren’s Syndrome patients (6). Autoantibodies against La/SS-B are also commonly found in Systemic Lupus Erythematosus and Subacute Cutaneous Lupus (4). In addition, there appears to be a correlation between anti-La/SS-B and the absence of nephritis in SLE patients. Studies have demonstrated that SLE patients with precipitating Anti-Ro/SS-A antibodies have a high incidence of serious nephritis (53%), while those with both Anti-Ro/SS-A and Anti-La/SS-B have a low (9%) frequency of nephritis (7).