The hyperviscosity syndrome(HVS) in several hematologic diseases including the paraproteinemia has been well known consequence of hemorheological abnormality and the abnormal blood viscosity might be implicated in the pathogenetic role in the occlusive vascular diseases.
The authors have investigated the whole blood and plasma viscosity using rotational cone-plate microviscometer in 30 healthy subjects (control group) and 36 cases with
various hematologic diseases (AML 8, ALL 4, acute mixed lineage leukemia 1, CML 9, plasma cell dyscrasia ; PCD 8, erythrocytosis 5, Sezary syndrome 1).
The results were as follows ;
1. In the control group whole blood viscosity at shear rate 120 sec-1 was 5.69±0.95(range ; 3.79-7.59) mPa.s and plasma viscosity was 1.46±0.15(1.16-1.78) mPa.s.
2. Among the patients group, whole blood viscosity in erythrocytosis(8.81±1.08 mPa.s) and plasma viscosity in PCD(2.83±1.74 mPa.s) were significantly increased comparing to
those of control group.
3. There was a close linear correlation between whole blood and plasma viscosity in PCD, and serum globulin was the most significant factor.
4. The determinants of whole blood viscosity was cytocrit in acute and chronic myelogenous leukemia and was hematocrit in acute lymphocytic leukemia and non-leukemia group.
5. In acute leukemia, while correlation was not found between increased blood viscosity and hyperviscosity syndrome(HVS), a case with elevated whole blood viscosity
developed cerebral HVS. In 2 cases with PCD accompanying HVS, whole blood(8.92, 10.90 mPa.s) and plasma(4.58, 6.20 mPa.s) viscosity were increased compared to normal.
Based upon the above results, it is concluded that the determinants of blood viscosity are differed in each disease group and also the mechanism(s) of HVS seems to be. The blood viscosity measurement could be useful guideline to decide the therapeutic strategy in hematologic diseases prone to develop hyperviscosity syndrome.

Keywords: Blood viscosity, Hyperviscosity syndrome, Leukemia, Multiple myeloma, Polycythemia,