Abstract
Objective
To investigate the role of parameters of iron metabolism in systemic lupus erythematosus (SLE) patients with pulmonary arterial hypertension (PAH).
Method
This was a prospective observational study recruiting patients diagnosed with systemic lupus erythematosus-associated pulmonary arterial hypertension (SLE-PAH). Patients with other factors that might lead to PAH were excluded from the study. All patients were assessed for PAH every 1–3 months and were followed up for 6 months. The primary outcome was considered improved if the grade of risk stratification declined at the endpoint; otherwise, it was considered unimproved.
Results
In total, 29 patients with SLE-PAH were included in this study. The mean of serum ferritin was higher than normal, and total iron binding capacity (TIBC) decreased in 48% of patients. Correlation analyses showed that serum iron (SI) was negatively correlated with World Health Organization functional class (WHO-FC) (r = −0.409, p = 0.028), and positively correlated with Six-Minute Walk Test distance (6MWD) (r = 0.427, p = 0.021) and tricuspid annular plane systolic excursion (TAPSE) (r = 0.388, p = 0.037). Primary outcomes improved in 12 patients at the endpoint, and univariate logistic regression analyses indicated that TIBC was associated with improved primary outcomes in patients with SLE-PAH (odds ratio 12.00, 95% confidence interval 1.90–75.72).
Conclusion
SI was negatively correlated with WHO-FC, and positively correlated with 6MWD and TAPSE. Furthermore, TIBC was associated with improved outcomes of patients with SLE-PAH, which could be an independent predictor of prognosis. Further research is needed to verify the findings.
Acknowledgement
We would like to thank Zoe Zeng for her help with language editing.
Disclosure statement
No potential conflict of interest was reported by the authors.