PREVIOUS studies (Lob et at., (1971)) have shown that blood volumes of paraplegics, which are measured by the R-I25-IHSA-method, may result in unreliable values because the elimination rate of homologous human serum albumin is often in creased in these patients. It can be speculated on one hand that the increased elimination rate might be the result of an elevated catabolism of radio-iodinated human serum albumin; on the other hand immunological mechanisms could be the cause, i.e. a developing clinical incompatibility to homologous human serum albumin. With the following investigations it should be elucidated whether or not immune reactions are responsible for the high elimination of human serum albumin in paraplegic patients.
PATIENTS AND METHODSThe investigations were done in 24 male and six female paraplegic patients of ages between 18 and 60 years; the results were compared with those of ten normal healthy volunteers. The paraplegic lesions of the patients were at least two weeks old, with a maximum of 20 years. Six patients had lumber spine lesions, II thoracic spine and 13 cervical spine lesions. Twenty-four patients were completely paralysed and six patients incompletely paralysed.The elimination rate of human serum albumin (per cent/hour) was measured with I25-iodine labelled homologous human serum albumin (Fa. Buchler + Co, specific activity 10 /LCi./mg.). Before applying radio-active labelled human serum albumin the thyroid gland was blocked with Endojodin (R) (Fa. Bayer) in order to prevent a selective storage of radio-active iodine in this organ. After the intravenous application of IOO /LCi. R-I25-IHSA the radio-activity was measured in 1 m!. of heparinised blood samples at time intervals of I, 5, 10, 20, 30 and 60 minutes.Furthermore, the body weight, the hematocrit, the erythrocyte sedimentation rate (ESR), the osmolarity, the colloid osmotic pressure, the total serum protein and the serum electrophoresis were controlled.In five patients the disappearance rate of homologous R-I25-IHSA was compared with that of autologous 131 -J human serum albumin according to the method of the immune elimination technique . For this purpose the radio-activity in I m!. heparinised blood was determined at daily intervals over a period of three weeks. The autologous albumins were produced by the same fractionation procedure as the normal homologous HSA and labelled with 131:-iodine (Berson et at., 1953;Glaubitt and Rippel, 1967). Autologous and homologous albumin fractions were compared prior to an administration by radiochromatography.13 9