title: Diurnal variations of serum beta 2-microglobulin in multiple myeloma.
abstract: The chronobiological circadian behaviour in serum levels of beta 2-microglobulin has been investigated in three groups of subjects: (A) 6 healthy controls; (B) 6 patients with untreated multiple myeloma; (C) 6 patients with multiple myeloma in complete remission after polychemotherapy. From all subjects, under the same standard life conditions, venous blood samples were drawn at 4-hour intervals starting from midnight during the span of a whole day. Circulating serum beta 2-microglobulin levels were determined by RIA method. The time-related data were analyzed by chronograms and the "mean-group cosinor" method. A significant circadian rhythm for serum beta 2-microglobulin was detected in the control group, with a peak in the morning hours, and in untreated patients, with a peak in the afternoon hours. No significant rhythm was found in treated patients with multiple myeloma. A significant mesor reduction was noted in patients with complete remission, correlated with the absence of circadian rhythm, in respect to untreated patients. These data suggest that serum levels of beta 2-microglobulin could be related to the neoplastic plasma cell proliferation and to the effect of therapy, and that the circadian evaluation could be used as a guide in monitoring myeloma patients.
authors.affiliation: Department of Internal Medicine, School of Medicine and Surgery, University of L'Aquila, Italy.
authors.forename: P
authors.initials: P
authors.lastname: Pasqualetti
authors.forename: R
authors.initials: R
authors.lastname: Casale
authors.forename: D
authors.initials: D
authors.lastname: Colantonio
authors.forename: A
authors.initials: A
authors.lastname: Collacciani
authors.forename: G
authors.initials: G
authors.lastname: Natali
mesh_terms: D002940:Circadian Rhythm; D006801:Humans; D008297:Male; D008558:Melphalan / Q000627:therapeutic use; D009101:Multiple Myeloma / Q000097:blood* / Q000188:drug therapy; D011241:Prednisone / Q000627:therapeutic use; D011292:Premedication; D011863:Radioimmunoassay; D001613:beta 2-Microglobulin / Q000378:metabolism*
chemical_list: D001613:beta 2-Microglobulin; D008558:Melphalan; D011241:Prednisone