Renal disease is a common problem in multiple myeloma. The pathology is very heterogeneous and may involve a variety of different mechanisms [1-7]. The frequency with which this occurs varies with the definition used for renal insufficiency. In two large series, 43 percent of 998 patients had a plasma creatinine concentration above 1.5 mg/dL (133 µmol/L)  and 22 percent of 423 patients had a plasma creatinine concentration ≥2.0 mg/dL (177 µmol/L) .
There is also a general correlation between the presence and severity of renal disease and patient survival. In the first report noted above, one-year patient survival was 80 percent in those with a plasma creatinine concentration below 1.5 mg/dL (130 µmol/L) versus 50 percent in those with a plasma creatinine concentration above 2.3 mg/dL (200 µmol/L) at disease presentation . The response of the renal disease to therapy also appears to have prognostic value. In the second report, renal functional recovery was seen in 26 percent of those with renal insufficiency at presentation. These patients had a median survival of 28 months compared to four months in those with irreversible renal failure .
A discussion of the types and causes of renal disease is the topic of this review. The pathogenesis and diagnosis of specific associated renal diseases, and the treatment of renal disease in multiple myeloma are discussed separately. (See "Pathogenesis of immunoglobulin light chain (AL) amyloidosis and light and heavy chain deposition diseases" and "Pathogenesis and diagnosis of myeloma cast nephropathy (myeloma kidney)" and "Treatment of kidney disease in multiple myeloma".)
TYPES OF RENAL DISEASE
Renal involvement in multiple myeloma is usually the result of monoclonal immunoglobulin light chains. However, in rare occasions, monoclonal heavy chains or the entire immunoglobulins may be involved. Non-monoclonal protein-related renal injury may also occur. The types of kidney disease can be classified by the primary site of injury:
- Primary (AL or rarely AH) amyloidosis
- Monoclonal immunoglobulin deposition (light chain deposition disease, heavy chain deposition disease, and light and heavy chain deposition disease)
- Miscellaneous (monoclonal cryoglobulinemia, proliferative glomerulonephritis due to monoclonal IgG deposition)
- Collapsing FSGS due to drugs (Pamidronate)