{
  "abstract": "Background To evaluate the relationship between peripheral blood immune factors, autoantibody profiles, and biochemical markers with the efficacy of PD-1 monoclonal antibody (PD-1 mAb) therapy in advanced gastric cancer, and to construct a combined predictive model.Methods A retrospective study was conducted with 80 patients with advanced gastric cancer who received PD-1 mAb therapy. Peripheral blood samples were collected before and early during treatment. The levels of TNF-α, ANA, Anti-MCV, APF, AKA, RF, anti-EPCR antibodies, LDH, CK, and ALT were measured. Objective response was assessed according to the RECIST criteria. Logistic regression and ROC curve analysis were used to construct the combined predictive model.Results Among the 80 patients, 34 were classified as the objective response group (CR+PR group) and 46 as the non-response group (SD+PD group). Compared to the non-response group, the response group showed significant immune activation features. The following differences between the groups were statistically significant: TNF-α [92.4 vs. 31.2 pg/mL, P<0.001], ANA titer (1:380 vs. 1:63, P<0.001), ANA positivity rate [82.4% vs. 19.6%, P<0.001], and Anti-MCV levels [168.9 vs. 29.7 U/mL, P<0.001]. The positivity rates of APF and AKA were significantly higher in the response group (P<0.001). No significant differences were observed between the groups for RF and anti-EPCR antibodies (P>0.05). The five-marker combined model, based on TNF-α, ANA, Anti-MCV, LDH, and CK, had an AUC of 0.942 (95% CI: 0.868–1.000), with a sensitivity of 96.2% and a specificity of 94.1%.Conclusions Peripheral immune activation phenotypes (e.g., elevated TNF-α, ANA, and Anti-MCV) are significantly associated with objective responses in advanced gastric cancer patients receiving PD-1 mAb therapy. The five-marker combined model demonstrated high predictive performance in this single-center retrospective cohort, suggesting that peripheral blood immune profiling may serve as a candidate biomarker for PD-1 mAb efficacy stratification. Given the limited sample size and lack of external validation, further confirmation in larger, prospective, and multicenter studies is necessary.",
  "authors": [
    {
      "affiliations": [
        "Baotou Cancer Hospital, China"
      ],
      "name": "Yunqi Hua"
    },
    {
      "affiliations": [
        "Baotou Medical College, China"
      ],
      "name": "Yubo Liu"
    },
    {
      "affiliations": [
        "Baotou Medical College, China"
      ],
      "name": "Fengqi Liu"
    },
    {
      "affiliations": [
        "Baotou Cancer Hospital, China"
      ],
      "name": "Xiang Zhuang"
    },
    {
      "affiliations": [
        "Baotou Cancer Hospital, China"
      ],
      "name": "Shuang Lv"
    },
    {
      "affiliations": [
        "Baotou Cancer Hospital, China"
      ],
      "name": "Lina Wang"
    }
  ],
  "title": "IDDF2026-ABS-0230 Peripheral blood immune profiling in predicting efficacy of PD-1 monoclonal antibody therapy in advanced gastric cancer: a retrospective study",
  "uid": "4a4606f5-8eaf-5d8c-a962-7b25ea59e2b0"
}