Internal Medicine II Practice Test

In Sjögren's syndrome, the risk of developing lymphoma is linked to evidence of abnormal B-cell activity, and cryoglobulinemia is a key indicator of that process. Cryoglobulins are immunoglobulins that precipitate at cold temperatures and reflect a clonal or oligoclonal B-cell proliferation with immune complex formation. This underlying B-cell dysregulation correlates with an increased risk of lymphoproliferative disorders, including lymphoma, in Sjögren's patients. Cryoglobulinemia is often accompanied by reduced complement levels due to immune complex–mediated activation, which further signals active immune dysregulation. The other options don’t carry the same risk signal. A negative salivary gland biopsy would not specifically indicate higher lymphoma risk. Renal tubular acidosis is a renal manifestation of Sjögren's, not a marker for lymphoma risk. Hypercomplementaemia (elevated C4) is not characteristic of the cryoglobulin–associated processes seen with escalating lymphoma risk; in fact, complement is typically consumed, leading to lower levels.