Overview:
RPR-Rapid Plasma Reagin Quantitative PanelIntroduction: The Rapid Plasma Reagin Quantitative (RPR Quantitative) Panel is a diagnostic tool designed to screen for syphilis using serum samples. In India, syphilis affects ~0.5-1 percent of antenatal women and higher in MSM/high-risk groups, with untreated cases causing congenital syphilis (~thousands/year) or neurosyphilis. High morbidity from under-testing in rural/low-SES pregnant women or symptomatic patients, limited labs, delayed penicillin leading to stillbirth or neurological sequelae. Per microbiology practices aligned with ICMR and National AIDS Control Organisation guidelines, the test employs immunoassay for RPR titre, VDRL, syphilis IgG/IgM, Treponema Ab, TPHA, and quantitative result over 1-2 days with high accuracy, valuable for staging and monitoring treatment response. This diagnostic falls under infection screening and targets pregnant women, high-risk groups, or patients with rash/genital ulcers, addressing accurate detection to guide benzathine penicillin. With elevated morbidity due to underdiagnosis, the test supports public health efforts by enabling precise syphilis confirmation and reducing congenital transmission. Its serum-based approach ensures reliable non-treponemal/treponemal assessment.
Other Names: RPR Quant Pnl.
FDA Status: FDA approved, CLIA certified for immunology, compliant with 2025 standards.
Historical Milestone: RPR quantitative standard for syphilis; in India, mandatory antenatal screening.
Purpose: The test assesses 7 parameters including RPR titre to guide syphilis screening, stage infection, inform penicillin therapy.
Test Parameters: 1. RPR Titre, 2. VDRL, 3. Syphilis IgG, 4. Syphilis IgM, 5. Treponema Ab, 6. TPHA, 7. Quantitative Result.
Pretest Condition: No fasting required; patients should have risk factors or symptoms.
Specimen: 3 mL serum in 1 SST, transported within specified times to maintain sample viability.
Sample Stability at Room Temperature: 8 hours with proper handling to preserve analyte integrity, ensuring reliable test performance.
Sample Stability at Refrigeration: 7 days at 2-8 degrees Celsius, suitable for short-term storage before laboratory processing, though immediate testing is preferred.
Sample Stability at Frozen: 6 months at -20 degrees Celsius, allowing long-term storage for retesting, though freezing may affect some analytes.
Medical History: Patients should provide details on rash, pregnancy, sexual history.
Consent: Written informed consent is required, detailing the test's purpose, potential risks of untreated syphilis including congenital defects, benefits of screening, and minimal discomfort from venipuncture.
Procedural Considerations: The test involves sample processing using immunoassay by trained personnel to ensure sterile technique, avoid hemolysis, and interpret results within 1-2 days using provided controls. Laboratories must maintain a controlled environment, adhere to quality assurance protocols.
Factors Affecting Result Accuracy: Delays beyond stability periods, improper storage conditions, hemolysis can affect results. Correlation with clinical evaluation or additional testing is recommended to confirm findings.
Clinical Significance: High RPR titre + positive treponemal Ab indicates active syphilis, necessitating specialist input.
Specialist Consultation: Dermatologists or infectious disease specialists should be consulted for management.
Additional Supporting Tests: TPHA confirmation, dark field microscopy for primary lesions.
Test Limitations: False positives in autoimmune diseases; comprehensive approach required.
References: Indian Journal of Dermatology 2024, STI Studies India 2023.
