Challenges in biomarker research in haemophilic arthropathy

Deciphering the circulating microRNA signature of hemophilic arthropathy

BACKGROUND

Haemophilic arthropathy (HArt) is a serious complication in patients with hemophilia. Early diagnosis and treatment are essential to minimise the development of HArt. The use of biomarkers may improve early diagnosis of HArt. Circulating microRNAs (miRNAs) are small, non-coding RNAsthat regulate gene expression, and are being investigated as promising biomarkers due to their role in joint and bone metabolism.

AIMS

To investigate differential expression of miRNAs and their relationship to arthropathy in patients with hemophilia A.

METHODS

miRNA expression was examined in a pilot study followed by a validation study (100 hemophilia A patients with [n = 83] and without HArt [n = 17], 14 controls). Differential miRNA expression was investigated using real-time quantitative PCR.

RESULTS

The pilot study identified 2 miRNAs differentially expressed in patients with Hart (Pettersson score ≥ 1), after adjusting for the false discovery rate (FDR). The validation study evaluated these 2 miRNAs. The results demonstrated that two miRNAs (miR- 208a-3p and 524-3p) were significantly underexpressed in plasma of patients with HArt compared to patients without arthropathy, with FDR <0.05 (Fig. 1). In addition, 3 miRNAs (130a-3p, miR- and 506-3p) were significantly underexpressed in patients with moderate HArt (Pettersson score 4 to 7).

CONCLUSIONS

In this proof of concept study we identified a signature of 5 circulating miRNAs associated with Hart with potential as diagnosis tools for HArt. These miRNAs are potential negative regulators of gene expression, suggesting their activity in HArt by interfering with osteoblastic (miR- 208a-3p) and osteoclastic (miR-506-3p) differentiation to impair bone mineralization and remodeling processes, or regulating chondrogenesis (miR-335-5p). miRNAs associated with earlier stages of HArt will be further investigated in a sub-study of the prospective clinical trial PROVE, which will investigate the effects of long-term prophylaxis with simoctocog alfa versus emicizumab in adults with hemophilia A.

Stromal cell-derived factor 1 alpha (SDF-1alfa) and cartilage oligomeric matrix protein (COMP): Two potential signature biomarkers of radiological detectable hemophilic arthropathy

INTRODUCTION

Hemophilia is a rare constitutional bleeding disorder due to a deficiency in Factor VIII or Factor IX. Recurrent hemarthroses, one of the major complications of the disease, lead to hemophilic arthropathy, a disabling condition that requires early diagnosis. Traditionally, clinical examination and plain film radiography have been used to diagnose hemophilic arthropathy. Magnetic resonance imaging (MRI) and ultrasound can be more useful for diagnosing soft-tissue changes. However, but each of these methods has limitations and diagnosis of arthropathy can be delayed.

AIM

The aim of this project was to assess plasmatic biomolecules indicative of osteo-cartilaginous damage in patients with hemophilia with or without known arthropathy, in order to improve the diagnosis of this major complication of the disease.

METHODS

In this monocentric retrospective study, 40 patients with hemophilia A or B, for whom a plasma sample was available, provided informed consent for further analyses (multiplex immunoassays and ELISA) and collection of relevant clinical information in their medical files. Correlations were sought for between biomarkers of interest and the severity of joint lesions assessed according to Pettersson's radiologic score.

RESULTS

Two biomarkers were identified, respectively SDF-1α and COMP. Their plasmatic levels were significantly increased in patients with arthropathy compared to controls and patients without arthropathy. These values correlated significantly with the Pettersson score in patients under regular prophylaxis.

CONCLUSION

Two plasma biomarkers have been identified that could help assess the presence and severity of hemophilic arthropathy.

Poor correlation between biomarkers and MRI-detected joint damage in a cross-sectional study of persons with nonsevere hemophilia A (DYNAMO study)

BACKGROUND

Persons with nonsevere hemophilia A (NSHA) experience less frequent joint bleeding than persons with severe hemophilia A, but may still develop joint damage. Biomarkers of cartilage and synovial remodeling can reflect ongoing pathologic processes that may precede or coincide with damage on joint imaging. If so, biomarkers may be an important diagnostic tool for joint damage in NSHA.

OBJECTIVE

To assess the correlation between biomarkers and MRI-detected joint damage in persons with NSHA.

METHODS

In a cross-sectional study, men with NSHA (factor VIII [FVIII], 2-35 IU/dL) were included. Participants underwent magnetic resonance imaging of elbows, knees, and ankles and blood and urine sampling for biomarker analysis on a single visit. The following biomarker(s) were analyzed in urine: CTX-II or serum: cartilage oligomeric matrix protein, chondroitin sulfate 846, vascular cell adhesion molecule 1, osteopontin (OPN), neo-epitope of MMP -mediated degradation of type II collagen, N-terminal propeptide of type II collagen, collagen type IV M, and propetide of type IV collagen. Spearman's rank correlations were calculated between these biomarkers and the total International Prophylaxis Study group (IPSG) score, soft-tissue subscore, and osteochondral subscore.

RESULTS

In total, 48 persons with NSHA were included. Median age was 43 years (range, 24-55 years) and median FVIII was 10 IU/dL (IQR, 4-16 IU/dL). The median IPSG score was 4 (IQR, 2-9). Median IPSG soft-tissue subscores were 3 (IQR, 2-4) and osteochondral subscores were 0 (IQR, 0-4). No strong correlations were found between the studied biomarkers, total IPSG score, subsequent soft-tissue, and osteochondral subscores.

CONCLUSIONS

In this study, selected biomarkers indicative of different aspects of hemophilic arthropathy showed no consistent correlation with IPSG scores. This suggests that systemically measured biomarkers are currently not suitable for identifying milder joint damage in NSHA, as observed on magnetic resonance imaging.

Ferroptosis: a new target for iron overload-induced hemophilic arthropathy synovitis

Iron deposition is closely related to developing haemophilic arthropathy (HA). Studying the relationship between ferroptosis signal expression and iron overload in HA synovium facilitates understanding the pathogenesis of joint synovial hyperplasia in bloodborne arthritis and the development of new protective methods. The knee synovium was collected from HA and osteoarthritis (OA) patients, and pathological changes were analysed by HE and Prussian blue staining. Ferroptosis phenotypes were examined by immunohistochemistry and western blotting. Moreover, ferric ammonium citrate (FAC)-induced was used to construct an in vitro iron overload model to investigate the relationship between iron overload and ferroptosis in synovial fibroblasts (FLS). Furthermore, the factors influencing ferroptosis in FLS were explored. Iron deposition, cell proliferation, and vascular proliferation in the synovium of HA were more obvious. Ferroptosis in HA synovium appears to inhibit. FLS ferroptosis increased with iron accumulation, malondialdehyde (MDA) in cells, and glutathione (GSH) depletion. TNF-α plays a protective role in this process. Blocking the action of TNF-α and inducing ferroptosis significantly reduced synovial proliferation. TNF-α inhibitors combined with a ferroptosis inducer may be a new therapeutic method for HA synovitis.