New Onset Anemia, Worsened Plasma Creatinine Concentration, and Hyperviscosity in a Patient With a Monoclonal IgM Paraprotein

Abstract

A 76-year-old female followed closely for five years with IgM monoclonal gammopathy of uncertain significance developed anemia, worsened plasma creatinine concentration, and markedly elevated serum viscosity. This case illustrates the scope of pathology that can be caused by elevated blood viscosity. Our patient's anemia was a homeostatic response to normalize systemic vascular resistance and resulted from activation of the systemic vascular resistance response. The elevated plasma creatinine resulted from decreased renal perfusion because of elevated blood viscosity. Recent insights in hemorheology (the study of blood flow) are discussed, namely the recent identification of preferential blood flow patterns and erythrocyte autoregulation of deformability. These insights confirm that blood viscosity is part of the "milieu intérieur."

Keywords: anemia; blood; blood flow; creatinine; erythrocyte deformability; igm; paraprotein; systemic vascular resistance response; viscosity.

Figure 1. Relationship between serum viscosity and plasma creatinine concentration

Serum viscosity is directly related to the plasma creatinine concentration.  The normal range for plasma creatinine is 0.52-1.04 mg/dL and serum viscosity is 1.5-1.9 centistokes.

Figure 2. Relationship of hematocrit and serum viscosity

The hematocrit is inversely related to serum viscosity. The normal range for serum viscosity is 1.5-1.9 centistokes and female hematocrit is 37.0-47.0%.

Figure 3. Preferential blood flow in the frog heart

Preferential blood flow in the frog heart. Normal blood viscosity, cardiac anatomy, and function create a preferential flow pattern that allows the relative separation of oxygenated from deoxygenated blood.  Abnormally low blood viscosity will cause the streamlines to overshoot their targets so that the mixing of oxygenated and deoxygenated blood increases.  High blood viscosity will cause incomplete filling of the ventricle. As a result, the filling of the ventricular apex, that part of the heart which is physically the most distant from the layer of deoxygenated blood, is decreased. The physical separation of oxygenated and deoxygenated blood is diminished, increasing the mixing of the two. Used with permission from iWorx Systems Inc.

Figure 4. Shear rate and wall shear stress in various arteries and arterial beds

Shear rate and wall shear stress in various arteries and arterial beds. Reproduced from reference [8]. Reuse permitted under CC BY-SA 4.0.

Figure 5. Artist rendering of plasma, erythrocyte cell membrane, submembranous space, cytoskeleton, and bulk cell compartment

Artist rendering of plasma, erythrocyte cell membrane, submembranous space, cytoskeleton, and bulk cell compartment.  The submembranous space is estimated to be 5 nm thick, which allows unimpeded diffusion of inorganic ions, which range from tens to hundreds of pm in diameter, and adenosine triphosphate (ATP), which measures 1.4 nm in diameter, throughout the space. The average thickness of the cytoskeleton in the central portion of the erythrocyte is 110 nm (range 88-128 nm) and 54 nm (range 36-72 nm) at the periphery. This is thick enough to sequester hemoglobin molecules, which measure 5 nm in diameter, in the bulk cell compartment. Structures are not depicted to scale. Modified from an original work by David S. Goodsell entitled "Biosites: Red Blood Cell" (2005). Reuse permitted under CC BY-SA 4.0.