Serum immune complexes and rheumatoid factors in superficial bladder tumours

Serum immune complex (IC) and rheumatoid factor (RF) levels of 39 patients with a transitional cell tumour of the bladder were analyzed using 4 different IC and 2 RF assays. Elevated serum immune complex and rheumatoid factor levels were observed in the majority of the patients (95%). Conglutinin-binding (KgB), C1q-binding (C1qB), platelet iodinated protein A test (PIPA) and RF-enzyme immunoassay (RF-EIA) gave positive results in 31%, 62%, 23% and 31% of the cases, respectively and separated cancer sera from normal blood donors (p less than 0.001). Elevated titers were also observed with platelet aggregation test (PAT) and latex agglutination for RF in 23% and 67% of the cases, respectively. A negative correlation (p less than 0.01) was observed with the stage of the disease and RF-values. Other IC tests did not correlate significantly with stage, histological grade or progression of the disease. The best prognostic marker was the histological grade of the tumour. Males had more undifferentiated tumours than females. Multivariate analysis was carried out to correlate several laboratory parameters simultaneously with clinical variables and it revealed that elevated IC tests values (KgB, C1qB and PIPA) and low RF-values correlated to stage (p = 0.009) but not to histological grade or progressive course of the disease.