Optimized testing for C. trachomatis DNA in synovial fluid samples in clinical practice.

Area of Science:

• Molecular Biology
• Clinical Diagnostics
• Rheumatology

Background:

• Chlamydia trachomatis (C. tr.) detection in synovial fluid (SF) lacks a standardized polymerase chain reaction (PCR) assay for clinical use.
• Optimized molecular methods are needed to improve the diagnosis of C. tr. infections in patients with rheumatologic conditions.

Purpose of the Study:

• To evaluate and compare two optimized molecular biology methods for detecting C. tr. in SF samples.
• To determine the most sensitive method for C. tr. identification in SF from patients with various rheumatologic diseases.

Main Methods:

• Two DNA extraction methods, alkaline lysis and QIAEX II Gel Extraction Kit® + CTAB, were tested.
• A C. tr.-omp1-152 bp PCR assay was performed on SF samples from 329 patients with reactive arthritis, undifferentiated arthritis, rheumatoid arthritis, psoriatic arthritis, and osteoarthritis.

Main Results:

• Alkaline lysis combined with C. tr.-omp1-152 bp PCR detected C. tr. in 30% of reactive arthritis and 38% of undifferentiated arthritis patients.
• The QIAEX II Gel Extraction Kit® + CTAB method showed significantly lower detection rates (0% and 2%, respectively).
• Alkaline lysis also identified C. tr. in 17% of psoriatic arthritis patients; all rheumatoid arthritis and osteoarthritis samples were negative.

Conclusions:

• Alkaline lysis DNA extraction is the most sensitive method for detecting C. tr. in clinical SF samples when used with C. tr.-omp1-152 bp PCR.
• This optimized molecular approach enhances the diagnostic capability for C. tr. in rheumatologic conditions.