DE2148865B2 - Use of a streptokinase-plasminogen complex for fibrinolysis - Google Patents

Description

The invention relates to a complex composed of streptokinase and plasminogen which is used for intravenous treatment of thromboembolic diseases is suitable.

Under the action of streptokinase, a metabolic product of ß-haemolytic streptococci, the plasminogen of the blood is converted into the prolease plasmin, which is able to dissolve fibrin clots and therefore used clinically to induce fibrinolysis. Streptokinase has as a foreign substance the property of forming antibodies in the macroorganism, and therefore patients cannot given repeatedly as this may cause side reactions. It has already been tried Streptokinase decreased antigenicity due to treatment to be obtained with proteolytic ferments. However, there can also be residual antigenicity in sick people Cause undesirable reactions to people.

The invention relates to the use of a complex of streptokinase and human plasminogen in a molar ratio of 2: 1 to 1: 2, preferably 1: 1.

The molar weight of human plasminogen is about 84,000 and that of streptokinase is about 47,000.

Streptokinase and human plasminogen go together a more or less strong chemical Bond, depending on the conditions under which they are brought together. The connection is dissociable with F-aminocaproic acid, provided the reaction running in the cold. If heat is used for this purpose, stronger ones must be used for a split Agents,? .. B. urea are used. It can be assumed that there is a chemical in the heat Reaction takes place as in the treatment of the Rcak'.ionsprodukts with urea a streptokinase of reduced clektrophoretic mobility is released will.

Both streptokinase and plasminogen are commercially available preparations.

It is true that in Yale J. Biol. Med. (1954) 26, 365-71 Streptokinase used together with plasminogen, but there is the ratio of streptokinase to plasminogen at most 0.003 and thus far outside the claimed range of 2 to 0.5. Surprisingly the claimed complex is also not affected by the plasma inhibitors present in the plasma inhibited and thus proves to be easy to dose. Furthermore, that was not to be expected the complex would be stable for the duration of infusion treatment and retain its beneficial properties. Rather, it would have been expected that the streptokinase-induced conversion of the Plasminogen in plasmin would continuously run off.

pc jet continues to be surprising and so far has not been known that human plasminogen lend the antigenic groups of streptokinase to that of humans The organism is masked and the intravenous injection of streptokinase, which is often life-saving, is risk-free > does.

The streptokinase-plasminogen complex is used to treat thromboembolic diseases and is effective even if the patient is through previous contact with streptococci or

in has antibodies against streptokinase from previous injection with streptokinase.

The streptokinase associated with plasminogen is hardly accessible to the homologous antibody. This knowledge can be proven by

r> in different approaches to constant amounts of streptokinase increasing amounts of human plasminogen gives and these mixtures of different plasminogen contents equal amounts of the homologous Adding antibody. With increasing amounts of the

J "Plasminogen is the precipitability of the Streptokinase decreased by the antibody.

On the other hand, the streptokinase can be eliminated by epsilon-aminocaproic acid displace plasminogen from the compound and then react again

: ■> unreservedly with your homologous antibody. When guinea pigs are immunized with streptokinase, they form antibodies against streptokinase. An injection of streptokinase after three weeks therefore elicits a shock reaction. Will

in contrast, the guinea pigs after three weeks of the Streptokinase-plasminogen complex is injected, this injection is tolerated without reaction.

If, on the other hand, guinea pigs are treated with the streptokinase plasminogen active agent according to the invention

i. tor immurisizes, they do not form antibodies against streptokinase, but those against human plasminogen. The animals immunized in this way tolerate after three weeks exposure to streptokinase without complications, but they respond to one

in boosting with the activator according to the invention with symptoms of allergy or anaphylaxis due to the presence of human plasminogen antibodies.

An additional advantage of the invention

< -. The complex lies in the fact that it remains unaffected by the natural inhibitors of the blood. This allows it to penetrate unhindered to the blood clot and cause it to dissolve. No preliminary tests have to be carried out, the preparation can

.Ii can be dosed evenly.

example

A 2% igc solution of streptokinase in physiological Sodium chloride solution and a 1% solution v> of human plasminogen in 0.1 molar sodium phosphate buffer are used in the following batches mixed in an ice bath, with constant amount of streptokinase and increasing amounts of cmc Plasminogen can be added.

"II (1)

0.1 ml streptokinase

f 0, y ml phys. chloride

(2)

0.1 ml streptokinase
h, + 0.2 ml plasminogen f 0.7 ml phys. chloride

0.1 ml streptokinase

4- π 1 ml PlucminoaiMi 4- 0 (λ ml nlvjs N '* tf chloride

0.1 ml streptokinase

+ 0.4 ml plasminogen + 0.5 ml phys. chloride

0.1 ml streptokinase

+ 0.5 ml plasminogen + 0.4 ml phys. chloride

0.1 ml streptokinase

+ 0.6 nil plasminogen + 0.3 ml phys. chloride

For testing the precipitability with streptokinase antiserum the mixtures are used in immunoelectrophoresis examined at pH 8.6. For this purpose, the mixtures are left with antiserum against streptokinase react. The free streptokinase contained in the mixture forms antibodies with the homologous a precipitate. With increasing concentration of the plasminogen, the precipitability decreases, to finally in batch 5, the streptokinase and human plasminogen contains in a weight ratio of 1: 2.5, no more precipitate occurs.

The reduced reactivity with the homologous antibody can also be demonstrated in animal experiments will.

10 guinea pigs are single subcutaneous Injection of 0.5 ml of a 0.2% streptokinase solution immunized. 21 days later, 5 animals received 0.5 ml of the 0.2% streptokinase solution and 5 other animals 0.5 ml of a complex containing streptokinase and plasminogen in a ratio of 1: 2.5, injected intravenously.

All animals injected with a streptokinase-plasminogen complex showed no reaction. In contrast, all of the guinea pigs immunized with streptokinase and challenged after 21 days were given a shock. Three of them perished.

19 guinea pigs are using a complex that Contains streptokinase and plasminogen in a ratio of 1: 2.5, immunized subcutaneously. After 21 days will

9 animals intravenously with the complex used for immunization and the other 10 animals with 0.5 ml of 0.2% streptokinase alone exposed.

All 9 animals that were boosted with the complex fell into shock. 5 of them perished. the

In contrast, 10 animals exposed to streptokinase alone survived. Only one showed a slight shock effect, proof that the antigenicity the complex according to the invention and its property to form antibodies, largely reduced, if not canceled.

Claims (1)

Claim: Use of human pasminogen linked to streptokinase, the molar ratio from streptokinase to human plasminogen 2: 1 to 1: 2, preferably 1: 1, in the intravenous treatment of thromboembolic Diseases.