Which of the following methods can be used to obtain a definitive diagnosis of type I insulin-dependent diabetes ?

Options

A. Detecting the presence of islet cell antibodies
B. Performing an insulin receptor count
C. Testing for elevated blood sugar concentration
D. Screening individuals for obesity

Answer

To obtain a definitive diagnosis of type I insulin-dependent diabetes, follow these steps:

1. **Understand the Nature of Type I Diabetes**: Type I diabetes is an autoimmune condition where the immune system attacks and destroys the insulin-producing beta cells in the pancreas. This leads to an inability to produce insulin, resulting in high blood sugar levels.

2. **Recognize Symptoms**: Common symptoms of type I diabetes include excessive thirst, frequent urination, extreme fatigue, and blurred vision. However, these symptoms alone are not sufficient for a definitive diagnosis.

3. **Conduct Blood Tests**: Blood tests are essential for diagnosing diabetes. The most common tests include fasting blood glucose levels, random blood glucose tests, and HbA1c tests. However, these tests can indicate diabetes but do not confirm the type.

4. **Identify Autoantibodies**: For a definitive diagnosis of type I diabetes, it is crucial to identify specific autoantibodies that indicate an autoimmune response. The presence of these autoantibodies confirms that the diabetes is type I.

5. **Test for Specific Autoantibodies**: There are four main types of autoantibodies that can be tested:
- **Islet Cell Antibodies (ICA)**: These target the cytoplasmic proteins in beta cells.
- **Glutamic Acid Decarboxylase Antibodies (GAD65)**: These are directed against the enzyme glutamic acid decarboxylase.
- **Insulin Autoantibodies (IAA)**: These are antibodies against insulin itself.
- **IA-2 Antibodies (Insulinoma-Associated Protein 2)**: These target a protein tyrosine phosphatase.

6. **Confirm Diagnosis**: The presence of any of these autoantibodies, particularly islet cell antibodies, is indicative of type I diabetes. Therefore, testing for these autoantibodies provides a definitive diagnosis.