[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 (<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 (<0.05). β-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 (<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 (=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 (<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 (<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.