OVERVIEW
Pulmonary hemorrhage-renal syndrome may be caused by viral infection and/or inhalation of certain chemical substances that cause primary lung damage. Secondary renal injury can occur due to the presence of cross-reactive antigens in the basement membranes of alveolar wall capillaries and glomerular basement membranes. The disease is most common in young males, with a male-to-female ratio of 9:1, and is rare in patients under 16 years of age.
Etiology
The cause of the disease is not known. It may be related to viral infection, or it may occur after allergic to some drugs such as penicillamine. Occasionally, it may occur after heavy metal poisoning, scleroderma, hepatitis and macroglobulinemia.
Symptoms
Many patients have respiratory tract infection before the onset of hemoptysis, and then there are repeated hemoptysis, most of them appeared before the renal lesions, the course of the disease, the long years, the short months, and a small number of people after nephritis.X-ray examination shows that there are diffuse or nodular shadows in both lungs, spreading from the lung door to the periphery, and the tip of the lungs and the proximity to the diaphragm are clearly defined, and it is often heavier on one side, and some people do not have a history of hemoptysis, but there is a hemorrhage confirmed by the sputum with hemosiderin and the chest radiographs. In hemoptysis lung diffusion function is reduced, hypoxemia occurs, anemia is common.
Examination
1. General examination
Normally, it should include blood routine, blood biochemistry, renal function, arterial blood gas analysis, urine routine, etc.
2. Serologic examination
Primary tests may include antinuclear antibody (ANA) profile, anti-double-stranded (ds) DNA, anti-neutrophil cytoplasmic antibody (ANCA), anti-basement membrane (GBM) antibody, and antiphospholipid antibody. patients with SLE may have high titers of ANA and dsDNA and reduced complement levels. circulating anti-GBM antibodies are positive in Goodpasture syndrome. ANCA include perinuclear (P-ANCA) and cytoplasmic. -ANCA), antibodies against myeloperoxidase (MPO), elastase, and lactoferrin, and antibodies against serine protein 3 (PR3), which is distributed in the cytoplasm and is known as C-ANCA. microscopic polyarteritis, Churg-Strauss vasculitis, and oligoimmune glomerulonephritis (PIGN Microscopic polyarteritis, Churg-Strauss vasculitis, and oligoimmune glomerulonephritis (PIGN) may be positive for P-ANCA.
3. Histologic examination
The choice of biopsy site depends on the specific disease. For example, if Weil’s granulomatosis is diagnosed, a nasal or sinus biopsy may be performed, which has a higher diagnostic value.
4. Kidney biopsy
In addition to routine light microscopy, direct immunofluorescence staining is usually required. In immune-mediated alveolar hemorrhagic syndrome with concomitant renal involvement, the renal pathology is necrotizing glomerulonephritis, with varying degrees of histologic changes, ranging from mild thickening of the peritubular membranes to severe crescentic glomerulonephritis, and rarely renal arterial vasculitis. Immunofluorescence staining of various diseases has different manifestations, anti-basement membrane antibody (ABMA) disease has wired deposits along the glomerular basement membrane, collagen vascular disease and idiopathic immune complex-mediated glomerulonephritis have granular deposits, while immunofluorescence testing of PIGN is negative, and the combination of serologic ANCA, ABMA, ANA and other tests can enhance the significance of the diagnosis, treatment and prognosis.
5. Tracheoscopy
Tracheoscopy and alveolar lavage (BAL) can help to confirm the diagnosis of alveolar hemorrhage and exclude hemorrhage caused by infection and localized airway pathology, thus helping to make a differential diagnosis and find the cause of the disease. According to the gradual increase in the degree of bloodiness of the recovered fluid in BAL, active hemorrhage can be affirmed. In addition, the discovery of ferritin-containing cells by microscopic examination is also of value in affirming alveolar hemorrhage.
6. Lung biopsy
Transbronchial lung biopsy is of limited diagnostic value in DAH, and open lung biopsy is required to clarify the cause of the disease. Lung biopsy is only suitable for patients whose etiology is not clear after routine examination, and whose condition is relatively stable and can tolerate unilateral lung atrophy. Open lung biopsy is not indicated in patients with severe pulmonary hemorrhage and expiratory failure. Infection and pneumothorax can occur after lung biopsy.
Diagnosis
1. pulmonary hemorrhage with linear deposition of IgG in the alveolar basement membrane.
2. acute nephritic syndrome, massive crescent formation in the kidney (extracapillary proliferative nephritis) may be accompanied by capillary necrosis GBM with IgG line-like deposition.
3. Positive serum anti-GBM antibody.
Differential diagnosis
1. Pulmonary renal syndrome
In addition to pulmonary hemorrhage- nephritis syndrome, there are many other diseases that can cause pulmonary renal syndrome, such as ANCA-related systemic vasculitis, SLE, and nephritis caused by infection. In addition, hemoptysis can also occur in pulmonary embolism caused by renal vein thrombosis, and congestive heart failure caused by end-stage renal failure.
