Investigating synovial trace elements as diagnostic markers in acute septic arthritis: an exploratory study

Area of Science:

• Rheumatology
• Clinical Chemistry
• Biometals

Background:

• Acute arthritis diagnosis is challenging, often requiring differentiation between infectious and non-infectious causes.
• Traditional methods like cytology and microbiology may not always provide clear etiological insights.
• Synovial fluid metal concentration variations are hypothesized to aid in diagnosis.

Purpose of the Study:

• To evaluate the diagnostic value of metal concentrations in synovial fluid for acute arthritis.
• To determine if metallomic profiling can assist in identifying the cause of acute joint inflammation.

Main Methods:

• Retrospective analysis of synovial fluid samples from the SYNOLACTATE-PLUS cohort.
• Metal quantification using Inductively Coupled Plasma Mass Spectrometry (ICP-MS).
• Diagnostic performance assessed via logistic regression and Area Under the Curve (AUC).

Main Results:

• Significantly higher iron and zinc levels were observed in septic arthritis compared to non-septic arthritis.
• Elevated copper and manganese, and decreased strontium levels were also noted in septic cases.
• High AUC values (0.835 for iron, 0.825 for zinc) indicate strong diagnostic potential.

Conclusions:

• Synovial metallomic profiling, focusing on iron, zinc, copper, manganese, and strontium, may enhance etiological diagnosis of acute arthritis.
• These findings suggest a potential new diagnostic approach for joint inflammation.
• Prospective validation is necessary to confirm the clinical utility of this method.