Early response evaluation with [18F]fluordeoxyglucose (FDG) positron emission tomography after 2 cycles of chemotherapy (interim PET) has been indicated as the strongest predictor for outcome in classical Hodgkin lymphoma (HL). We studied the prognostic role of the number of tumorâinfiltrating CD68+ cells and of the plasma levels of TARC (thymus and activationâregulated chemokine) in the context of interim PET in 102 patients with classical HL treated with Adriamycin, Bleomycin, Vinblastine, Dacarbazine (ABVD). After 2 ABVD cycles, interim PET according to Deauville criteria was negative (score 0â3) in 85 patients and positive (score 4â5) in 15 patients (2 patients technically not evaluable). TARC levels were elevated in 89% of patients at diagnosis, and decreased after 2 cycles in 82% of patients. Persistently elevated TARC levels in 18% of patients were significantly associated with a positive PET result (PÂ =Â 0.007). Strong predictors for progressionâfree survival (PFS) were a negative interim PET (85% vs. 28%, PÂ <Â 0.0001) and CD68+ cell counts <5% (89% vs. 67%, PÂ =Â 0.006), while TARC levels at diagnosis and at interim evaluation had no prognostic role. In multivariate analysis, interim PET, CD68+ cell counts and presence of Bâsymptoms were independently associated with PFS. We conclude that although TARC levels are a biomarker for early response evaluation, they cannot substitute for interim PET as outcome predictor in HL. The evaluation of CD68 counts and Bâsymptoms at diagnosis may help to identify lowârisk patients regardless positive interim PET.