Prognostic significance of the immunological variant in patients with multiple myeloma

The prognostic significance of the immunological variant and especially of the type of light chain secretion in multiple myeloma is controversially assessed in the literature.

To study the prognostic significance of the class and type of the monoclonal production in patients with multiple myeloma.

109 patients with multiple myeloma were enrolled, in the study, diagnosed and treated at the University Clinic. The class and type of the paraprotein secretion was determined using immune electrophoresis of serum and/or urine by Grabar and Williams, Mancini radial immunodiffusion and Ouchterlony immunodiffusion for light chain typing. The median survival (MS) was calculated using the method of maximal logarithmic authenticity, where the survival in months = log t.

The MS of all patients was 29 months. Patients with Bence Jones myelomas showed the lowest survival--12 months; followed by those with IgD myelomas--20 months. The patients with combined and non-combined light chain production (BJ+) lived 26 months, with BJ(-)--35 months (inauthentic difference). No difference was found between the survival of BJ(kappa)--30 months and BJ(lambda)--21 months. BJ(+) patients with myeloma nephropathy and nitrogen retention had a MS of 23 and 20 months, respectively, as compared with the BJ(+) patients without myeloma nephropathy and nitrogen retention: 47 and 40 months (p < 0.05).

The class of the paraprotein secretion only and the two types of light chain separately do not possess any prognostic significance. From a quantitative point of view the class and type of paraprotein production are independent staging criteria with certain predictive value. The prognostic significance of BJ-proteinuria is found making comparison between the groups in which its pathogenic effect is expressed.