Background
Interstitial lung disease (ILD) is the most frequent type of organ involvement and the main cause of death in systemic sclerosis (SSc). The trigger of fibrosis is an immune mediated alveolitis, thus in the last years, several immunosuppressant drugs have been put to the test, mostly cyclophosphamide (CYC), azathioprine (AZA) and mycophenolate mofetil (MMF).
Therefore, also in the Rheumatology Unit of Padua University, in recent years have been treated in with immunosuppressive therapy.
Aim
The aim of our study was to evaluate the efficacy of MMF as a first-line drug on pulmonary function in SSc-related ILD patients and compare them to a historical group of SSc patients treated with CYC followed by AZA.
Moreover, it has been assessed the safety of each immunosuppressant drugs.
Methods
Eighteen patients with SSc-related ILD have been investigated and treated with MMF as first-line therapy for two years.
Fifteen patients, instead have been treated one year with CYC and for and with AZA for the second years.
The two groups of patients have been evaluated at baseline, and then after 12 and 24 months of therapy.
The evaluation parameters were: pulmonary function tests (FVC and DLCO), HRCT score and NYHA class.
The comparison between the two groups was assessed using Pearson’s chi-square test, student t test and Wilcoxon signed rank test as statistical approaches.
Results
At baseline, patients characteristics appeared homogeneous between the two groups and non-statistically significant increase of FVC was observed in both groups at month 12 and month 24.
In the group treated with MMF no patient has deteriorated in NYHA functional class, respiratory tests showed an average stability pulmonary function and no patient has progressed in the TC score.
In the control group, treated sequentially with CYC and AZA, has no been shown significant difference in NYHA class, respiratory tests, or in score TC.
Comparing the two groups, no resounding significant difference has been highlighted. for the evaluated clinical parameters, showing similar efficacy of MMF compared to a pattern of traditional immunosuppressive therapy.
In the group treated with MMF no patients reported adverse events than can cause discontinuation of treatment, while in the control group, 2 patients had to interrupt the CYC for leukopenia, and 5 had suspended AZA, 2 for hepatotoxicity and 3 for leukopenia.
The difference between the two groups respect to adverse events was statistically significant in favor of MMF (p = 0.0046).
Conclusions
The data of our study suggest that the immunosuppressive therapy with MMF administered for a period of two years has led to a stabilization of ILD in a cohort of SSc patients, as shown by respiratory test, the HRCT score, and functional class NYHA. Similar results have been observed in another group cohort of patients treated sequentially for two years with CYC and AZA.
Besides, MMF treated group presented a significant decrease of side effects, compared to the group treated with CYC and AZA
