Test Directory
Soluble Complement 5b-9 (sC5b-9)
Justification
Elevations in soluble Complement 5b-9 (sC5b-9) have been associated with increased activation of the alternative complement pathway. Increased complement activation may be seen with aHUS and other TMAs, and may be a sensitive early predictor of the development of transplant associated TMA. In a cohort of 67 pediatric patients who had an allogeneic HSCT, an increase in sC5b-9 concentration from baseline had 100% sensitivity and 53% specificity for TA-TMA.
STAT: < 24 hours (7 days a week)
ELISA
Draw Tube: Purple Top
Sample Type: EDTA Plasma
Specimen Requirements
| Sample Type | Volume Required | Minimum Volume | Stability | |
|---|---|---|---|---|
| PREFERRED | EDTA Plasma | 1mL | 0.5mL | Frozen (-20C): 72 hours Frozen (-80C): 6 months |
| ALTERNATIVE | - | - | - | - |
| REJECTION CRITERIA | Thawed in transit if shipped frozen, refrozen, clotted sample |
| SPECIAL INSTRUCTIONS | Process and freeze samples within two hours of collection. Transport under dry ice. |
General Information
| METHODOLOGY | ELISA |
| STAT TAT | < 24 hours (7 days a week) |
| STAT TAT Performance | > 90% of results released in 21.2 hours 7 days a week |
| ROUTINE TAT | < 48 hours (Monday-Friday) |
| ALTERNATIVE NAMES | soluble C5b-9, sC5b-9, soluble MAC, sMAC, membrane attack complex, TCC, terminal complement, complement activation |
| DESCRIPTION | Chromogenic ELISA for the quantitative detection of soluble complement 5b-9, also known as the soluble membrane attack complex (sMAC). |
| LIMITATIONS | - |
| NORMAL RANGE | < 250 ng/mL |
| ASSOCIATED TESTING | - |
| REFERENCES | Bomback AS et al. Clin J Am Soc Nephrol. 2012 May;7(5):748-56. Nicolas C et al. Pediatr Nephrol. 2014;29(1):85. Mezö B, Horváth O, et al. Validation of Early Increase in Complement Activation Marker sC5b-9 as a Predictive Biomarker for the Development of Thrombotic Microangiopathy After Stem Cell Transplantation. Front. Med. 2020 Oct 6; 7:569291. doi: 10.3389/fmed.2020.569291 Horváth O, Kállay K, et al. Early Increase in Complement Terminal Pathway Activation Marker sC5b-9 Is Predictive for the Development of Thrombotic Microangiopathy after Stem Cell Transplantation. Biol Blood Marrow Transplant 2018 May; 24(5):989-996. |
| SAMPLE REPORT | Upon request |
| NEW YORK STATE APPROVED | Yes |
Test Codes
| ORDER CODE | P3364 |
| CPT CODE | 86160 |
| LOINC CODE | 93244-2 |