Affiliations: [a] Department of Hematology, Trakya University Medical Faculty, Edirne, Turkey | [b] Department of Rheumatology, Trakya University Medical Faculty, Edirne, Turkey
Abstract: BACKGROUND: Apelin/APJ system regulates angiogenesis and is
overexpressed in some malignancies. Apelin can induce lymphangiogenesis and
lymph node metastasis. OBJECTIVE: We evaluated apelin levels in multiple myeloma (MM) and
non-Hodgkin lymphoma (NHL); and analyzed the association between apelin
levels and clinical findings. METHODS: We included consecutive 29 MM, 31 NHL patients, and 19 healthy
controls. Patients' demographic and clinical features, treatment modalities,
and responses were recorded from hospital records. Plasma apelin was
determined by enzyme-linked immunosorbent assay (ELISA). RESULTS: MM patients had significantly higher plasma apelin level than NHL
and healthy control groups (p< 0.001). Apelin level in NHL group was similar
to controls (p> 0.05). ROC curve analysis showed that the area under the
curve value for apelin level in MM was 0.842 ng/ml (95%CI: 0.739-0.945,
p< 0.001). Plasma apelin level ≥ 0.827 ng/ml had 76% sensitivity and
86% specificity for the diagnosis of MM. Multivariate Cox regression
analysis showed that MM patients with high apelin level had better prognosis
and patients with advanced stage of disease (ISS-3) had significantly poor
prognosis when compared to others. In the MM group, apelin level correlated
negatively with LDH (r = -0.39, p= 0.038). CONCLUSIONS: In MM, plasma apelin level was significantly higher than in
NHL and control groups. Apelin could be playing a role in MM pathogenesis;
and apelin level could be used as a diagnostic and prognostic biomarker in
MM.
