RESUMO
Objective:To investigate the expressions of CD200 and inducible costimulator (ICOS) protein in angioimmunoblastic T-cell lymphoma (AITL) and the relationship with prognosis as well as their significances in the differential diagnosis of AITL.Methods:A total of 39 AITL patients in the First People's Hospital of Chenzhou, the Fourth People's Hospital of Chenzhou, Xiangnan College Affiliated Hospital and Chenzhou 3rd People's Hospital from June 2012 to December 2019, and 10 patients with classic Hodgkin lymphoma (CHL) and 10 patients with peripheral T cell lymphoma, not otherwise specified (PTCL-NOS) from August 2016 to July 2019 in the First People's Hospital of Chenzhou were selected. Immunohistochemistry was used to detect the expressions of CD200, ICOS, CD10, programmed death 1 (PD-1), bcl-6 and CXC chemokine receptor-13 (CXCL13) proteins, and the correlation of CD200 and ICOS with clinicopathological features and prognosis of AITL patients was analyzed, and the diagnostic significance of both in differentiating AITL from PTCL-NOS and CHL was also analyzed.Results:The positive rates of CD200 and ICOS in 39 AITL patients were 71.79% (28/39) and 61.54% (24/39), respectively. There were 7 cases of CD200 weak and moderate positive in 10 CHL patients, and ICOS proteins were all negative. Among 10 PTCL-NOS patients, 4 patients had CD200 positive and 1 patient had ICOS positive. The differences in positive rates of ICOS protein between AITL patients and CHL, PTCL-NOS patients were statistically significant (all P < 0.05); the differences in positive rates of CD200 protein between AITL patients and CHL, PTCL-NOS patients were not statistically significant ( χ2=0.013, P=0.911; χ2=3.551, P=0.060). The positive rate of CD200 in AITL patients with elevated lactate dehydrogenase (LDH) and international prognostic index (IPI) score of 3-4 was higher than that in AITL patients with normal LDH and IPI score of 0-2 (both P < 0.05); The positive rate of ICOS in AITL patients with elevated LDH and PD-1 positive was higher than that in AITL patients with normal LDH and PD-1 negative (both P < 0.05). CD200 negative AITL patients had better 3-year overall survival (OS) rate (4.2% vs. 66.7%) and 3-year progression-free survival (PFS) rate (5.3% vs. 77.1%) compared with those in CD200 positive AITL patients, and the differences between both groups were statistically significant (both P < 0.01); there was a statistically significant difference in 3-year OS rate between ICOS positive AITL patients and ICOS negative AITL patients (15.3% vs. 38.6%, P=0.011), while there was no statistically significant difference in 3-year PFS rate of both groups (18.6% vs. 41.5%, P=0.059). Multivariate analysis showed CD200 ( HR=0.076, 95% CI 1.555-79.497, P=0.001), extranodal involvement or not ( HR=11.117, 95% CI 1.555-79.497, P=0.016) and LDH ( HR=2.147, 95% CI 0.844-5.459, P=0.109) were independent influencing factors of OS in AITL patients; CD200 ( HR=0.075, 95% CI 0.016-0.357, P=0.001) and LDH ( HR=2.335, 95% CI 0.929-5.870, P=0.071) were independent influencing factors of PFS in AITL patients. Conclusions:CD200 and ICOS can be used as immunohistochemical indicators to assist the diagnosis of AITL patients. ICOS protein helps to differentiate AITL from CHL and PTCL-NOS; CD200 can be used as indicators to judge the prognosis and deterioration of AITL patients.