The causative organism was MP in 76 (73%) patients and CP in 28 (27%) patients and was identified by serological testing (positive IgM or elevated IgG) in 71 patients, positive PCR on respiratory samples in 33 patients (18 on bronchoalveolar lavage, 10 on naso-pharyngeal aspirate, 2 on tracheal aspirate and 4 on nasal swab) and by both diagnostic methods in 5 patients. Here, CD40LG is linked to hyperplastic polyp.