Chapter 34: Plasma Cell Dyscrasias
What are the most important risk factors in the development of cast nephropathy?
A. More than 60% bone marrow plasma cells and more than one focal bone lesion on MRI
B. Anemia and hypercalcemia
D. Serum free light chain level more than 50 mg/dL and a high-urinary free light chain excretion
E. The use of non-steroidal anti-inflammatory drugs and intravenous contrast agent
The answer is D. Both of these have been shown in large studies to predict the development of acute renal failure and cast nephropathy. A contains new definitions for symptomatic multiple myeloma but not cast nephropathy. B and C are parts of the CRAB criteria that define symptomatic multiple myeloma but not for cast nephropathy. E contains risk factors that could increase the risk of cast nephropathy but would not precipitate cast nephropathy on their own with the other risk factors.
Which of these is the most helpful in predicting the recovery of renal function after cast nephropathy?
A. The isotype of the immunoglobulin light chain
B. The baseline free light chain ratio
C. The percent reduction of the serum-free light chain
D. The cytogenetic FISH results of the multiple myeloma
The answer is C. The recovery of renal function from cast nephropathy is predicted by the percent reduction of serum-free light chain and the speed at which that is accomplished. None of the other has been shown to have any prognostic value.
What is the minimum level of hematologic response required to increase the chances of a renal response in AL amyloidosis?
A. A complete response: the absence of a monoclonal protein by serum and urine immunofixation and a normal free-light chain ratio
B. A very good partial response: dFLC less than 4 mg/dL or more than 90% reduction of the dFLC
C. A partial response: 50% reduction of the dFLC
D. Absent of clonal plasma cells in the bone marrow
E. Normal serum-free light chains
The answer is B. Studies have shown a minimum of VGPR is necessary for improvement of organ dysfunction in AL amyloidosis including the ...