Manitoba Nephrology Nurse Practice Test

What is a major consequence of the excess immunoglobulin chains produced in Multiple Myeloma?

1. Increased fluid retention

2. Tubular damage due to nephrotoxicity

3. Enhanced glomerular filtration rate

4. Hypertension due to fluid overload

The correct answer is: Tubular damage due to nephrotoxicity

In Multiple Myeloma, a key feature is the abnormal production of monoclonal immunoglobulin chains, or light chains, by malignant plasma cells. These excess light chains can lead to kidney damage primarily through a process called cast nephropathy. When the concentration of these light chains exceeds certain thresholds, they can precipitate in the renal tubules, forming obstructive casts that cause tubular injury. This can ultimately lead to acute kidney injury (AKI) and chronic kidney disease (CKD). The nephrotoxicity arises because the damaged renal tubules struggle to filter waste effectively, leading to a cascade of renal issues. Additionally, the presence of increased light chains in the blood can contribute to a condition known as myeloma kidney, which is characterized by damage to both the glomeruli (the filtering units of the kidney) and the renal tubules due to the toxic effects of these proteins. This understanding of how the excess immunoglobulin chains can cause tubular damage is crucial in managing renal complications in patients with Multiple Myeloma, making it clear why this consequence is significant in nephrology nursing.