What is the condition that is not typically associated with secondary systemic amyloidosis among the following: Tuberculosis (TB), Ulcerative colitis (UC), Psoriasis, Leprosy, Bronchiectasis, and Multiple myeloma (MM)?

Secondary Causes of Systemic Amyloidosis: Identifying the Exception

Ulcerative colitis is not typically associated with secondary systemic amyloidosis among the listed conditions.

Understanding Secondary Systemic Amyloidosis

Secondary systemic amyloidosis, also known as AA amyloidosis, results from chronic inflammatory or infectious diseases that lead to deposition of amyloid A protein in various organs. This condition differs from other forms of amyloidosis such as AL amyloidosis (associated with plasma cell disorders) or ATTR amyloidosis (associated with transthyretin protein misfolding).

Common Causes of Secondary (AA) Amyloidosis

According to the ACC/AHA guidelines, secondary amyloidosis typically results from chronic inflammatory or infectious conditions 1. The conditions that are well-established causes include:

• Chronic infections:

  • Tuberculosis
  • Leprosy
  • Bronchiectasis (with chronic infection)

• Chronic inflammatory conditions:

  • Rheumatoid arthritis
  • Crohn's disease
  • Psoriasis

• Malignancies:

  • Multiple myeloma (primarily causes AL amyloidosis but can be associated with secondary amyloidosis in some cases) 1

Why Ulcerative Colitis Is the Exception

While inflammatory bowel diseases are mentioned in the guidelines as potential causes of secondary amyloidosis, there is a significant difference between Crohn's disease and ulcerative colitis in this regard:

• Crohn's disease is a well-established cause of secondary amyloidosis
• Ulcerative colitis is rarely associated with secondary amyloidosis 1

This distinction is important because both are inflammatory bowel diseases, but they differ in their propensity to cause secondary amyloidosis.

Evidence for Other Conditions

1. Psoriasis: Multiple case reports confirm the association between psoriasis and secondary amyloidosis, though it is relatively uncommon 2, 3. The chronic inflammatory nature of psoriasis can lead to AA amyloid deposition.

2. Tuberculosis and Leprosy: These chronic infections are classic causes of secondary amyloidosis due to persistent inflammation 1.

3. Bronchiectasis: The chronic infection and inflammation associated with bronchiectasis can lead to secondary amyloidosis 1.

4. Multiple Myeloma: While multiple myeloma is primarily associated with AL amyloidosis (primary), approximately 10-15% of patients with multiple myeloma also have AL amyloidosis 1. It's important to note that this is typically AL amyloidosis rather than AA amyloidosis, but it is still a form of systemic amyloidosis.

Clinical Implications

Understanding the causes of secondary amyloidosis is crucial for:

1. Early detection in high-risk patients
2. Proper management of the underlying condition to prevent amyloid deposition
3. Monitoring for organ involvement, particularly the kidneys and heart

Diagnostic Approach

When secondary amyloidosis is suspected:

• Tissue biopsy with Congo red staining is essential for diagnosis
• Immunohistochemical testing can confirm AA protein type
• Evaluation of organ function, particularly renal and cardiac

Treatment Considerations

The primary treatment approach for secondary amyloidosis focuses on controlling the underlying inflammatory condition, which may halt or slow the progression of amyloid deposition.