Pneumocystis Jirovecii Gene Polymsorphim Is Associated With Clinical Prognosis In Patients With AIDS-associated Pneumocystis Pneumonia

Aim:In this study,we study with AIDS Pneumocystis Pneumonias(AIDS-PCP)patients and analyze relationship between gene polymoiphisms of Pneumocystis jirovecii(PJ)with clinical outcomes.Methods:This study included 160 AIDS-PCP patients who were hospitalized at the First Affiliated Hospital,College of Medicine,Zhejiang University in 2016-2018.According to the principle of informed consent,80 blood samples and 80 saliva samples were taken from patients when they were admitted to the hospital.According to the results of the nest PCR by using the blood samples and the mitochondrial large subunit rRNA(mtLSU rRNA)gene primer,we divided the 80 patients into PJ-DNA positive and PJ-DNA negative groups and analyze the survival difference between the two groups by Kaplan-Meier method.The quantitative PCR(qPCR)was used for mtLSU rRNA gene in the PJ-DNA positive groups and analyze the level of PJ-DNA between survivors and non-survivors.Genotyping mtLSU rRNA gene and analyze the difference in mortality between different genotypes.According to the survival condition after treatment,80 patients with blood collection were divided into survival group and non-survival group.The basic information and clinical data of the two groups were analyzed.Logistic regression was used to analyze the independent risk factors of death.In addition,the saliva specimens were subjected to PCR amplification and sequence analysis for respectively mtLSU rRNA,dihydrofolate reductase(DHFR),dihydropteroate synthase(DHPS),cytochrome b(CYB),and superoxide dismutase(SOD)genes.The gene polymorphisms and the relationship between polymorphism combinations and clinical outcomes were analyzed.Results:The survival rate of the PJ-DNA positive group(n=20)was significantly lower than that of the PJ-DNA negative group(n=60)(P≤0.001).In PJ-DNA positive group,the number of copies in the non-survival group(n=11)was significantly higher than that in the surviving group(n=9)(P=0.006).PJ-DNA positive patients with mtLSU rRNA genotype 1(8/9)had a higher mortality rate than those who with genotype 3(1/9)(P=0.003).In logistic analysis,we found that LDH(OR=1.303,95%CI:1.063-1.597,P=0.011),Pa02(OR=1.035,95%CI:1.001.069,P=0.042),ALB(OR=0.997,95%CI:0.995-0.999,P=0.01),and PJ-DNA positive in blood(OR=62.474,95%CI:7.249-538.460,P≤0.001)were independent predictors of death.In 80 saliva samples,30 cases of mtLSU rRNA gene,26 cases of CYB gene,18 cases of SOD,DHFR and DHPS genes were successfully amplified and sequenced The results showed that mtLSU rRNA,CYB,SOD gene had more gene polymorphisms.The mutation rate of DHFR and DHPS gene is low.The gene polymorphism combination of mt85C,CYB1,SOD1,DHFR312T(n=4;22.22%)is more common.The gene polymorphism combination of mt85T,CYB1,SOD1,DHFR312T may be associated with poor clinical outcomes.Conclusion:The high PJ-DNA copy number in plasma and mtLSU rRNA genotype 1 are associated with higher mortality,combination of mt85T,CYB1,SOD1,DHFR312T gene is associated with poor prognosis.