Invasive Pulmonary Fungal Infections In Patients With Connective Tissue Disease:A Retrospective Study

Background and purposeConnective tissue disease is a heterogeneous group of systemic autoimmune disease, including systemic lupus erythermatosus (SLE), rheumatoid arthritis (RA),polymyositis /dermatomyositi (PA/DM),systemic sclerosis (SSC),mixed connective tissue disease (MCTD),Jorgen’s syndrome (PSS) and several others. CTD is significantly related to immune mechanisms. Moreover, corticosteroids and immunosuppressive angents have been shown to be first-line treatment.Immunological mechanisms are suggested to play a role in the susceptibility to fugal infection in CTD patients. Moreover, drugs (mostly immunosuppressive or immunomodulating agents) used in the treatment of CTD give rise to a tendency to opportunistic infections. Hence infections have become a common complication in patients with CTD. Previous data showed that the occurrence rate of infection combined with SLE, RA, PA/DM was 40%-57%,17%,and 11.5% respectively. The mortality rate of PA/DM with infection was 27.7%, among which more than 50% of the patients died of fugal infection.In recent years, the proportion of fugal infections in CTD patients is increasing, Lung is one of the most commonly involved organs, and lung fugal infection tends to lead to disease exacerbation and even death. In addition, few attention has been directed at the study of invasive pulmonary fugal infections (IPFI) in CTD, and the factors related to CTD remain incompletely explored. Thus, we have selected CTD patients with pulmonary fugal infections in Qingdao University Affiliated Hospital from 2011 to 2013 and performed a retrospective analysis in order to clarify its etiological characteristics, clinical manifestations, predisposing factors and improving general awareness of CTD.Deep fungal infection has shown to have a significant effect on connective tissue disease (CTD) progression or even death. However, few cases of invasive pulmonary fungal infection (IFPI) are described in CTD and their related factors remains unclear.Objective:To estimate the prevalence and clinical features of IPFI in CTD patients and to uncover risk factors for IPFI associated CTD.Method:Patients with CTD who are hospitalized in a single institute from January 2011 to December 2013 were included.This was a retrospective study of 94 patients:47 with CTD combined with IPFI,and 47 patients without IPFI as control subjects.Results:The ratio of CTD patients with IPFI was 2.15%. Fungal isolation stratification:34 candidiasis (2.1%) and 1 cryptococcus (2.1%).Patients with CTD and IPFI had significantly higher WBC counts,ESR and CRP levels than that of controls (P<0.05).Maximum predisone dose≥30mg/d during infection,antibacterial drugs combined with interstitial pneumonia were risk factors for IPFI in CTD patients.Conclusion:IPFI is a rare form of fugal infection occurred in CTD patients especially in SLE.Clinically,the most common pathogen in China is Candida albicans.Predisposing factors include predisone dosage≥30mg/d during infection, prolonged use of antibacterial drugs and interstitial pneumonia.Given these data,it’s quite clear that more attention should be paid to these potential risk factors in CTD patients.Main Innovative PointsThe current research about invasive pulmonary fugal infection (IPFI) is mainly focused on hemopathy, renal disease especially after renal transplantation,etc.However, the factors related to CTD patients combined with IPFI still remain a mystery.Since the prolonged use of gulcocorticoid could lead to a increased chance of fungal infection in our study, we analysed glucocorticoid dosage with detailed statistics.we recorded the maximum dosage of glucocorticoid of CTD patients three months prior to IPFI and during IPFI. And the percentage of CTD patients whose predisolone dosage over 60mg/d prior to infection and whose dosage over 30mg/d during infection were recorded respectively.This may aid in the quantification of glucocorticoid in the treatment of CTD patients.