Persistence of renal function in a patient diagnosed with concurrent amyloid amyloidosis and immunoglobulin light chain amyloidosis.

Abstract

This case describes a 68-year-old woman exhibiting initial proteinuria at age 55. Subsequently, at age 57, a mixed-type of amyloidosis consisting of amyloid amyloidosis (A A) and immunoglobulin (Ig) light chain amyloidosis (AL) was diagnosed by a renal biopsy examination. Monoclonal paraproteinemia was concurrently identified and diagnosed as monoclonal gammopathy of undeterminate significance (MGUS). Combined melphalan and prednisolone (MP) therapy was initiated. At age 65, anti-hypertensive drugs were administered upon finding an increased urine protein concentration and elevated blood pressure. Because there was no change in the state of MGUS detected by a bone marrow biopsy examination, MP therapy was discontinued. However, the urinary protein concentration increased, and a renal biopsy was performed again at age 66. This revealed a mixed-type amyloidosis of AA and AL, as diagnosed earlier, but AL amyloid deposition in the glomeruli had increased during the intervening period. Life-preserving treatment was continued thereafter, but nephrotic syndrome and renal dysfunction progressed rapidly. End-stage renal failure deposition is rarely seen in the same individual. Although amyloidosis is generally thought to cause a rapid decline in renal function, the patient's renal function was maintained for 13 years. This could be attributed to the following factors : l)the underlying etiology of the AA amyloidosis, which was not clear, 2)a lack of any current evidence of chronic inflammation, and 3) MGUS as the cause of AL amyloidosis. This, together with MP therapy, may have slowed down the pathological decline normally associated with AL amyloidosis.