P1283: CIRCULATING IMMUNE CELLS IN CLASSICAL HODGKIN LYMPHOMA IN RELATION TO TUMOR BURDEN AND TREATMENT - T. A. Mulder; M. L. Andersson; K. Heimersson; I. Xagoraris; B. E. Wahlin; G. Rassidakis; L. Hansson; M. Palma (HemaSphere, 2022)