The role of interleukin-6 in cases of cardiac myxoma - Clinical features, immunologic abnormalities, and a possible role in recurrence

We performed this prospective study to evaluate the correlation of interleu kin-6 serum levels with preoperative constitutional symptoms and immunologi c abnormalities, and the possible role played by this cytokine in tumor rec urrence. Eight patients with atrial myxoma were evaluated at our institution from Ju ly 1993 to November 1998. We measured their interleukin-g serum levels by e nzyme-linked immunosorbent assay method preoperatively and 1 and 6 months a fter surgery. Two of the cases involved recurrent rumor: 1 patient had unde rgone his 1st surgery at a different institution and died during the 2nd pr ocedure, so his data were incomplete. Preoperatively, the whole group of patients had elevated interleukin-6 seru m levels. Although patients with a Ist occurrence of tumor demonstrated a p ositive correlation between interleukin-6 serum level and tumor size, the 2 patients with recurrent tumors appeared to have higher interleukin-g level s regardless of tumor size. Once the tumor was surgically removed, interleu kin-6 levels returned to normal values, and this was associated with regres sion of clinical manifestations and immunologic features. According to our study, the overproduction of interleukin-6 by cardiac myxo mas is responsible for the constitutional symptoms and immunologic abnormal ities observed in patients with such tumors and might also play a role as a marker of recurrence. This study also suggests that recurrent cardiac myxo mas form a subgroup of cardiac myxomas with a highly intrinsic aggressivene ss, as implied by their greater interleukin-6 production despite their smal ler size. Further studies are needed to confirm these results.