Idiopathic thrombocytopenic purpura in a patient with IgG4-related disease

Incidence and risk factors of systemic lupus erythematosus in patients with primary immune thrombocytopenia: a systematic review and meta-analysis

Background

Immune disorders and autoantibodies has been noted in both primary immune thrombocytopenia (ITP) and systemic lupus erythematosus (SLE). Whether the two disorders are correlated is unclear. The lack of evidence on the incidence of and risk factors for SLE in primary ITP patients poses a challenge for prediction in clinical practice. Therefore, we conducted this study.

Methods

The protocol was registered with PROSPERO (CRD42023403665). Web of Science, Cochrane, PubMed, and EMBASE were searched for articles published from inception to 30 September 2023 on patients who were first diagnosed with primary ITP and subsequently developed into SLE. Furthermore, the risk factors were analyzed. Study quality was estimated using the Newcastle-Ottawa Scale. The statistical process was implemented using the R language.

Results

This systematic review included eight articles. The incidence of SLE during the follow-up after ITP diagnosis was 2.7% (95% CI [1.3-4.4%]), with an incidence of 4.6% (95% CI [1.6-8.6%]) in females and 0 (95% CI [0.00-0.4%]) in males. Older age (OR = 6.31; 95% CI [1.11-34.91]), positive antinuclear antibody (ANA) (OR = 6.64; 95% CI [1.40-31.50]), hypocomplementemia (OR = 8.33; 95% CI [1.62-42.91]), chronic ITP (OR = 24.67; 95% CI [3.14-100.00]), organ bleeding (OR = 13.67; 95% CI [2.44-76.69]), and female (OR = 20.50; 95% CI [4.94-84.90]) were risk factors for subsequent SLE in ITP patients.

Conclusion

Patients with primary ITP are at higher risk of SLE. Specific follow-up and prevention strategies should be tailored especially for older females with positive ANA, hypocomplementemia, or chronic ITP. In subsequent studies, we need to further investigate the risk factors and try to construct corresponding risk prediction models to develop specific prediction strategies for SLE.

Risk of systemic lupus erythematosus in patients with idiopathic thrombocytopenic purpura: a population-based cohort study

BACKGROUND

Idiopathic thrombocytopenic purpura (ITP) may play a role in early-stage systemic lupus erythematosus (SLE). The incidence of SLE in patients with ITP and the potential relationship between them is still unclear. This study was performed to provide epidemiological evidence regarding the relationship between ITP and SLE occurrence.

METHODS

In this population-based retrospective cohort study, the risk of SLE was analysed in a cohort of patients newly diagnosed with ITP between 2000 and 2013. Controls were selected at a 1:2 ratio through propensity score matching (PSM) using the greedy algorithm. The Cox proportional hazard model was used to analyse the association between ITP and SLE incidence. There were four different Cox regression models, and the sensitivity analyses were implemented to evaluate the HR of SLE after exposure with ITP.

RESULTS

In the age-matched and sex-matched ITP and non-ITP cohort, the average follow-up time was about 80 months in this study. There were 34 (4.70%) and 27 (0.19%) incident cases of SLE in ITP and non-ITP group. The incidence rates were 62.0 (95% CI 44.3 to 86.8) and 2.10 (95% CI 1.44 to 3.06), respectively. The adjusted HR of incidental SLE in the ITP group was 25.1 (95% CI 13.7 to 46.0). The other risk factors for SLE were female sex and Sjogren's syndrome. After PSM, the incidence rate and Kaplan-Meir curves of SLE were consistent with the results for the age-matched and sex-matched population, the HR 17.4 (95% CI 5.28 to 57.4) was estimated by conditional Cox model.

CONCLUSION

This cohort study demonstrated that patients with ITP have a higher risk of SLE. Clinically, patients with ITP should be monitored for incidental lupus.