ABSTRACT ObjectiveTo investigate the risk factors and prognosis of non-spontaneously regressing immunodeficiency-associated lymphoproliferative disorders (LPDs) after methotrexate (MTX) discontinuation in patients with rheumatoid arthritis (RA). MethodsWe retrospectively reviewed medical records of 38 patients with MTX-associated LPD and compared the characteristics of those with and without spontaneous regression (SR) of LPDs (SR versus non-SR groups: n = 22 versus 16) and of survivors and non-survivors in the non-SR group (n = 5 deaths). ResultsThe SR and non-SR groups were comparable regarding age, sex, RA duration and activity, MTX use duration and dose, LPD stage and histological characteristics (lymphoma types and Epstein–Barr encoding region in situ hybridisation positivity). However, the non-SR group had significantly higher lactate dehydrogenase (LDH) levels at LPD diagnosis and lower lymphocyte recovery 1 month after MTX withdrawal. Multivariate analysis revealed poor lymphocyte recovery 1 month after MTX withdrawal as a risk factor for non-SR (odds ratio: 7.12; p = 0.02). Log-rank test showed that elevated LDH levels (250 U/L) were significantly associated with death (p = 0.02). ConclusionsLack of lymphocyte recovery 1 month after MTX discontinuation was a risk factor for non-spontaneously regressive LPD. High LDH level was associated with death in these cases.
Wakatsuki et al. (Tue,) studied this question.