Nonspecific interstitial pneumonia

Introduction to nonspecific interstitial pneumonia Nonspecific interstitia lpneumonia (NSIP) is a type of idiopathic pulmonary interstitial disease (IIP). Unlike common interstitial pneumonia, NISP can be seen in the pathology of mononuclear cell invasion or pulmonary interstitial fibrosis. The inflammatory cells are mainly composed of lymphoid plasma cells and interstitial macrophages. The honeycomb lung is rare, often with type II epithelial cells showing linear proliferation, and only fibroblast proliferation and collagen deposition occur in the late stage. In the past, non-specific interstitial pneumonia was summarized in idiopathic pulmonary interstitial fibrosis due to its clinical, pathological, imaging, and pulmonary function changes, especially for the treatment response and prognosis of glucocorticoids and IPF. Different, so it has been separated from IPF in recent years. As an independent idiopathic pulmonary interstitial disease, its clinical symptoms and pathological features are relatively lack of specificity. The clinical diagnosis is mostly IPF. In fact, it is actually different. disease. basic knowledge The proportion of sickness: 0.42% Susceptible people: more common in middle-aged and elderly Mode of infection: non-infectious Complications: heart failure, respiratory failure

The cause of non-specific interstitial pneumonia

(1) Causes of the disease

The cause is unknown.

(two) pathogenesis

Pathological manifestations of NSIP: Different degrees of inflammation and fibrosis in the thickened alveolar wall, according to the proportion of inflammation and fibrosis, the disease is divided into 3 types: 1 cell type, accounting for about 50%, mainly in the lungs Inflammatory inflammation, little or no fibrosis, is the earliest histological manifestation of NISP. The chronic inflammatory cells in the alveolar septum are mainly lymphocytes and plasma cells infiltrating, and the degree of infiltration is more prominent than IPF; 2 mixed type, about Accounted for 40%, the lung interstitial is characterized by a large number of chronic inflammatory cell infiltration and obvious collagen fiber deposition, the lesions are relatively consistent, no honeycomb lung, some patients can see a small number of fibroblasts; 3 fibrosis type, about 10% The lung interstitium is mainly composed of dense collagen fibers with slight inflammation or lack of inflammation. The NSIP lesions are flaky or diffuse, but the lesions are consistent throughout the time, with few simple fibrosis. District, can not see the phenomenon of coexistence of new and old lesions like IPF, chronic inflammatory cell infiltration around the bronchi, alveolar type II epithelial hyperplasia, focal or flaky alveolar macrophage accumulation, common foam Cells, nearly half of patients have BOOP focal change, the small proportion of the lack of acute lung injury small vessel cellulose thrombus, hyaline membrane and alveolar epithelial metaplasia.

NSIP should be mainly identified with IPF. In particular, pulmonary fibrosis should be differentiated from IPF. The important pathological features of IPF are the presence of fibroblastic foci, the combination of scarring of collagen deposition and different phase lesions of honeycomb formation. Characteristics, nearly half of the cases of NSIP have focal BOOP changes, but the proportion of the entire lesion is small.

Non-specific interstitial pneumonia prevention

1, to ensure that there is enough rest, but also to keep warm, to avoid cold, to prevent various infections. Pay attention to climate change, especially in the winter and spring seasons. The temperature changes drastically, and the clothes are increased or decreased in time to avoid aggravating the condition after the cold.

2. Have a comfortable living environment. Keep the room quiet, keep it clean, keep the air fresh, moist, and circulate. Avoid irritating factors such as smoke, perfume, air fresheners, etc., and avoid inhaling too cold, too dry, too humid air.

3, diet, diet should be light, easy to digest, mainly liquid or semi-liquid, eat more fruits and vegetables, drink plenty of water, avoid eating spicy, sour, hemp, spicy, fried foods and eggs, fish, shrimp Such as easy to induce asthma food. Do not eat irritating food. In general, the characteristics of diet should be: diet must be diversified, reasonably matched, nutritious, proportionate, and suitable for digestion and absorption.

4, mentally should maintain a happy and optimistic mood, to prevent mental stimulation and mental over-stress. This requires you to have an open-minded and cheerful attitude towards life. In other words, to maintain a happy spirit, it is necessary to cultivate the idea of "contentment and happiness". However, the pursuit of fame and fortune and enjoyment must be understood as "more than enough, more than enough" Reason, this can feel life and psychological satisfaction. Keep your spirits alive and make your daily life colorful.

