ACID HEMOLYSIN (HAM TEST)
- Code
- 900.1765
- Name
- ACID HEMOLYSIN (HAM TEST)
- Category
- None
- Department
- Send-Out
- Start Date
- Expiration Date
- Synonyms
- Ham Test; Congenital Dyserythropoietic Anemia type II
- CPT Codes
- 85475
- Site
- SBMF
- Reference Test
- 44336
Specimen Information
- Type
Red top (serum) tube, AND Lavender top (whole blood) tube
*Collect Monday through Thursday only and not the day before a holiday*
- Volume
3.0 mL serum (separated from cells), AND 5.0 mL whole blood (EDTA)
- Transport Info
Red top: Centrifuge and immediately transfer serum to a separate plastic tube
Room TemperatureLavendar top: Whole blood
Room Temperature*Specimens should be received at ARUP Laboratories within 24 hours of collection and testing must be performed within 48 hours of collection*
- Fasting Required?
- False
- Patient Instructions
- Reference Range
Negative
- Methodology
Visual Identification of Hemolysis
This is an Obsolete test; Flow cytometry is the preferred test for diagnosis of PNH
Clinical Significance
Confirmatory test for Paroxysmal Nocturnal Hemoglobinuria (PNH).
Acidified serum promotes complement binding to red blood cells and complement activation via the alternate pathway. Red blood cells that are hypersensitive to complement-mediated lysis, such as in the clonal disease paroxysmal nocturnal hemoglobinuria (PNH) and in type II congenital dyserythropoietic anemia (CDA) known as HEMPAS (hereditary erythroblast multinuclearity with a positive acid serum test), undergo lysis in ABO-compatible serum at pH 6.5-7.0. The Ham test is a confirmatory test for PNH if preceded by a positive sugar water (sucrose hemolysis) screening test. PNH cells may show lysis in either autologous or heterologous serum. The Ham test may also be applied in suspected cases of CDA, and when positive in this setting, is diagnostic of HEMPAS. Unlike PNH, HEMPAS does not have a positive sugar water test and does not show lysis in acidified autologous serum.