2. Lupus nephritis
When this disease manifests acute nephritis, acute renal failure with pulmonary hemorrhage can occur, which can be easily confused with pulmonary hemorrhage- nephritis syndrome. However, this disease is mostly seen in young women, usually with skin, joints and other systemic damage serum immunological examination can help diagnosis.
3. Small vessel vasculitis nephritis
This type of disease can be similar to pulmonary hemorrhage- nephritis syndrome because of its pulmonary hemorrhage manifestations. However, the disease is most common in middle-aged and elderly people aged 50 to 70 years, with fatigue, low-grade fever, weight loss and other systemic symptoms obvious blood anti-neutrophil cytoplasmic antibody positive. Wegener’s granulomatosis can be interstitial inflammation, the two can occasionally coexist.
4. Acute nephritis with left heart failure
This disease may have bloody sputum and dyspnea similar to pulmonary hemorrhage – nephritis syndrome, but the disease is more common in adolescent patients. There is a history of streptococcal infection, often due to severe hypertension, sodium retention and edema, congestive heart failure, renal biopsy can be differentiated.
5. Acute nephritis
In addition to anti-GBM nephritis, immune complex nephritis and cellular immune vasculitis can also cause typical crescentic nephritis and acute renal failure.
6. Idiopathic pulmonary ferritinosis
The hemoptysis sputum ferritin-containing cells and lung X-ray manifestations of this disease are very similar to pulmonary hemorrhage – nephritis syndrome. However, this disease mostly occurs in adolescents under 16 years of age, with slow progression and good prognosis, and lung and renal biopsy can help to identify it.
Complications
The main complication is pulmonary hemorrhage, which can be life-threatening in severe cases. Iron-deficiency anemia can occur with massive or persistent bleeding. Renal damage can be oliguria or anuria, serum creatinine concentration rises rapidly, renal damage is progressive, within a few months to uremia. Individual cases may transform into other types of renal disease.
Treatment
The key to treatment lies in early diagnosis, timely removal of causative factors and effective treatment.
1. General treatment
To strengthen nursing care, pay attention to keep warm, prevent and control colds, quit smoking, reduce and avoid various possible causative factors such as co-infections, often repeated aggravation of lung lesions must be early and active use of antibacterial drugs to prevent and control secondary infections aggravate the condition, the clinic shows that the third generation of broad-spectrum cephalosporins, ceftazidime (cefotaxime) efficacy is satisfactory. Severe and persistent hemoptysis can lead to severe iron deficiency anemia should be corrected, can be supplemented with iron, commonly used ferrous sulfate, folic acid, vitamin B12; if necessary, transfusion of fresh blood.
2. Adrenocorticotropic hormone and immunosuppressants
Combined application of adrenocorticotropic hormone and immunosuppressant can effectively inhibit the formation of anti-basement membrane antibody, which can rapidly reduce the severity of pulmonary hemorrhage and control the life-threatening hemoptysis. Methylprednisolone (methylprednisolone) shock therapy is usually used, with the dose gradually reduced after 2 months of intensive treatment and maintained for at least 3 to 6 months. This treatment can also prevent the feedback anti-GBM antibody synthesis hyperactivity after plasma exchange, if at the same time add the immunosuppressant cyclophosphamide or azathioprine efficacy is better. It is also possible to start oral prednisone (prednisone) and then add immunosuppressant, after the control of the disease, stop using the immunosuppressant prednisone (prednisone), slowly reduced to the maintenance amount to continue oral treatment, the whole course of treatment for half a year to 1 year.
3. Plasma exchange and immunosorbent therapy
Plasma exchange or immunosorbent can remove anti-GBM antibody, active plasma exchange therapy, combined with the application of immunosuppressant and medium-dose corticosteroid therapy can effectively stop pulmonary hemorrhage and improve renal function, combined with oral prednisone (prednisone) and the use of high-dose cytotoxic drugs (mainly cyclophosphamide).
4. Anticoagulation and fibrinolytic therapy
Because fibrin-associated antigens appear at the site of damage, anticoagulants with corticosteroids and cytotoxic drugs are theoretically beneficial in the treatment of this disease, but studies have failed to prove this.
5. Renal replacement therapy
For patients who have entered end-stage renal disease and are on hemodialysis or abdominal dialysis because conventional treatment is ineffective or delayed, renal transplantation may be considered if the condition is stable and the circulating anti-basement membrane antibodies in the blood are reduced to undetectable levels.
6. Other
For patients diagnosed with this disease, if renal biopsy proves irreversible damage, and it is difficult to control pulmonary hemorrhage with high-dose hormone shock therapy and plasmapheresis, bilateral nephrectomy can be considered, and renal function can be replaced with dialysis treatment. Those who are at risk of aggravating pulmonary hemorrhage during the course of treatment should not be treated with anticoagulant and antiaggregant therapy, and supportive therapy should be strengthened and secondary infection should be prevented.