Diagnosis
Doctors may suspect amyloidosis based on patients' symptoms, findings on physical examination and sometimes family history. The diagnosis can be confirmed (or eliminated) by tests including:
- Tissue biopsy
- Genetic testing
- Imaging studies
Each type of amyloidosis requires specific tests and combinations.
At Abdali Hospital we conduct an initial clinical evaluation that includes:
- Blood and urine tests
- ECG and echocardiogram (ultrasound scan of the heart)
- Additional tests in some patients may include:
- Abdominal fat biopsy
- Bone marrow biopsy
- PYP scan of the heart
- Cardiac MRI
- Physician evaluation
- Specialist nurse consultation
The evaluation typically takes 1 -2 days, and hospital or hotel overnight accommodation can be arranged when necessary. We recommend that you bring a family member or friend with you if possible. There is a lot of information to take in and it will help to have someone with you to support you and help you.
The physician who evaluates you will explain your diagnosis and make recommendations regarding a suitable treatment plan. The specialist nurses explain and discuss practical nursing issues during the initial evaluation and are available afterwards for patients and relatives to contact with any questions that arise. Our approach to each patient with amyloidosis is tailored individually to the type of amyloid and to patients’ problems. Wherever possible, patients are discussed with the referring physician.
Tissue Biopsy
In this procedure, a small sample of tissue is removed from the body with a needle and examined in the laboratory. The tissue sample is often obtained from under the skin in the stomach area (abdominal fat biopsy). Alternatively, when ATTR amyloidosis is suspected, the biopsy sample may be taken from the heart, a nerve in the arm or leg, or the bowel, depending on the clinical features of the patient. In the laboratory, the tissue sample is examined using specific techniques to identify amyloid fibrils, including staining of the tissue with a dye called Congo red. Positive Congo red staining can identify amyloid. Then immunohistochemistry and proteomics testing can identify TTR fibrils and determine which type of ATTR amyloidosis is present, by distinguishing between ‘variant’ ATTR in hereditary ATTR amyloidosis and ‘wild-type’ ATTR in non-hereditary wild type ATTR amyloidosis.
Genetic Testing
What does genetic testing involve?
A blood sample is taken from the patient’s vein in a standard blood test. Specialized laboratory techniques are then used to examine the DNA from the blood cells to identify amyloidogenic mutations (abnormalities) in the TTR gene.
Where does genetic testing take place?
Currently the test in not available in Jordan. Samples are sent to a laboratory in Germany. The results are generally available after about 4 weeks
When is genetic testing used?
If ATTR amyloid fibrils are detected in tissue biopsy, then genetic testing can distinguish between hereditary and wild type ATTR amyloidosis. If a TTR gene mutation is detected, then the diagnosis is hereditary ATTR amyloidosis. If there is no TTR gene mutation, then the diagnosis is wild type ATTR amyloidosis (a non-hereditary condition). Symptoms and treatment are the same for these two conditions, but genetic testing can help us to learn more about the disease so that we may be better able to treat patients.
Genetic testing involves examination of the DNA from the patient’s cells. These techniques can identify amyloidogenic mutations (abnormalities) in the TTR gene. There are over 100 known mutations in the TTR gene, and different mutations lead to different types of disease. The precise mutation identified may provide information about the likely clinical course. For example, the most common mutation worldwide, the Val30Met mutation often leads to amyloid deposits just in the nerves, not in the heart. In contrast, the Val122lle mutation usually leads to amyloid deposits predominantly in the heart, and only occasionally affects the nerves. In wild-type ATTR amyloidosis, amyloid fibril analysis detects ‘wild-type’ ATTR protein and genetic testing will not detect any abnormalities in the TTR gene. Genetic testing in a healthy person without symptoms can provide information on whether the mutation is present but cannot predict whether the person will go on to develop amyloidosis.
