“Paroxysmal nocturnal hemoglobinuria (Epn) is a very rare disease of the bone marrow, the organ in which all blood cells are produced, and is caused by a random, non-hereditary mutation that causes stem cells to produce red blood cells , white blood cells and ‘defective’ platelets. It affects about 2-5 people per million inhabitants and its most serious complication is thrombosis. However, this disease is not well known by doctors, so the diagnosis is often late. “So Simona Sica, director of Uoc Hematology and stem cell transplantation – Fondazione Policlinico Agostino Gemelli Irccs Catholic University of Rome, speaking at the online press conference” Rare diseases : new opportunities and life prospects for people with paroxysmal nocturnal hemoglobinuria “, promoted by Alexion Pharma Italy, part of AstraZeneca.” And the late diagnosis – continues Sica – still appears today among the main obstacles in identifying the pathology characterized by haemolytic anemia, bone marrow insufficiency and frequent thrombotic events affecting specific areas (thrombosis of the suprahepatic veins and cerebral sinuses). Sometimes Epn can develop as a result of a bone marrow disease called bone marrow aplasia or aplastic anemia – he explains – in which both red blood cells (anemia) and white blood cells (leukopenia) and platelets (thrombocytopenia) are decreased in number. ). In other patients, aplasia can appear later in the clinical history of the disease. “The ‘defective’ red blood cells – continues the hematologist – become sensitive to complement, a mechanism of the immune system, and activate a series of proteins. Defective reds are weak and unable to defend themselves against complement, which then destroys them, causing hemoglobin to leak into them. As a result, a common symptom of Epn is dark-colored urine. This mechanism, called hemolysis, it is active even when the signs are not evident, that is, between a hemoglobinuric crisis and the next. “In addition to the color of the urine, in most cases the classic disease” manifests itself with the symptoms of anemia (lack of red blood cells) : pallor, tiredness, breathlessness and palpitation – continues Sica -. You may feel abdominal pain and difficulty in swallowing solid and even liquid foods. The man may have difficulties in sexual intercourse (dysfunction of the ttile). Other possible symptoms are those secondary to thrombosis, which are different depending on which part of the body is affected. The disease is very variable and due to this variability its symptoms are more or less evident, and can change over time. But even if the clinical manifestations are fleeting or paroxysmal, the pathological mechanism continues to work in the background ”. The most serious complication, adds Sica, “is thrombosis, that is the formation of clots inside the blood vessels, especially the veins. In addition, very severe hemoglobinuric crises increase the risk of kidney damage. If the number of white blood cells is very low (below 1000) the person may be more prone to infections; if the number of platelets is very low (below 50,000) there may be a tendency to bleed. These manifestations generally appear in patients in whom EPN is associated with aplastic anemia ”. According to the expert, the disease “is not well known by doctors”, so “the diagnosis is often late”. The presence of hemoglobin “can be detected by urinalysis – says Sica -. A simple blood draw can also help identify abnormal red and white blood cells with a technique known as flow cytometry. However, this test is only done in centers that specialize in hematology. At the onset of the disease, a bone marrow examination is often conducted to check for bone marrow aplasia or hypoplasia ”. The disease has a significant impact on the quality of life of those affected. “Patients who develop significant anemia, for example, depend on transfusions – recalls Sica – and therefore the disease has a significant impact on daily life. These are weakened patients whose stress also increases the risk of thrombosis. In patients with a previous blood disorder, bleeding or infection may occur. It is therefore clear that the disease represents a heavy burden for both patients and carers “. It must be said, however, that “in 10-15% of cases there may be a spontaneous improvement whereby all the cells of the paroxysmal nocturnal hemoglobinuria have disappeared from the blood and the blood count has returned to normal. Spontaneous healing can also occur in patients with severe disease, but after many years, ”he concludes.