Factors Predicting Spontaneous Regression in Other Iatrogenic Immunodeficiency-Associated Lymphoproliferative...

Other iatrogenic immunodeficiency-associated lymphoproliferative diseases (OIIA-LPDs) occur in patients taking immunosuppressive drugs (ISDs) for autoimmune diseases, such as rheumatoid arthritis and have been suggested to be associated with Epstein-Barr virus (EBV) infection. Although some patients regress spontaneously upon discontinuation of ISDs, factors predicting spontaneous regression (SR) remain controversial. Therefore, we conducted a retrospective observational study of the clinical characteristics and factors associated with treatment response, prognosis, and SR in patients diagnosed with OIIA-LPD.

We analyzed 82 patients at two institutions between 2002 and 2022, 41 (50%) of whom had SR after discontinuation of ISDs, with a 5-year overall survival (OS) rate of 86.3% and a median follow-up of 48 months (range, 9-201 months).

The 5-year survival rates of the SR and non-SR groups were 96.9% and 77.2%, respectively. This value was significantly higher in the SR group (P = .001). The 5-year progression-free survival (PFS) rate for all patients was 60.1%, whereas the PFS rate for patients in the non-SR group who required chemotherapy was 54.4%. In univariate analysis, localized stage, good performance status, positive EBV-encoded RNA in situ hybridization (EBER-ISH) results, low C-reactive protein level, and low soluble interleukin-2 receptor (sIL-2R) level were associated with SR. Multivariate analysis revealed that EBER-ISH positivity and low sIL-2R levels were associated with SR (P = .016 and .012, respectively).

The OS was significantly longer in the SR group than in the non-SR group. EBER-ISH and sIL-2R levels are predictors of SR.