Laboratory Medicine
Test Directory / C4 Complement
C4 Complement
Brown clotted serum, gel barrier or lithium heparin
| Test | C4 Complement |
|---|---|
| Common Abbreviations | C4, C4C |
| Profile | NA |
| Tube type | Brown clotted serum, gel barrier or lithium heparin |
| Clinical Indication | Activation or consumption of complement occurs in a number of disorders, particularly those involving immune complex deposition e.g. SLE, mixed cryoglobulinaemia and some forms of vasculitis, however this may be compensated for in part by the synthesis of acute phase reactants. C3 comprises about 30% of the total plasma concentration of complement components and is consumed by activation of both the classical and alternative pathways. C4 levels fall only as a consequence of classical pathway activation, therefore if hypocomplementemia is present, measurement of both C3 and C4 can determine whether the classical or alternative pathway has been activated. |
| Specimen Type | Blood |
| Sample type | Serum |
| Minimum Volume | 0.5mL If requesting more than 10 tests please send an additional brown clotted serum sample. |
| Special Precautions | No special requirements |
| Stability | 2 days at 15-25°C and 8 Days at 2-8°C |
| Turnaround Time | Inpatient: 4 days Outpatient/ GP: 4 days |
| Laboratory | Scarborough |
| Reference Interval | 0.1 - 0.4 g/L |
| Limitations | The assay should not be performed on grossly haemolysed or lipaemic samples. Samples with extremely abnormal optical characteristics, especially turbidity may produce atypical results. |
| Notes |