5, away from exogenous allergens, such as: some flowers (especially those who are allergic to pollen), bedding, pillows, birds, animals (pets or experimental breeders) filled with items that are allergic to feathers or old cotton wool, Wood (redwood dust, cork processing), sugar processing, mushroom farming, cheese, wine processing, moldy straw exposure, water sources (hot water pipes, air conditioners, humidifiers, saunas) and agricultural pesticides.

Non-specific interstitial pneumonia complications Complications, heart failure, respiratory failure

Mainly complicated by pulmonary fibrosis, respiratory failure and so on. Mostly insidious onset, progressive progressive increase in labor dyspnea is the most common symptom, usually accompanied by dry cough, fatigue. The main signs are shallow breathing, bursting sounds with double lower lungs, cyanotic purpura and clubbing, toe, pulmonary hypertension and right ventricular hypertrophy in the late stage, often died of respiratory failure, heart failure.

Symptoms of non-specific interstitial pneumonia Common symptoms Leukocytosis, erythrocyte sedimentation rate, increased dyspnea

The incidence is mainly middle-aged and elderly, the average age is 46 years old, and the female is slightly more than male. There is no obvious relationship with smoking. The onset is mostly subacute, and a few are insidious. The main clinical symptoms are similar to IPF, but the course is shorter. Exercise dyspnea and cough, about 1/3 of patients have fever, clubbing is rare, about 13%, physical examination can smell double lung bursting voice, some patients have anemia, white blood cells increase, most of the ESR increases CRP positive, a small number of ANA and ds-DNA positive, when the lesion is limited to the lungs, can not find other diseases for the cause of the disease, is idiopathic non-specific interstitial pneumonia (INSIP), other may be related to the cause Factors such as connective tissue disease, inhalation of organic dust, certain drug reactions, and the mechanical phase of acute lung injury are caused by NSIP, a small range.

Non-specific interstitial pneumonia

Bronchoalveolar lavage fluid (BALF) examination has no diagnostic effect on NSIP, but can exclude some diseases, such as infection, tumor, sarcoidosis and some occupational lung diseases. The cells of BALF in 9 patients are classified as: macrophages 39±27.9, Neutrophils 25.0 ± 21.7, lymphocytes 32.3 ± 29.2, usually CD4: CD8 ratio inverted, an average of 0.63, patients with alveolar inflammation-based patients inverted more significantly, up to 0.3 ~ 0.2, BALF with lymphocytosis The response to glucocorticoid therapy is good, and the prognosis is ideal. When neutrophils are elevated, NSIP has entered the stage of pulmonary fibrosis, and the prognosis is poor. BALF examination can only help to evaluate treatment response and prognosis.

1. Conventional chest radiographs are mainly in the middle and lower lung fields and subpleural. The bilateral lungs have a relatively even distribution of interstitial infiltration shadows, which can be ground glass, and appear line-like and reticular or nodular shadows as the disease progresses. However, there are few cell lungs, and even occasionally, the volume of the lungs can be reduced.

2. HRCT is an important means of diagnosing NSIP and is characteristic.

(1) Frosted glass shadow: It is a flaky infiltrating shadow. The vascular texture is visible in the middle and lower lung fields and the pleura. About 80% of patients have such shadows, but rarely the only shadow, more symmetrical. .

(2) Solid shadow: often manifested as small pieces of solid deformation, can be symmetrically distributed, more common in the two middle and lower lungs and subpleural.

(3) reticular and line-like shadows and bronchiolar dilatation, the pleura can be thickened.

(4) Honeycomb change: There are few chances of occurrence. The incidence rate reported in the past is 0 to 25.8%. Even if it occurs, the proportion of the total lesions is small. At the same time, the bronchial vascular bundle is thickened, and the traction bronchiectasis is observed. The lung tissue structure is distorted and these manifestations occur during the fibrosis phase.

From the above imaging findings and IPF is still a clear difference, an experienced doctor combined with clinical, lung imaging, lung function and other IPF diagnosis rate of up to about 90%, atypical IPF or suspected NSIP When you need to organize the evidence, you can diagnose it.

3. Pulmonary function The early lung function of NSIP may not change. With the development of the disease, there are different changes at different stages. As a result, the elastic retraction force of the lung is increased, the lung compliance is decreased, the lung capacity is reduced, the whole lung capacity is reduced, and the airflow speed is decreased. Unobstructed, the result is normal or high FEV1/FVC, gas exchange is impeded, the gas exchange area is reduced due to the destruction of capillaries, the alveolar septum is thickened, the diffusion distance is increased, the dispersion function is decreased, and the V/Q ratio is unbalanced. It is also an important cause of hypoxemia. Arterial blood gas in patients with NSIP shows hypoxemia with increased alveolar oxygen pressure difference (Aa) DO2, and venous blood (physiological shunt) is characteristic, arterial oxygen partial pressure drops. The arterial blood carbon dioxide partial pressure is normal or low, and the change in lung function is specifically related to the severity of lung cell infiltration and pulmonary fibrosis.

