Pretreatment Prognostic Nutritional Index Is Associated with Treatment Response and Survival in Patients with Relapsed or Refractory Non-Hodgkin Lymphoma Receiving CAR-T Cell Therapy

Background: Clinical outcomes after CAR-T therapy vary substantially in patients with relapsed or refractory B-cell non-Hodgkin lymphoma (r/r B-NHL), and practical markers available before infusion are still limited. The prognostic nutritional index (PNI), calculated from serum albumin and absolute lymphocyte count, reflects both nutritional and immune condition. Whether pretreatment PNI has prognostic value in patients treated with TanCAR7 remains unclear. Methods: We performed a retrospective analysis of patients with r/r B-NHL who received TanCAR7, a tandem CD19/CD20-directed CAR-T product, in a single-center phase I/II trial. Pretreatment PNI was assessed using routine laboratory data obtained before lymphodepletion and infusion. Associations between PNI and treatment response, progression-free survival (PFS), and overall survival (OS) were analyzed. Survival outcomes were evaluated with Kaplan–Meier methods and Cox regression models. Results: A total of 64 patients were included in the final analysis, including 27 patients in the low-PNI group and 37 in the high-PNI group. Patients with high pretreatment PNI had a significantly higher complete response rate (81.1% vs. 51.9%, p = 0.021) and objective response rate (89.2% vs. 63.0%, p = 0.024) than those with low pretreatment PNI. Kaplan–Meier analysis showed that high pretreatment PNI was associated with longer PFS (p = 0.006) and OS (p = 0.012). In multivariable analysis, high pretreatment PNI remained associated with improved PFS (HR = 0.202, 95% CI 0.076–0.538, p = 0.001) and OS (HR = 0.217, 95% CI 0.084–0.564, p = 0.002), although these estimates should be interpreted cautiously given the limited number of events and the apparent time-varying effect of PNI. Time-dependent ROC analysis showed that pretreatment PNI had better discriminative performance for shorter-term outcomes, particularly within the first 1–2 years after infusion. Conclusions: In patients with r/r B-NHL treated with TanCAR7, pretreatment PNI was associated with treatment response and survival. As a simple index derived from routine laboratory tests, PNI may help refine pretreatment risk assessment and identify patients who may benefit from closer early monitoring and supportive care. Prospective validation in larger cohorts is needed.