ABSTRACT
The term cryoglobulinemia refers to the presence in the serum of proteins that precipitate
at temperatures below 37°C and redissolve on rewarming. The cryoglobulins can be divided
into three categories: monoclonal, mixed, and polyclonal. Hyperviscosity syndrome
is much more common in monoclonal than in mixed or polyclonal cryoglobulinemia. The
clinical manifestations of cryoglobulinemia depend on the underlying disease and may
involve various organs or systems. Mixed cryoglobulinemia (MC) is dominated by a vasculitic
process, and the clinical manifestations can range from mild to life threatening in
their severity. Another common feature of this disorder is the presence of a benign
smoldering lymphoproliferative process that can evolve (in a limited number of cases)
into non-Hodgkin's lymphoma. The elective treatment for hyperviscosity syndrome, whether
associated with monoclonal, mixed, or polyclonal cryoglobulinemia, is plasma exchange.
In monoclonal cryoglobulinemia, this procedure seems to act by removing large amounts
of abnormal proteins, but its mechanism in MC is far from clear. Here it is possible
that qualitative and quantitative variations in the circulating cryoglobulins, as
well as hemodynamic changes, are at play. This article will focus on the hyperviscosity
syndrome in cryoglobulinemia, beginning with a discussion of its clinical features
and then examining the role of hemorheological parameters in the condition.
KEYWORDS
Cryoglobulinemia - monoclonal - mixed - hyperviscosity syndrome - management - plasma
exchange - hemorheology
