title: Evaluation of serum deoxythymidine kinase as a marker in multiple myeloma.
abstract: A recently developed deoxythymidine kinase assay utilizing 125I-iododeoxyuridine as substrate was used in an investigation of sera from 122 untreated patients with multiple myeloma. Most patients had slightly elevated or normal serum deoxythymidine kinase activity (S-TK), although in some patients values increased by more than forty-fold were found. S-TK correlated with the haemoglobin level but did not correlate with sex, age, erythrocyte sedimentation rate, nor with the serum concentrations of creatinine, beta 2-micro-globulin, Ca or M-component. The distribution of S-TK values in IgG, IgA and pure Bence-Jones myeloma did not differ significantly. Patients with IgG and IgA myeloma excreting light-chain immunoglobulin in the urine had significantly higher S-TK than non-excreters. There was a significant correlation between S-TK values and tumour cell mass as determined by clinical staging. A high pretreatment S-TK (greater than 5.1 units) also distinguished a group of patients with a significantly shorter survival time. Patients with no response to initial therapy had significantly higher S-TK values than those who did respond. In longitudinal studies of 11 patients, S-TK was found to increase when the disease became more aggressive. The possibility of diagnosing disease progression at an early stage by an elevation of S-TK is discussed.
mesh_terms: D000328:Adult; D000368:Aged; D004796:Clinical Enzyme Tests; D005069:Evaluation Studies as Topic; D005260:Female; D006801:Humans; D007136:Immunoglobulins / Q000032:analysis; D008297:Male; D008875:Middle Aged; D009101:Multiple Myeloma / Q000097:blood / Q000175:diagnosis* / Q000628:therapy; D011379:Prognosis; D013937:Thymidine Kinase / Q000097:blood*
chemical_list: D007136:Immunoglobulins; D013937:Thymidine Kinase