Kidney Donation with Localized Nasopharyngeal Amyloidosis
A person with localized nasopharyngeal amyloidosis who has shown no clinical signs of systemic disease for 6 years can likely donate a kidney, as localized amyloidosis does not pose the same risks as systemic forms of the disease.
Understanding Amyloidosis Types and Kidney Implications
- Amyloidosis is classified into different types based on the precursor protein that forms amyloid fibrils, with AL (light chain) and ATTR (transthyretin) being the most common systemic forms 1
- Localized amyloidosis differs fundamentally from systemic forms, as it remains confined to a specific tissue or organ without evidence of systemic involvement 2, 3
- In systemic AL amyloidosis, the kidney is one of the most common sites of amyloid deposition, affecting approximately 70% of patients, typically presenting with nephrotic syndrome and progressive kidney dysfunction 1
- Localized nasopharyngeal amyloidosis is a rare condition that typically presents with nasal obstruction, epistaxis, or hearing impairment, without systemic manifestations 2, 3
Evaluation for Kidney Donation in This Context
- The absence of clinical signs of systemic disease over a 6-year period strongly suggests true localized amyloidosis rather than an early manifestation of systemic disease 4, 5
- For living kidney donors with any history of amyloidosis, comprehensive evaluation should include:
- Confirmation that the amyloidosis is truly localized through thorough clinical assessment 1
- Screening for proteinuria and assessment of kidney function using cystatin C-based GFR measurements (more accurate than creatinine-based methods in patients with potential amyloidosis) 1
- Evaluation for any signs of cardiac involvement, which would be concerning for systemic disease 1
Risk Assessment and Recommendations
- The primary concern with systemic amyloidosis is the risk of recurrence in transplanted organs, which is not applicable in cases of truly localized disease 1
- Unlike hereditary forms of amyloidosis (such as hereditary ATTR), localized nasopharyngeal amyloidosis is not genetically transmitted and does not pose a risk to donated organs 1, 4
- The 6-year disease-free period without systemic manifestations provides strong evidence that the condition is truly localized and stable 2, 3
- Kidney donation evaluation should follow standard protocols for living donors, with special attention to ruling out subclinical kidney involvement through sensitive testing for proteinuria 1
Potential Concerns and Monitoring
- While rare, there is a theoretical possibility that localized amyloidosis could progress to systemic disease over time, though this is unlikely after 6 years of stability 4, 5
- The donor should be informed about this theoretical risk and the importance of regular follow-up after donation 1
- Post-donation monitoring should include periodic assessment for proteinuria and kidney function, which would be standard for any kidney donor 1
Conclusion
Based on current evidence, a history of localized nasopharyngeal amyloidosis with no signs of systemic involvement for 6 years should not preclude kidney donation. The evaluation should focus on confirming the absence of subclinical kidney involvement and ensuring adequate kidney function for donation 1.