Idiopathic thrombocytopenic purpura

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Classification according to ICD-10
D69.3 Idiopathic thrombocytopenic purpura
Werlhof disease
ICD-10 online (WHO version 2019)

The idiopathic thrombocytopenic purpura ( ITP , now mostly immune thrombocytopenia or immune thrombocytopenia , also called purpura hemorrhagic , thrombocytopenic purpura , autoimmune thrombocytopenia , immunthrombozytopenische purpura ) is an autoimmune disease , the platelet concerns (platelets). Thrombocytopenia (thrombopenia for short) describes a lack of thrombocytes in the blood .

A distinction is made between two forms:

Cause and frequency

Immune thrombocytopenia is the result of an autoimmune process in which mostly free and platelet-bound antibodies (e.g. against the adhesion molecules Gp IIb / IIIa) are detectable and shorten the life of the platelets . When the disease occurs together with autoimmune hemolytic anemia , it is also called Evans syndrome .

It has been observed that acute immune thrombocytopenia is usually preceded by infections of the respiratory system or the gastrointestinal tract; occasionally it also occurs after infections with EBV , CMV or HIV . It is possible that cross-reactive antigens of viral pathogens induce the formation of antibodies (especially immunoglobulin G ) through molecular mimicry . The acute form mostly occurs in children and affects men and women equally often.

Infections of the stomach with Helicobacter pylori have frequently been observed in those affected by chronic immune thrombocytopenia , but this cannot explain all cases of the disease. The cause of the majority of the diseases has not yet been clarified. The chronic form (duration of illness longer than six months is referred to as persistent ITP, duration of illness longer than 12 months is referred to as chronic ITP) preferably affects adults and 75 percent of them women. About 100 cases occur in a million people each year.

Since virus infections or the resulting autoimmune reactions are now assumed to be the triggering cause, immune thrombocytopenia is increasingly gaining ground over the old term idiopathic thrombocytopenic purpura (also known as essential thrombopenia ).

Immune thrombocytopenia is also described as a rare but potentially severe side effect of treatment with alemtuzumab in patients with active relapsing-remitting multiple sclerosis , which can occur 14 to 36 months after the first alemtuzumab infusion.

Clinical picture

The complaints to the ITP can be very different. As a result of the increased breakdown of blood platelets, there is a reduction in platelets and thus an increased tendency to bleed. Punctiform hemorrhages ( petechiae ) in the skin , especially of the legs, and mucous membranes , especially in the throat area, gave the disease its name.

Other symptoms may include nosebleeds or a prolonged menstrual period . The disease becomes threatening when there is bleeding in the brain or the gastrointestinal tract.

Clinical symptoms often only occur when platelet counts are below 30,000 / µl. At values ​​below 10,000 / µl, life-threatening bleeding can occur, but is extremely rare here too. In healthy people there are 150,000 to 350,000 platelets in the microlitre of blood.

therapy

If the Helicobacter pylori (HP) result is positive, HP eradication should be performed. This leads to an increase in platelets in 1/3 of the patients. Often no therapy is necessary because spontaneous healing occurs. Treatment of ITP (for platelets below 30,000 / microliter and / or bleeding) usually begins with the administration of glucocorticoids . If this is not sufficient, immunoglobulin therapy can be used as a further option . The current guidelines recommend a therapy with prednisone, a glucocorticoid, as the first therapy option. A new treatment option is the intravenous administration of anti-D immunoglobulin. Both the response rate and the duration of the increase in the platelet count are better than in therapy with polyvalent immunoglobulins. As an emergency measure in the event of severe bleeding complications that cannot be controlled by drug therapy, there is the option of removing the spleen ( splenectomy ), because this is where the malfunction in the immune system, which causes the fight against platelets, often originates. In any case, it is advisable to carry out a scintigram with radionuclide-marked (ideally your own) platelets before the splenectomy , because the malfunction can also lie in a lymph node , which can thus be localized.

In the case of severe bleeding complications, the administration of foreign platelets ( transfusion of platelet concentrates from blood donors) is also possible. However, these can additionally stimulate the formation of autoantibodies and thereby worsen the course of the disease. In severe cases, it may be necessary to administer cytotoxic drugs to suppress the autoantibody-producing cells.

In some cases, the administration of monoclonal antibodies such as rituximab , also in combination with a subsequent administration of immunoglobulins, has proven to be sustainably successful and also gentler compared to the alternative cytostatic treatment.

Different therapies are effective for different patients. In order to determine the ideal treatment method, it is imperative to graphically depict the development of platelets over the course of therapy, in order to recognize and discontinue an ineffective drug in good time and to work out a new treatment plan because the side effects of the drugs used are so strong that they in themselves have a negative impact on the healing process.

Overall, the cure rate is relatively good at 70 to 80 percent, although a direct connection with the therapy is difficult to demonstrate because of the self-healing rate.

Another treatment option is the administration of non-structurally analogous thrombopoietin preparations (e.g. eltrombopag , romiplostim ), so-called thrombopoietin analogues.

Differential diagnoses

Other diseases that can lead to the same or similar symptoms and laboratory values ​​are in particular:

Web links

Individual evidence

  1. ↑ Drug Commission of the German Medical Association: Therapy-refractory autoimmune thrombocytopenia after alemtuzumab for the treatment of multiple sclerosis. Deutsches Ärzteblatt, vol. 114, issue 46, November 17, 2017 as well as online in the AKDÄ's UAW database
  2. ↑ Andromachi Scaradavou, Bonnie Woo, BMR Woloski, Susanna Cunningham-Rundles, Lawrence J. Ettinger, Louis M. Aledort, and James B. Bussel: Intravenous anti-D Treatment of Immune Thrombocytopenic Purpura: Experience in 272 Patients . In: Blood . 89, No. 8, April 15, 1997, pp. 2689-2700. PMID 9108386 .
  3. ↑ Kuter DJ et al. Efficacy of romiplostim in patients with chronic immune thrombocytopenic purpura: A double-blind randomized controlled trial. Lancet 2008 Feb 2; 371: 395.