Lupus nephritis

　　本病是机体对内源性（自身）抗原所发生的免疫复合物性疾病，并伴有T细胞功能紊乱。本病患者血清中可查得多种抗自体组织成分的抗体，其中抗DNA抗体，尤其是抗双链DNA（天然DNA）抗体的作用较肯定，患者循环免疫复合物可分离成天然及单链DNA抗体及抗原；由患者肾小球上洗脱的免疫球蛋白抗体可与天然及单链DNA抗原结合。

　　一、体液免疫的变化

　　其中DNA和抗DNA抗体形成免疫复合物起主要作用。

　　1、病毒触发因素：较多的研究证实本病与一种RNA病毒——C型病毒有关。C型病毒一方面可能损害组织细胞，使之释放出DNA具有抗原性；另一方面可能由于这种病毒具有逆转录酶，使病毒本身的RNA复制成DNA，而使人体产生的抗DNA抗体，既抗病毒复制产生的DNA，又抗人体DNA。

　　2、细菌内毒素及脂多糖触发因素：有人将细菌的脂多糖成分注入小鼠，观察到可促使小鼠组织的DNA向血循环释放，并具有分裂素的作用，促进B淋巴细胞活化，产生抗体，从而认为此类物质有促进DNA抗原抗体复合物生成的作用。

　　3、自体组织破坏释放DNA：本病患者体内存在着淋巴细胞的细胞毒性抗体。中等分子量的可溶性DNA免疫复合物经过血液循环至肾脏（或其他脏器）而沉积于肾小球。

　　二、细胞免疫

　　抑制性T细胞功能及数量下降。其原因是患者血清中存在着细胞毒抗体（抗淋巴细胞或胸腺细胞抗体），从而破坏了T细胞。抑制性T细胞下降，一方面可直接减小对抗体形成的抑制，另一方面可能因释放淋巴因子以灭活辅助性T细胞的能力下降，而辅助性T细胞促进抗体产生的能力增加，总的使机体体液免疫（抗体生成）旺盛。

　　三、遗传因素的影响

　　本病患者中有相同疾病家族史者占0.4％～3.4。

　　1、过敏

　　本病易发生药物过敏，且表现较重，一旦过敏则不容易逆转或病情恶化，有时疾病处于相对稳定期，接受致敏的药物即可引起病情急性发作如持续性高热等，容易引起过敏的药物常见者有：青霉素类、头孢菌素类、磺胺类、雌激素、普鲁卡因胺、苯妥英钠等，故狼疮病人禁用以上药物。

　　Some cases are prone to allergies to certain foods, and the harm to the condition is similar to that of the above drugs. Especially, it is easy to have allergies to animal meat, such as dog meat, horse meat, lamb, etc., so patients should be advised to eat carefully to avoid exacerbating the condition.

　　2. Infection

　　It is a common complication and the most common cause of death and the main factor for the deterioration of the disease. The reason for the susceptibility to infection is related to the long-term use of immunosuppressants, uremia, and the low immune function of the disease itself. Pneumonia, pyelonephritis, and sepsis are the most common complications. The causative bacteria can be Staphylococcus aureus, Nocardia, Escherichia coli, Proteus, tuberculosis, Cryptococcus, and viruses, etc. 

　　1. Medical history and symptoms

　　Common in middle-aged and young women, mild cases may be asymptomatic proteinuria (<2.5g/d) or hematuria, without edema, hypertension; most cases may have proteinuria, red and white blood cell urine, cast urine, or nephrotic syndrome, accompanied by edema, hypertension, or decreased renal function, increased nocturia is common; a few cases may have an acute onset, rapid deterioration of renal function, most of which occur after fever, arthritis, rash, and other extrarenal manifestations. In severe cases, the lesions often rapidly involve serous membranes, heart, lungs, liver, hematopoietic organs, and other organ tissues, accompanied by corresponding clinical manifestations. About 1/4 of patients present with kidney damage as the first manifestation. For women of childbearing age with kidney disease, routine examination of immune serological indicators related to the disease should be performed. The diagnosis of this disease mostly refers to the 1982 diagnostic criteria for systemic lupus erythematosus established by the American College of Rheumatology.

　　2. Physical examination findings

　　Fever is common in the acute stage; most patients have anemia; butterfly-shaped facial rash is a characteristic change, which may be accompanied by joint redness and swelling, alopecia, rash, heart murmur or pericardial effusion, enlargement of the liver and spleen, enlargement of lymph nodes, and varying degrees of edema or pleural effusion and abdominal effusion.

　　1. Pay attention to physical factors

　　The incidence of systemic lupus erythematosus among close relatives is as high as 5% to 12%, and the incidence among identical twins is as high as 69%. The incidence of other autoimmune diseases such as rheumatoid arthritis, dermatomyositis, scleroderma, sicca syndrome, and psoriasis in lupus patients' relatives is also high, and the incidence among blacks and Asian descendants is higher than that among whites, all of which suggest that lupus is influenced by genetic factors. Women are more susceptible, and the low testosterone level in patients indicates endocrine factors, especially the level of estrogen in the body of lupus patients is related to the onset of lupus nephritis. Therefore, lupus patients with a history of autoimmune disease, including those with autoimmune diseases in their relatives, should be highly vigilant. Once they fall ill, they should consider autoimmune diseases, and once they have autoimmune diseases, they should be treated actively to prevent the occurrence of lupus nephritis and subsequent kidney damage.

　　2. Actively treat viral infections

　　Recent experimental research has found that viral infection may be related to the occurrence of systemic lupus erythematosus. Therefore, we should actively treat various viral infections. Especially for such "minor diseases" as upper respiratory viral infections, we must not take them lightly. Because "wind is the root of all diseases", many serious diseases start with common colds and flu as the initial cause of harm to the population.

