Reflecting the widespread systemic nature of the disease, patient median survival is only 8 months dating from the time of diagnosis. Treatment commonly improves this poor survival. In a Mayo Clinic study, for example, AL amyloidosis assigned stage 1, 2, 3, or 4 based on the presence of 0, 1, 2, or 3 prognostic signs (high blood levels of [cardiac troponin T]), blood levels of a marker for congestive heart failure (viz., NT-ProBNP), or free light chain ratios) had median survivals of 94.1, 40.3, 14, and 5.8 months respectively. Additional factors indicating a worse prognosis include the involvement of multiple organs, ≥ 10% bone marrow plasma cells, presence of a translocation between chromosomes 11 and 14 [i.e. t(11;14)], and chromosomal trisomy. AH Amyloidosis
AH and AHL amyloidosis are extremely rare forms of systemic amyloidosis in which the amyloid deposit is a free heavy chain (AH amyloidosis) or a free heavy chain plus free light chain (AHL amyloidosis). Case reports have detected amyloid deposits containing a free γ, α, or μ heavy chain (or portions of one of these chains) accompanied in many cases by a free κ or λ light chain in primarily in the kidney but also the spleen and other tissues. AH plus AHL amyloidosis cases are ~17-fold less common than AL amyloidosis cases. The disease often presents late in its course with signs and/or symptoms of kidney failure such as those associated with the nephrotic syndrome and is therefore treated as a malignant condition.
Myeloma protein toxicities include: 

Monoclonal free light chains, free heavy chains, or a mixture of these chains can deposit in the kidney and other organs to cause systemic monoclonal immunoglobulin deposition disease; free κ or λ light chains can deposit selectively in the kidneys proximal tubule to cause light chain proximal tubulopathy or in the kidneys distal tubule to cause light chain myeloma cast nephropathy; and various myeloma proteins can deposit selectively in the kidneys glomeruli to cause various forms of organized deposit and non-organized deposit glomerulonephritis diseases. Free κ or λ light chains can aggregate with each other to cause extracellular amyloid deposits and a disease termed amyloidosis in which the deposits injure and ultimately lead to the failure of such organs as the kidney, heart, liver, stomach, and intestines; these deposits can also cause peripheral and autonomic neuropathies. IgM myeloma proteins or in rare cases other myeloma proteins such as IgA, free κ light chains, or free λ light chains may increase blood viscosity, deposit in peripheral blood vessels, and thereby cause vascular occlusion and gangrene of the extremities in the syndrome termed cryoglobulinemia. Monoclonal IgM myeloma proteins operating through their effects on increasing blood hyperviscosity can reduce blood flow to the central nervous system to cause blurred vision, headaches, vertigo, ataxia, and cold-induced hemolytic anemia. IgM, IgG, and to lesser extents κ and λ free light chain myeloma proteins can cause Immune thrombocytopenic purpura with extensive bleeding tendencies .