Non-specific interstitial pneumonia diagnosis and differentiation

Diagnostic criteria

The diagnosis of NSIP is a difficult problem for clinicians and pathologists. It is difficult to make a correct diagnosis based on clinical symptoms and X-ray imaging findings. When younger patients have atypical IPF, their clinical symptoms and imaging findings should be For lung biopsy, obtain histological evidence, if the fiberoptic bronchoscopy lung biopsy can not obtain enough to provide diagnostic materials, if conditions should be limited to open chest biopsy or thoracoscopic lung biopsy, both lung biopsy should choose fresh lesions The site, that is, the site of inflammation is taken from the living tissue, and the characteristics of the primary disease can be maintained. Generally, 2 to 3 pieces are taken, and the whole tissue can be observed with a diameter of about 1 cm. For example, in a region with dense lesions and obvious fibrosis, It is difficult to distinguish histologically from IPF. The limited open lung biopsy (ie, small incision lung biopsy) incision is only 5-7 cm, with few injuries, short operation time, high positive rate, and no thoracoscopic lung biopsy. Less damage, but it takes longer.

Differential diagnosis

NSIP needs to be differentiated from other types of idiopathic pulmonary interstitial disease.

1. IPF IPF has its special manifestations in clinical symptoms and imaging. It is not difficult to diagnose. When clinical symptoms and imaging are not typical, lung biopsy is needed. IPF has important histological features, and both old and new lesions coexist. Invariably, as well as smooth muscle hyperplasia in fibrotic and cellular lesions, a "fibroblast foci" is seen, characterized by bundles of lightly stained fibroblasts between the mucus matrix, which are arranged parallel along the long axis of the alveolar septum.

2. Idiopathic bronchiolitis interstitial pneumonia (RBILD) / desquamative interstitial pneumonia (DIP) is mostly smokers, more men than women, more common in the elderly, insidious onset Or subacute, progressive dyspnea and dry cough are the main clinical symptoms, some patients have clubbing, clubbing can be relieved after the disease is improved, lung function shows mild restrictive ventilatory dysfunction, imaging DIP early lung It has blurred shadows, ground glass changes, late lines, mesh or net nodules, generally no honeycomb lungs, RBILD is mesh-like, net nodules, ground glass shadows, and pathological features of DIP are lung lesions. Uniform and consistent, a large number of alveolar macrophages accumulate in the alveolar cavity, interstitial inflammation is mild, collagen deposition is not obvious, no typical fibroblastic foci, RBiLD pathological features similar to DIP, but the lesion distribution is patchy, confined to fine In the alveoli around the bronchi, it is not as diffuse and uniform as DIP. There are mucous plugs in the peripheral and respiratory bronchioles, and there is chronic inflammation in the parietal layer. It can be self-healing or obviously improved after smoking cessation. The glucocorticoid is effective. The prognosis is good.

3. Idiopathic obliterative bronchiolitis with organizing pneumonia (BOOP) occurs in 50 to 60 years old, there is no difference between men and women, and there is little relationship with smoking. The incidence is mostly sub-acute, and it can also be attacked insidiously. Have flu-like symptoms, exercise dyspnea, dry cough, less cough or hemoptysis, chest pain, night sweats, etc., rarely appear clubbing, lung function shows mild to moderate restrictive ventilation dysfunction, imaging two The lungs showed multiple plaque infiltration shadows, grinding glass shadows or solid shadows, and bronchial aeration signs were seen in the real shadows. The above is the manifestation of alveolitis. The pathological changes of the lesions are also characteristic of the interstitial inflammation. It is characterized by reticulate, nodular, nodular shadows, but no honeycomb lungs. Occasionally, isolated focal shadows are visible. The edges are clear and there may be voids inside. It may not change for months or years. Lungoscopy lung biopsy, such as granulation tissue formation and mechanical pneumonia changes in the airway below the bronchioles, the diagnosis is basically established, the granulation tissue is composed of loose collagen fibers and muscle fibers, interstitial inflammation is light, if necessary, limited Thoracic lung biopsy Or through thoracoscopic lung biopsy, large tissue can be obtained. The treatment of BOOP is the first choice for glucocorticoids. The curative effect is very good. It can be improved within 24 to 48 hours. It usually takes several weeks for the lung shadow to disappear. Some patients have residual lung lesions. Can not be completely absorbed.

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