BENNKHOLDA TEST (H. Bennhold) — test for intravital recognition of an amyloidosis. It is based on ability of amyloid (see the Amyloidosis) to connect dye the Congo red entered into blood.
Normal the dye entered into a vein gradually is removed with urine; concentration of paint in blood in an hour after introduction decreases on average by 20%, at the same time in urine paint appears in insignificant quantity. Consider that disappearance from blood (in an hour after introduction) 35 — 60% of paint testifies existence at a sick or nephrotic syndrome, or an amyloidosis, and only disappearance indicates more than 60 — 65% of paint an amyloidosis.
Technology of definition. To the patient on an empty stomach intravenously enter 10 ml of 1% of solution a Congo red (previously take urine for control). 2 — 4 min. later from a vein of other hand take the first portion of blood (10 ml in a centrifugal test tube) and put on ice. Exactly in an hour take for the second time 10 ml of blood. After a blood coagulation of test centrifuge, then colorimetric determine the content of paint. The amount of dye in the first portion is accepted to 100%. Calculation is conducted on a formula:
where A1 and A2 — indications of the colorimeter for the first and second portions of a blood plasma.
At the same time with the second blood sample it is necessary to take urine from the patient. Urine is acidified salt to - that; in the presence the Congo red is observed a posineniye. The amount of the emitted dye is defined colorimetric.
In a crust. time B. of the item practically lost diagnostic value since its negative take does not exclude an amyloidosis, and clearly positive indicators meet rather seldom.
Kogan Ts. Ya. About clinical studying of an amyloidosis by means of test about a Congo red, Klin, medical, t. 16, No. 11, page 1585, 1938, bibliogr.; The guide to clinical laboratory trials, under the editorship of E. A. Kost and L. G. Smirnova, page 265, M., 1964; Bennhold N - über die Ausscheidung intravenös einverleibten Kongorotes bei den verschiedensten Erkrankungen insbesondere bei Amyloidosis, Dtsch. Arch. klin. Med., Bd 142, S. 32, 1923.
V. Ya. Maximov.