Suppression of lymphocyte responses by monocytes with untreated and treated
multiple myeloma
JJ Twomey, AH Laughter, L Rice and RJ Ford
Studies were performed on 15 untreated and 14 treated patients with
multiple myeloma. The monocyte content was normal in blood but elevated in
mononuclear leukocytes (MNL) from treated but not untreated patients (p
less than 0.001). This correlated with the severity of lymphopenia in blood
(p less than 0.01). Three patterns of immunoglobulin(Ig) synthesis emerged.
(1) Most untreated patients showed normal polyclonal responses to pokeweek
mitogen. (2) Of 12 treated patients, the 8 whose MNL included greater than
30% monocytes had subnormal Ig responses to pokeweek mitogen. Ig synthesis
increased when adherent cells that suppressed Ig synthesis were depleted.
Suppression in vitro bore no relationship to polyclonal immunoglobulin
levels in serum. (3) Three patients had early blood invasion by
plasmacytoid cells. Their MNL spontaneously released large amounts of the
Ig class of their serum gammopathies. Proliferative responses to
phytohemagglutinin by MNL from all patients were reduced, in part due to
monocytoid cell suppression and in part to intrinsic T-cell
hyporesponsiveness. B- and T-cell responses in vitro are sometimes
suppressed with myeloma. This is related to elevated monocyte percentages
in MNL preparations. This excess of monocytes is a function of lymphopenia
secondary to therapy, rather than the primary malignant process itself. No
evidence was found that suppression by monocytes is qualitatively altered
by myeloma or its treatment.
Volume 60,
Issue 2,
pp. 316-322,
08/01/1982
Copyright © 1982 by The American Society of Hematology
