[Clinical Significance of CD28 Expression in Newly Diagnosed Multiple Myeloma].

OBJECTIVE:To explore the expression of CD28 in multiple myeloma and its correlation with tumor burden and clinical prognosis. METHODS:Flow cytometry was adopted to analyze bone marrow specimens of 91 newly diagnosed patients with multiple myeloma. According to CD28 expression, the patients were divided into CD28+ group and CD28- group, and the differences between the two groups in clinical features, genetic abnormalities, and treatment response were compared. Staging was carried out in accordance with the International Staging System (ISS). RESULTS:Among 91 newly diagnosed patients, there were 31 cases in CD28+ group and 60 cases in CD28- group. The proportion of ISS-Ⅲ patients in the CD28+ group was 70.97%, which was higher than 50.00% in the CD28- group (P<0.05). The median of bone marrow plasma cells in the CD28+ group was 41.78(2.00-77.00), which was higher than 26.92(2.00-92.00) in the CD28- group (P<0.05). β2-microglobulin level in the CD28+ group was 6.53(2.11-36.50) mg/L, which was higher than 5.76(2.00-31.34) mg/L in the CD28- group (P<0.05). The positive rate of poor karyotype in the CD28+ group was 70.00% (21/30), which was higher than 45.00% (27/60) in the CD28- group (P=0.025). After 4 cycles of chemotherapy, the total effective rate of CD28- group was 86.27%, which was higher than 60.00% of CD28+ group (P<0.05). After a median follow-up of 10 months, the progression-free survival (PFS) time of CD28+ group was 10.7 months, which was lower than 14 months of CD28- group (P<0.05). Univariate analysis showed that age ≥ 65 years old, hemoglobin < 60 g/L, ISS-III, CD28+ expression and ≥ 2 genetic abnormalities were not risk factors for PFS, while further multivariate analysis showed that induction effect < partial response (PR) and CD28+ expression and were independent risk factors for PFS. CONCLUSION:CD28+ is associated with clinical characteristics and prognosis of newly diagnosed multiple myeloma patients, and can be used as a reference index to evaluate the prognosis.