Plasma cell dyscrasias (also termed plasma cell disorders and plasma cell proliferative diseases) are a spectrum of progressively more severe monoclonal gammopathies in which a clone or multiple clones of pre-malignant or malignant plasma cells (sometimes in association with lymphoplasmacytoid cells or B lymphocytes) over-produce and secrete into the blood stream a myeloma protein, i.e. an abnormal monoclonal antibody or portion thereof. The exception to this rule is the disorder termed non-secretory multiple myeloma; this disorder is a form of plasma cell dyscrasia in which no myeloma protein is detected in serum or urine (at least as determined by conventional laboratory methods) of individuals who have clear evidence of an increase in clonal bone marrow plasma cells and/or evidence of clonal plasma cell-mediated tissue injury (e.g. plasmacytoma tumors). Here, a clone of plasma cells refers to group of plasma cells that are abnormal in that they have an identical genetic identity and therefore are descendants of a single genetically distinct ancestor cell. At one end of this spectrum of hematological disorders, detection of one of these myeloma proteins in an individuals blood or urine is due to a common and clinically silent disorder termed MGUS, i.e. monoclonal gammopathy of undetermined significance. At the other end of this spectrum, detection of the myeloid protein is due to a hematological malignancy, i.e.
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.