idiopathic pulmonary hemosiderosis
Introduction
Introduction to idiopathic pulmonary hemosiderosis Idiopathic pulmonary hemoglobinosis (IPH) (iron is located in the lungs) is a rare and serious disease in which blood leaks from the capillaries to the lungs for unknown reasons. The disease mainly affects children but is also seen in adults. Some of the blood leaking out of the capillaries can be swallowed by the clear cells in the lungs. The decomposition products of blood stimulate the lung tissue to form scars. The main symptom is hemoptysis, the frequency and extent of which depends on the amount of blood leaking from the capillaries into the lungs. Difficulty in breathing can occur after the formation of scars in the lungs. Excessive blood loss can cause anemia; a large number of bleeding can cause death. The main purpose of treatment is to relieve symptoms. Corticosteroids and cytotoxic drugs such as azathioprine help to control seizures. Those who have excessive blood loss need blood transfusion, and those who have hypoxemia should receive oxygen therapy. basic knowledge The proportion of illness: 0.005% Susceptible people: no specific population Mode of infection: non-infectious Complications: pulmonary hypertension, pulmonary heart disease, cardiomyopathy, iron deficiency anemia, respiratory failure
Cause
Idiopathic pulmonary hemosiderosis
Immunity factor (30%):
Many scholars believe that this disease is related to immunity. The serum IgG, IgA, and IgM are increased, and IgA is more obvious. In some patients, eosinophils are increased, lung mast cells are concentrated, and antinuclear antibodies and cold globulin antibodies are positive. Some cases are effective by adrenal cortical hormone, immunosuppressive agents or plasma exchange, which support the disease and immune dysfunction.
Milk allergy (20%):
Some children with milk allergy have positive skin test in milk. The serum has been found to react with the milk antigen. After the milk is stopped, the clinical symptoms disappear. The author Heiner reported that 4 cases of children with milk allergy were diagnosed with IPH. Such patients are called Heiner syndrome, but milk allergy does not explain the onset of all children.
Related to exposure to organophosphorus pesticides (10%):
In Greece, Cassimos surveyed 30 children who had developed the disease and found that 80% of the children were growing in the countryside, with poor economic conditions and less protein in the diet; 50% of the children had a history of continuous exposure to organophosphorus pesticides. Cassimos believes that pesticides may induce this disease in some children, and the exact basis needs further investigation.
Genetic factors (10%):
The patient was diagnosed with genetic factors due to the close relationship between the parents, or the siblings and twins, but no genetic confirmation.
Alveolar epithelial cell development and dysfunction (15%):
It destroys the stability of alveolar capillaries and causes repeated bleeding, but the etiology of epithelial cell abnormalities is still unclear.
Abnormal pulmonary fibrosis (10%):
The elastic fiber has an abnormal acidic mucopolysaccharide, which weakens and expands the blood vessel wall.
Pathogenesis
General examination
The appearance of the lungs is brown and solid, the weight and volume are increased, the surface and the cut surface are scattered in the bleeding spots and diffuse brown pigmentation, the hilar and mediastinal lymph nodes are swollen, and the hemosiderin is brown and acute. Hemorrhage can be seen, and diffuse interstitial fibrosis is more obvious in the chronic phase.
2. Optical microscopy
Alveolar epithelial cells swell, degeneration, shedding and hyperplasia, phagocytic cells containing red blood cells or hemosiderin, alveolar wall elastic fiber degeneration, capillary proliferation, basement membrane thickening, pulmonary arterial elastic fiber degeneration, including Hemosiderin, intimal fibrosis, hyalinization, lymphocytes around the lymphatic vessels, infiltration of plasma cells and hemosiderin macrophages, lymphatic vessel expansion, diffuse pulmonary fibrosis in the later stages of the disease, emphysema , bronchiectasis, etc.
3. Electron microscopy
Extensive alveolar capillary damage, endothelial cell edema, type II alveolar epithelial cell hyperplasia, focal rupture of the basement membrane, protein deposition in the basement membrane, loss of normal structure of the basement membrane.
Prevention
Idiopathic pulmonary hemosiderin prevention
IPH due to milk, dairy products or gluten should be banned.
Complication
Idiopathic pulmonary hemosiderosis complications Complications pulmonary hypertension pulmonary heart disease cardiomyopathy anemia anemia respiratory failure
1. Pulmonary hypertension can be caused by extensive pulmonary interstitial fibrosis, followed by pulmonary heart disease and heart failure. A small number of patients can develop cardiomyopathy and can die.
2. Combined with large liver, splenomegaly is also more common.
3. Combined with ischemic anemia. Due to repeated spontaneous intrapulmonary hemorrhage, the hemoglobin in the lungs is deposited, and most of the iron is lost from the sputum. Therefore, the anemia of the disease is an iron deficiency anemia caused by chronic blood loss, which can be combined with pulmonary hemorrhage and respiratory failure. .
Symptom
Idiopathic pulmonary hemosiderosis symptoms common symptoms hemosiderin depression repeated bleeding vocal dyspnea low fever chest tightness fatigue stagnation blood pale
Clinical manifestations and lesions vary in degree and performance.
Acute bleeding period is sudden onset, episodes of dyspnea, cough, hemoptysis, anemia, hemoptysis can be more or less, patients feel chest tightness, shortness of breath, rapid breathing, palpitations, fatigue, low fever, pale face, lung examination can be normal It can be heard and wheezing, the breath sound is reduced, or the fine wet voice can be heard. In severe cases, myocarditis, arrhythmia, atrioventricular block and even sudden death can occur.
