CRP and polycythemia: PNS can manifest as hematologic (anemia, polycythemia, thrombocythemia, thrombocytosis), metabolic (hypercalcemia, hyperuricemia, hepatic dysfunction), immunologic (elevated C-reactive protein [CRP], erythrocyte sedimentation rate [ESR], neutrophil–lymphocyte ratio [NLR]), or constitutional (fever, weight loss, night sweats, hypertension) abnormalities.