What is Christmas Disease?
The term “hemophilia B” is understood as a hereditary hemorrhagic diathesis, characterized by a deficiency in the activity of the plasma component of thromboplastin (factor IX).
For the first time, hemophilia B disease was described in 1952. The disease, just like hemophilia A, is inherited recessively, linked to the X chromosome, but a feature of this disease is the location of the structural gene of factor IX at the other end of this chromosome.
Christmas Disease Symptoms
In terms of symptoms, severity and complications of hemophilia B, hemophilia A is identical, these diseases can only be distinguished from laboratory data, which is important for proper therapy. Inhibitory forms of hemophilia B are less common than hemophilia A.
Christmas Disease Diagnosis
Hemophilia B, as well as hemophilia A, is characterized by a violation of general coagulation parameters – prolongation of the total blood clotting time and activated partial thromboplastin time, reduction of coagulation activity in the autocoagulagram during normal prothrombin and thrombin time.
The diagnosis of hemophilia is confirmed by mixing the plasma samples studied with the plasma of patients suffering from already established forms of hemophilia A, B and C. It is obligatory to quantify factor IX, and its severity is judged by the severity of the disease.
Christmas Disease Treatment
Prior to the creation of highly active factor IX concentrates, hemophilia B was treated mainly with frozen or dry donor plasma. In hemophilia, direct blood transfusions are not shown. It is more expedient to use plasma, since factor IX is stable, it is well preserved in it and can be introduced in a sufficiently large amount.
Factor IX is well preserved in frozen plasma (90% of the activity is detected after 6 weeks) and other hemopreparations. It is longer than factor VIII, circulates in the blood of the recipient: the half-life is 18-30 hours. In this regard, plasma transfusions in hemophilia B can be done once a day.
Plasma transfusion makes it possible to increase the level of factor IX by 10-15%, which is sufficient for the relief of acute hemorrhages in the joints and small spontaneous post-traumatic and postoperative bleeding, in particular after the removal of teeth.
Subsequent daily plasma transfusions maintain the concentration of factor IX in the patient’s plasma at the level of 7-14%. This is not enough to relieve and prevent large bleeding, as well as to perform various abdominal, orthopedic or ENT operations.
Stopping and preventing large bleedings are feasible only with the help of factor IX concentrates, which allow to maintain its level in the patient’s plasma at hemostatic values. The required doses of factor IX concentrates are calculated in the same way as for hemophilia A.
To eliminate thrombogenicity, heparin is included in most concentrates; nevertheless, these drugs often shorten the partial thromboplastin time of normal plasma noticeably.
The effectiveness of transfusion therapy is controlled by autocoagulation test, as well as by quantitative determination of factor IX or by ethanol test.
As a preventive measure of bleeding, patients with especially frequently recurring hemorrhages are administered every 10-15 days one of factor IX concentrates at 15 U / kg.
In hemophilia B, such prophylaxis proved to be more effective than in hemophilia A, this is due to slower utilization of factor IX in the organism, as a result of which its plasma concentration in the recipient is maintained above 2% longer. Such prophylaxis is combined with possibly earlier administration of factor IX drugs for hemorrhages.