PATHCHAT Edition
Published: 2024
Please contact your local Ampath pathologist for more information.
Metal Allergy Testing at Ampath
✅ Exclusive Testing in South Africa
- Ampath is the only private laboratory in South Africa that offers testing for metal hypersensitivity.
- Testing is conducted at the Cellular Immunology Laboratory.
📌 Metal allergy testing helps diagnose hypersensitivity before and after surgical procedures involving implants.
What is the Test for Metal Allergy?
✅ Lymphocyte Proliferation Test (LPT)
- Measures the immune system’s reaction to metals.
- Metals to be tested should be specified by the requesting clinician.
- A dedicated metal allergy request form is available from Ampath representatives.
📌 LPT identifies delayed-type hypersensitivity reactions caused by metal exposure.
List of Metals and Metal Alloys Tested
✅ Metals Included in the Test
✔ Common Metals & Alloys
- Aluminium
- Chromium
- Cobalt
- Copper
- Iron
- Lead
- Manganese
- Nickel
- Palladium
- Platinum
- Silver
- Stainless steel alloy traces
- Tin
- Titanium alloy traces
- Zinc
✔ Rare & Industrial Metals
- Arsenic
- Barium
- Beryllium
- Cadmium
- Gallium
- Indium
- Lanthanum
- Mercury (ethyl, inorganic, methyl, phenyl)
- Molybdenum
- Ruthenium
- Thimerosal
- Titanium IV dioxide
- Titanium IV oxysulfate
- Vanadium
- Zirconium
📌 This test can detect allergies to multiple metals commonly found in medical implants, jewellery, and industrial materials.
Why is Metal Allergy Testing Clinically Relevant?
✅ The Growing Need for Metal Hypersensitivity Testing
- Increasing exposure to metals from the environment and medical devices raises the risk of hypersensitivity.
- Chronic low-level exposure may trigger allergic reactions over time.
- Testing before surgery helps prevent adverse reactions to metal implants, reducing revision surgeries.
📌 Identifying metal allergies before surgery can prevent complications and improve patient management.
Who Should Get Tested for Metal Allergy?
✅ Recommended for Patients Undergoing Implant Procedures
- Orthopaedic implants (e.g., joint replacements).
- Dental implants and fillings.
- Gynaecological implants.
- Cardiology devices (e.g., pacemakers, stents).
✅ High-Risk Patients for Metal Allergy
- History of metal allergies (e.g., reactions to nickel-containing jewellery).
- Previous adverse reactions to implanted medical devices.
✅ Patients Experiencing Symptoms After Surgery
✔ Cutaneous Symptoms
- Oedema
- Erythema
- Urticaria
- Vasculitis
- Dermatitis resistant to treatment
✔ Regional Symptoms
- Delayed wound healing
- Muscle necrosis
- Chronic pain
- Arthralgia
- Osteolysis
- Prosthetic device loosening/failure
📌 Early identification of metal hypersensitivity prevents complications and unnecessary surgical interventions.
Special Sampling Instructions
✅ Key Considerations for Testing
- Metal allergy is a Type IV (delayed) hypersensitivity reaction.
- Caused by the activation and proliferation of memory T-lymphocytes.
- Samples must be processed within 24 hours to maintain cell stability.
✅ Sampling Guidelines
✔ Collection Timing
- Blood samples must be drawn Sundays to Thursdays only.
- Controlled sampling prevents false-negative results.
✔ Blood Sample Requirements
- 4–8 citrate tubes (depending on the number of metals tested).
- Samples must be kept at room temperature.
- Samples must remain uncentrifuged.
📌 Strict handling protocols ensure accurate and reliable test results.
Understanding the Test Results
✅ How the Lymphocyte Proliferation Test (LPT) Works
- Measures the background immune response (without metal exposure).
- Compares this to the immune response after adding metal allergens.
- Results are expressed as a stimulation index:
- A value of ≥4 is considered positive for metal hypersensitivity.
📌 Positive results indicate a heightened immune response to specific metals, confirming hypersensitivity.
Turnaround Time and Contact Information
✅ Turnaround Time
- Testing begins within 24 hours of sample collection.
- Full results and interpretation take up to 10 days.
✅ For Queries and Test Requests
- Ampath Cellular Immunology Laboratory: 012 678 0530
- Visit: ampath.co.za
📌 Timely metal allergy testing can guide treatment decisions and improve patient safety.