Which of the following pattern of antibodies is seen most commonly?
**Core Concept**
The question is testing the understanding of the patterns of antibodies seen in various autoimmune conditions. The correct answer choice will be the most common pattern of antibodies observed in these conditions.
**Why the Correct Answer is Right**
The most common pattern of antibodies seen is the **IgM/IgG** pattern. This is because IgM antibodies are the first line of defense and are produced in response to infections and autoimmune conditions. IgG antibodies are the most abundant type of antibody and provide long-term immunity. In many autoimmune conditions, such as rheumatoid arthritis and systemic lupus erythematosus, both IgM and IgG antibodies are produced against specific antigens.
**Why Each Wrong Option is Incorrect**
* **Option A:** IgA/IgG is not a common pattern of antibodies in autoimmune conditions. IgA is primarily involved in mucosal immunity and is not typically associated with autoimmune diseases.
* **Option B:** IgE/IgG is not a common pattern of antibodies in autoimmune conditions. IgE is primarily involved in allergic reactions and is not typically associated with autoimmune diseases.
* **Option C:** IgM/IgA is not a common pattern of antibodies in autoimmune conditions. While IgM is involved in autoimmune diseases, IgA is not typically associated with these conditions.
**Clinical Pearl / High-Yield Fact**
It's essential to remember that the pattern of antibodies can provide clues about the underlying autoimmune condition. For example, a patient with rheumatoid arthritis may have IgM/IgG antibodies against the rheumatoid factor, while a patient with systemic lupus erythematosus may have IgM/IgG antibodies against various nuclear and cytoplasmic antigens.
**Correct Answer:** C. IgM/IgG.