CRP and Recurrent lower respiratory tract infections: However, concurrent information on causative agents and CRP levels, perhaps as a combination test with other biomarkers, for suspected lower respiratory tract infection might be useful for improved decision making when CRP levels are moderately raised.13, 41, 42 Finally, the findings also suggested reduced antibiotic prescribing in patients with chronic obstructive pulmonary disease, but the group size was too small to allow for firm conclusions.