Association of NLRP3, Caspase-1 and TLR4 mRNA with severity and prognosis of patients with severe MRSA pneumonia

OBJECTIVE To study the relationship of nucleotide-binding oligomerization domain-like receptor protein 3(NLRP3), cysteine protease 1(Caspase-1) and Toll-like receptor 4(TLR4) messenger ribonucleic acid (mRNA) with the severity and prognosis of patients with severe methicillin-resistant Staphylococcus aureus (MRSA) pneumonia.

METHODS One hundred and three patients with MRSA-infected pneumonia admitted to Shengjing Hospital affiliated to China Medical University from Jun. 2020 to Jun. 2023 were selected as the MRSA-infected group, and 112 patients with conventional-infected pneumonia admitted during the same period were selected as the non-MRSA-infected group. The levels of NLRP3 mRNA, Caspase-1 mRNA and TLR4 mRNA in peripheral blood of the two groups were tested, and their levels in peripheral blood of patients with pneumonia infected by MRSA with different severity and different prognosis were compared. The predictive values of NLRP3 mRNA, Caspase-1 mRNA and TLR4 mRNA were analyzed by receiver operating characteristic (ROC) curve.

RESULTS The peripheral blood NLRP3 mRNA, Caspase-1 mRNA, and TLR4 mRNA levels in the MRSA-infected group were (1.53±0.29), (2.04 ± 0.49) and (1.04 ± 0.32), higher than those in the non-MRSA-infected group (P < 0.05), respectively. The mRNA levels of NLRP3, Caspase-1, and TLR4 in peripheral blood of the severe MRSA-infected group were higher than those of the non-severe MRSA-infected group (P < 0.05). The peripheral blood NLRP3 mRNA, Caspase-1 mRNA, and TLR4 mRNA levels in the poor prognosis group were (2.47±0.72), (2.84±0.90) and (1.94±0.63), higher than those in the good prognosis group (P < 0.05), respectively. The area under the curve (AUC) of the combination of peripheral blood NLRP3 mRNA, Caspase-1 mRNA and TLR4 mRNA to predict the prognosis of MRSA-infected patients with severe pneumonia was 0.853, which was higher than that of the three indexes alone (P < 0.05).

CONCLUSION Peripheral blood NLRP3 mRNA, Caspase-1 mRNA and TLR4 mRNA levels are elevated with the onset and progress of disease in patients with MRSA-infected pneumonia, and the combination of the three indexes has a high predictive value for the prognosis of patients with MRSA-infected severe pneumonia.