Chronic recurrent episodes of cough, hemoptysis, recurrent dyspnea, repeated alveolar hemorrhage, and finally lead to extensive interstitial fibrosis of the lungs, patients often have chronic cough, shortness of breath, low fever, anemia, general fatigue, fatigue, late stage of the disease can be complicated by lung Swelling, pulmonary hypertension, pulmonary heart disease and respiratory failure, some patients may have clubbing, and a few patients may have hepatosplenomegaly.
Examine
Examination of idiopathic pulmonary hemosiderosis
1, blood picture: showing iron deficiency small cell hypochromic anemia, reticulocyte increase, due to iron deposition in alveolar macrophages, can not be transported as a synthetic hemoglobin, serum iron and iron saturation is significantly reduced, red blood cell salt brittleness The test is normal, the peripheral blood eosinophils can be increased, the erythrocyte sedimentation rate is increased, and the hemoglobin can be increased in the alveoli, so the serum bilirubin can be increased, the serum IgA is increased, the direct Coombs test, the condensation set test, and the phagic agglutination test can be positive. The serum lactate dehydrogenase can be increased, and the electrocardiogram of the heart can be abnormal. The typical hemosiderin macrophages found in the gastric juice, bronchoalveolar lavage fluid or lung biopsy tissue are important for diagnosis.
2, blood gas analysis: patients with more normal early, alveolar hemorrhage or extensive pulmonary interstitial fibrosis, PaO2 decreased, normal or decreased, severe cases may present with type I respiratory failure, late emphysema, pulmonary heart disease and respiratory failure At the time of PaO2 decline, PaCO2 can be elevated, and blood gas analysis can be expressed as type II respiratory failure.
3, pulmonary function test: acute phase due to alveolar hemorrhage, red blood cell hemoglobin can take a certain amount of CO, so the CO diffusion of lung function Dco increased, Dco must be corrected with hemoglobin value in anemia, chronic pulmonary fibrosis, lung dispersion Decreased function, lung compliance, total lung volume and residual volume, restrictive ventilatory dysfunction, late emphysema, pulmonary heart disease, maximum ventilation, one second forced expiratory (FEV1) decreased, indicating mixed Ventilation dysfunction.
4, X-ray inspection:
(1) Acute attack: chest X-ray can be normal, but also can display a variety of manifestations, more common two lungs increased texture, diffuse patch of both lungs, spot-like shadow, to the middle and lower lung field and lungs Sometimes it can be fused into large patches or cloud-like shadows. A few patients show localized or unilateral lung lesions. The hilar and mediastinal lymph nodes can be enlarged. In most cases, lung lesions are obviously absorbed within 1-2 weeks. It can last for months or repeatedly.
(2) Chronic seizure intermittent period: see extensive interstitial fibrosis changes, and there may be cystic transparent areas in severe lung slices.
5, chest CT examination: chest CT examination can be found earlier in the bilateral middle and lower lungs as diffuse small nodular shadow.
6, lung biopsy and fiberoptic bronchoscopy: alveolar bleeding for a long time, fiberoptic bronchoscopy can be seen in the blood of the bronchus, through fiberoptic bronchoscopy lung biopsy or open lung biopsy and other methods can be done by light and electron microscopic pathological observation, Identify the cause of alveolar bleeding.
Diagnosis
Diagnosis and diagnosis of idiopathic pulmonary hemosiderosis
Diagnostic points
All cases of iron deficiency anemia with hemoptysis should consider the possibility of this disease, especially to pediatricians to strengthen the understanding of the disease, so as to avoid missed diagnosis and misdiagnosis, the main basis for diagnosis:
1 clinical manifestations;
2 various manifestations of iron deficiency anemia;
3 repeated hemoptysis, there are a large number of macrophages that phagocytose hemosiderin particles, lung X-ray examination can be used as a reference;
4 conditional lung biopsy should be performed to obtain pathological evidence.
Differential diagnosis
1. The disease is closely related to pulmonary hemorrhagic nephritis syndrome (pulmonary-renal syndrome, Goodpasture syndrome). The syndrome is characterized by recurrent alveolar hemorrhage and iron deficiency anemia accompanied by glomerulonephritis. It is also a rare disease. Most of the patients are young people. Males account for about 75%. There are also reports of 78-year-old women. The initial symptoms are often hemoptysis and shortness of breath. Rarely, a large number of hemoptysis X-ray examinations have cloud samples of both lungs. Infiltrating the image, after which hemoptysis recurrent, and glomerulonephritis appears in the urine protein, red blood cells and casts, clinical manifestations of acute glomerulonephritis, renal function is progressive, most of the early nitrogen Hememia, often dying of uremia in weeks or years.
2. Pulmonary hemosiderosis is differentiated from other diseases with anemia and hemoptysis: especially bronchiectasis and tuberculosis, the latter two diseases can not only disappear in the bone marrow, but also tend to increase, bronchiectasis The sputum is often purulent, and the disease contains hemosiderin granules, cytology and bacteriological examination of sputum and lung X-ray examination to help identify these diseases.
3. Some cases of this disease have elevated serum bilirubin, increased urinary bilirubin, increased reticulocytes, and hyperplastic anemia in the bone marrow. It is easy to be hemolytic anemia, especially if the hemoptysis is mild, but the free hemoglobin is not increased in this patient. The combination of globin is not reduced, the cytological examination of sputum and the histopathological examination of the lung can be differentiated from hemolytic anemia. In addition, it is reported that infants and young children will be swallowed and will be clinically mistaken for gastrointestinal bleeding. To improve the vigilance of the disease, careful observation of the condition and the necessary laboratory and X-ray examination identification is not very difficult.