　　3, Pay attention to drug toxicity

　　Drugs related to lupus erythematosus include hydralazine, procainamide, isoniazid, methyldopa, chlorpromazine, and quinidine, among which the first two are more common. It may be related to the hydrazine, amine, and thiol groups in the drug. Therefore, for lupus erythematosus patients with a lupus genetic background, attention should be paid to the potential toxicity of these drugs to lupus erythematosus patients.

　　4, Avoid sunlight exposure

　　Ultraviolet radiation can worsen the condition of lupus nephritis, which is relatively common. Because ultraviolet light can convert DNA into thymine dimers, enhancing antigenicity and promoting the occurrence of systemic lupus erythematosus. Therefore, lupus nephritis patients should avoid long-term exposure to strong sunlight in daily life to reduce kidney damage caused by excessive ultraviolet radiation.

　　1, Urinalysis may show varying degrees of proteinuria, microscopic hematuria, leukocytes, erythrocytes, and cast urine.

　　2, Most patients have moderate anemia, occasionally hemolytic anemia, decreased blood leukocytes, and platelets less than 100×10^9/L, with a faster erythrocyte sedimentation rate.

　　3, Immunological examination: positive for multiple autoantibodies in serum, significantly increased gamma globulin, positive for circulating immune complexes, hypocomplementemia, especially in the active phase, positive for lupus erythematosus cells in blood, and positive for lupus band test on the skin.

　　4, Severe active lupus nephritis is accompanied by reversible Ccr decreasing to varying degrees, with elevated blood urea nitrogen and creatinine, decreased blood albumin, or increased liver function transaminase; in the terminal stage of lupus nephritis, Ccr decreases significantly and blood creatinine and urea nitrogen increase significantly.

　　5, Imaging examination: B-ultrasound showing enlargement of the kidneys suggests acute lesions; some patients have liver, spleen enlargement, or pericarditis.

　　Renal biopsy can understand the pathological type, the activity of the lesions, and determine the treatment plan. For systemic lupus erythematosus with kidney damage as the first manifestation, renal biopsy is helpful for diagnosis.

    The diet of lupus nephritis patients should be light and easy to digest, with an emphasis on eating more vegetables and fruits, and a reasonable diet should be balanced. In addition, patients should also pay attention to avoiding spicy, greasy, and cold foods.

　　The treatment of lupus nephritis is based on clinical manifestations, laboratory findings, and renal biopsy data. For mild systemic lupus erythematosus (such as only rash, low fever, or joint symptoms), and abnormal immunoserological examination, if urinalysis is normal and renal biopsy shows normal glomeruli or slight lesions, non-steroidal anti-inflammatory drugs may be used to improve symptoms; in general, it is not necessary to use glucocorticoids or cytotoxic drugs, and the disease progression should be closely monitored. If urinalysis is abnormal and renal biopsy shows focal segmental glomerular mesangial proliferation with segmental necrosis, crescent formation, and focal glomerulosclerosis, medium to low doses of glucocorticoids (such as prednisone 20-40mg/d) may be used, and cytotoxic drugs or tripterygium preparations may be added as appropriate.

　　2. Severe systemic lupus erythematosus (such as high fever, joint pain, weakness, and/or rapid involvement of serous membranes, heart, lungs, liver, hematopoietic organs, and other organ tissues) with acute nephritis syndrome or rapidly progressive nephritis syndrome, renal biopsy showing diffuse proliferative glomerulonephritis or crescentic glomerulonephritis, progressive decline of renal function, should be given standard hormone treatment plus CTX pulse therapy; or methylprednisolone pulse therapy, 1.0g per day, intravenous injection for 3-5 days as a course, followed by moderate dose prednisone maintenance, and can be repeated once every 7-10 days if necessary, generally not more than 3 courses. When the above methods are not effective or the condition is severe, plasma exchange therapy can be considered; for those who cannot use CTX, cyclosporine A, mycophenolate mofetil, and other drugs can be tried. In cases with acute severe renal insufficiency, severe hypercapnia, and heart failure, emergency dialysis should be performed to help them through the dangerous period, creating conditions for drug treatment and gaining time.

　　3. For patients with asymptomatic proteinuria (urinary protein > 2g/24h), corticosteroids can be used, and cytotoxic drugs can be added according to circumstances; for patients with asymptomatic hematuria, tripterygium glycosides preparation (conventional dose or double dose) or CTX can be used. Those who have the conditions should choose medication based on renal pathological type.

　　4. For patients with nephrotic syndrome but few red blood cells in the urine, stable renal function, or renal biopsy showing membranous lupus nephritis, prednisone 0.8-1.0mg/kg.d should be preferred. If the effect is not good after 2-4 weeks, add CTX. If accompanied by renal function decline, severe hypertension, renal biopsy showing significant glomerular hyperplasia or pathological type transformation, then standard hormone treatment plus CTX pulse therapy should be given.

　　5. For patients with stable proteinuria without systemic lupus erythematosus manifestations, or azotemia with renal pathology mainly showing chronic changes, it is generally not recommended to use prednisone and cytotoxic drugs for a long time.

　　6. End-stage lupus nephritis should be treated as chronic renal failure.

　　7. General treatment includes rest, diet, diuresis, hypotension, anticoagulation, and prevention and treatment of various complications, and should refer to the treatment of primary glomerular diseases according to the patient's condition.

　　8. The differentiation and treatment of traditional Chinese medicine and Chinese herbs can improve efficacy, reduce symptoms, and reduce the side effects of Western medicine.