Medline ® Abstracts for References 83,84

The immunoglobulin levels and autoantibody profiles of 104 patients with primary myelodysplastic syndromes (MDS), classified according to the FAB criteria, were analysed. Eight patients, four with coexistent non-Hodgkin's lymphomas, three with chronic lymphocytic leukaemia and one with a lymphoplasmacytoma, were excluded from the final analysis of immunoglobulin levels. Serum protein electrophoresis and immunoelectrophoresis revealed the presence of monoclonal gammopathy in 12 patients (12.5%). Of the remaining 84 patients, a polyclonal rise in serum immunoglobulins was present in 27 (32%) while a further 16 (19%) had low immunoglobulin levels. The direct antiglobulin test was positive in eight out of 98 patients tested (8.1%), and organ and non-organ specific autoantibodies were present in 15 out of 67 patients tested (22.3%). Two patients had associated pernicious anaemia (PA), two hypothyroidism, and one PA with hypothyroidism. Three patients had sero-negative rheumatoid arthritis. These results demonstrate that there is a high incidence of immunological abnormalities in MDS.

PURPOSE: We hypothesized that surrogate markers of host immune response may predict survival in myeloid malignancies. Because of immediate practical applicability, we chose plasma immunoglobulin free light chain (FLC) concentration as the biomarker of interest.

PATIENTS AND METHODS: Two independent cohorts of patients with primary myelofibrosis (PMF) or myelodysplastic syndromes (MDS) were studied. Kappa (κ) and lambda (λ) FLCs were measured by a quantitative nephelometric assay. Patients with monoclonal FLC were excluded.

RESULTS: Values that were above the upper limit of normal forκorλFLC were documented in 33% of 240 patients with PMF and 46% of 74 patients with MDS. Increased FLC was significantly associated with increased creatinine, and advanced age in PMF (P<.001) and hemoglobin less than 10 g/dL in MDS (P = .005). In multivariable analysis, increased FLC predicted shortened survival in both PMF and MDS, independent of age, creatinine, and other conventional risk factors. Cutoff levels based on receiver operating characteristic analysis forκplusλtotal FLCs delineated risk groups with highly significant differences in overall survival; International Prognostic Scoring System-adjusted hazard ratio in PMF was 1.9 (95% CI, 1.3 to 2.7), and was 6.3 (95% CI, 2.7 to 16.6) in MDS. No correlations were seen with leukemia-free survival, karyotype, or JAK2, MPL, or IDH mutations. In patients with PMF who were studied by cytokine profiling, the prognostic value of an increased FLC level was independent of that from circulating interleukin-2 receptor (IL-2R) or IL-8 levels.

CONCLUSION: Increased plasma FLC concentration predicts inferior survival in both PMF and MDS. Its lack of correlation with leukemia-free survival and tumor-specific genetic markers suggests a primarily host-driven biologic phenomenon that might be more broadly applicable.