Thrombotic thrombocytopenic purpura, or PTT, is a rare but fatal hematologic disease characterized by the formation of small thrombi in blood vessels and is most common in people between 20 and 40 years of age.
In PTT there is a marked decrease in the number of platelets, in addition to fever and, most of the time, neurological impairment due to the change in blood flow to the brain due to clots.
The PTT diagnosis is made by the hematologist or general practitioner according to the symptoms and result of the hemogram and blood smear and treatment should be started soon after, as the disease is fatal in about 95% when untreated.
Causes of PTT
Thrombotic thrombocytopenic purpura is caused mainly by the deficiency or genetic alteration of an enzyme, ADAMTS 13, which is responsible for lowering the von Willebrand factor molecules, and favoring their function. The von Willebrand factor is present in platelets and is responsible for promoting the adhesion of platelets to the endothelium, reducing and stopping bleeding.
Thus, in the absence of the ADAMTS 13 enzyme, the von Willebrand factor molecules remain large and the stagnation process of the blood is impaired and there are increased chances of clot formation.
Thus, PTT may have inherited causes, which corresponds to the deficiency of ADAMTS 13, or acquired, which are those that lead to a decrease in the number of platelets, such as use of immunosuppressive or chemotherapeutic drugs, infections, nutritional deficiencies or auto-diseases -immons, for example.
Signs and symptoms
PTT usually has nonspecific symptoms, however, it is common for patients with suspected PTT to have at least 3 of the following characteristics:
- Acute thrombocythemia;
- Hemolytic anemia, since thrombi formed favor the lysis of red blood cells;
- Fever;
- Renal impairment;
- Neurological impairment, which can be perceived through headache, mental confusion and seizures.
It is also common for patients with suspected PTT to have symptoms of thrombocytopenia, such as the appearance of purple or red spots on the skin, bleeding gums or nose, and the difficult control of bleeding small wounds. Know other symptoms of thrombocytopenia.
Renal and neurological dysfunctions are the major complications of TTP and arise when small thrombus blocks the passage of blood to both the kidneys and the brain, which can lead to renal failure and coma, for example. To avoid complications, it is important that as soon as the first signs appear, a general practitioner or hematologist should be consulted for a diagnosis and treatment to be initiated.
How is the diagnosis made?
The diagnosis of thrombotic thrombocytopenic purpura is based on the symptoms presented by the person, in addition to the result of the hemogram, in which a decrease in the amount of platelets, called thrombocytopenia, is observed, and platelet aggregation can be observed in the blood smear. platelets become attached to each other, as well as schizocytes, which are fragments of red blood cells, as the red blood cells pass through blood vessels that are obstructed by small vessels.
Other tests may also be required to aid in the diagnosis of PTT, such as bleeding time, which is increased, and absence or reduction of the ADAMTS 13 enzyme, which is one of the causes of small thrombus formation.
Treatment for PTT
Treatment for thrombotic thrombocytopenic purpura should be started as soon as possible, as it is fatal in most cases, since formed thrombi can obstruct arteries that reach the brain and decrease blood flow to the region.
The treatment usually indicated by the hematologist is plasmapheresis, which is a blood filtration process in which the excess of antibodies that may be causing this disease and the excess of von Willebrand factor, in addition to supportive care, such as hemodialysis, for example, if there is renal impairment. Understand how plasmapheresis is done.
In addition, the use of corticosteroid and immunosuppressive drugs may be recommended by the physician, for example, to combat the cause of TTP.
