IHC - Human Melanoma Black 45 Test

Human Melanoma Black 45 (HMB-45) is an antibody used as an IHC reagent has often been labeled as a marker for melanoma, even though some benign lesions have been noted to show positive staining reactions with this reagent. In IHC assays, this HMB-45 reacts with melanoma cells, junctional nevus cells, and fetal melanocytes but generally not with completely melanized normal adult melanocytes or with intradermal nevus cells. Except some rare tumors showing evidence of melanogenesis (clear cell sarcoma, pigmented schwannoma) or tumors associated with tuberous sclerosis complex, HMB 45 is non-reactive with almost all non-melanoma malignancies. HMB-45 in sentinel lymph nodes is considered to have low false-positive results because of its good resolution and low background staining.

• It does not require any sorts of special preparation for the test.
• Take advice from your doctor before undergoing the test. Prior to the test he/she may advice you to stop taking certain medications depending on your condition.
• Drink enough water. Getting yourself dehydrated before the test is an added advantage in any blood test as it nourishes the veins.
• Wearing tight full sleeve clothes are not advisable because usually the phlebotomist collect the blood sample from your arm and tight sleeves may cause difficulty in getting the required superficial vein.

The use of immunohistochemistry (IHC) with melanocytic marker such as HMB45 increases the detection rate of the spread of cancer from its original location to other parts (micrometastasis). Helps to identify conjunctival and choroidal melanomas as these expressed the HMB-45 in more than 95% of the cases. HMB 45 antibody gives a qualitative assessment of malignant melanoma. The test helps in marking the progression of skin cancer.

Blood sample is taken through following process. A band is wrapped around the arm at about 3-4 inches above the superficial vein that lies within the elbow pit The site is then cleaned using alcohol, A need is then penetrated to the vein so as to collect required amount of blood sample by pulling the plunger of the syringe attached to the needle. The wrap band is removed and bandage is applied to stop the bleeding. The blood is immediately transferred into an anti-coagulant container. The syringe and the needle are the disposed under hygienic conditions.