Hypercalcaemia and increased serum interleukin-6 levels induced by all-trans retinoic acid in patients with multiple myeloma.
All-trans retinoic acid (ATRA) inhibits human myeloma cell growth in vitro, presumably through the down-regulation of interleukin 6 receptors (IL-6R). Based on these and other studies, we initiated a phase II clinical trial using ATRA in patients with advanced refractory multiple myeloma (MM). We report that three out of six treated patients developed severe hypercalcaemia following administration of ATRA, which was accompanied by a significant rise in serum IL-6 levels. Normal calcium levels were restored after the discontinuation of the drug and the administration of standard anti-hypercalcaemic care. We suspect that down-regulation of IL-6R resulted in increased serum IL-6 levels, leading to advanced bone resorption and hypercalcaemia. We conclude that the use of ATRA in patients with advanced MM is not warranted.
Department of Medicine, Memorial Sloan-Kettering Cancer Center, New York, N.Y. 10021.
R
R
Niesvizky
D S
DS
Siegel
X
X
Busquets
G
G
Nichols
J
J
Muindi
R P
RP
Warrell
J
J
Michaeli
D006801:Humans; D006934:Hypercalcemia / Q000139:chemically induced*; D015850:Interleukin-6 / Q000097:blood*; D009101:Multiple Myeloma / Q000097:blood / Q000188:drug therapy*; D014212:Tretinoin / Q000009:adverse effects* / Q000627:therapeutic use
D015850:Interleukin-6; D014212:Tretinoin