Antibacterial antibodies suppressed among MM patients

Despite infection being a common complication of multiple myeloma (MM), antibacterial antibodies seem to be present in low levels, a recent study has found.

The findings “demonstrate the need to protect patients against infections at diagnosis, during anti-myeloma therapy, and importantly also during remission phases. Prophylactic antibiotics and patient education should be considered during active disease/when patients are undergoing therapy,” said the researchers.

The study included 836 MM patients (median age, 67 years; 63 percent male) enrolled in the TEAMM* trial. At diagnosis, serum levels of polyclonal immunoglobulin (Ig) G, A, and M were below the reference range in 71 percent, 83 percent, and 90 percent of the patients, respectively.

In 196 patients with paired follow-up data for IgG, median levels increased from 4.4 to 6.6 g/L over 1 year, with the proportion of patients with IgG within the reference range growing from 25 percent to 57 percent. A similar effect was reported for IgA and IgM.

Similarly, only 20 percent of the MM patients had protective IgG antibody levels against any of the 19 bacterial antigen targets assessed. Among healthy controls, 55 percent had such protection. As an illustration, only pneumococcal serotype 14 had adequate protection in MM patients, with 60 percent achieving acceptable serum thresholds.

Over a year of follow-up, the antibody levels against polysaccharide antigens further dropped, as did the proportion of patients protected. For haemophilus and meningococcal serotypes C, W, and Y, most patients saw antibody levels 50–100-times weaker than the protective threshold.

*Tracking early morbidity and mortality in myeloma