Malaria nephropathy

Introduction to malaria nephropathy In China, the incidence of malaria is quite extensive, and vivax malaria, falciparum malaria or three-day malaria can occur in different regions, and is highly prevalent in the south of 25 degrees north latitude. The development of China's highly endemic areas has been basically controlled, and the incidence rate has been significantly reduced. The main clinical manifestations of malaria nephropathy are hypertension, proteinuria, hematuria and edema. All four malaria cases can be complicated by this disease, but it is more common in Malaria. basic knowledge The proportion of illness: 0.001% Susceptible people: no special people Mode of infection: contact spread Complications: Hypertension, proteinuria, hematuria, edema, splenomegaly, hepatomegaly

Causes of malaria nephropathy

(1) Causes of the disease

Humans are generally susceptible to several human malaria parasites. Plasmodium infection is the only cause of this disease. It is found that the incidence of kidney disease in malaria endemic areas is much higher than that in non-endemic areas during the same period. In recent years, clinical and histological studies have been conducted in patients. Plasmodium antigenic material in the immune complex in the glomerulus further confirms that malaria is an important cause of kidney disease.

(two) pathogenesis

Kidney damage caused by malaria can be divided into acute renal failure, acute reversible renal damage and chronic progressive renal damage. Acute renal failure is one of the serious complications of falciparum malaria, and its incidence rate is about 0.45%. The onset is associated with acute intravascular hemolysis, decreased blood volume, increased blood viscosity, and diffuse intravascular coagulation, while the latter two are closely related to immune response.

Acute renal failure

Acute renal failure caused by malaria, the pathological changes are mainly distal tubule degeneration and necrosis, hemoglobin tube type and granular tube type in the lumen, renal interstitial edema, falciparum malaria acute renal failure is often non-oliguric Therefore, it is easily overlooked in the clinic. The common cause is acute intravascular hemolysis (black water fever), which is common in falciparum malaria. Congenital glucose-6-phosphate dehydrogenase (G-6-PD) deficiency is Important factors, the release of malaria paratoxin and the application of antimalarial drugs (such as quinine and primaquine), antipyretic analgesics, etc. are all causes, acute patients with acute renal failure.

2. Acute reversible renal damage

Under immunofluorescence, IgM (mainly) can be seen. IgG and C3 are deposited in the subendothelial and mesangial areas of the basement membrane. Electron microscopic deposits can be seen under electron microscopy. Some of the Plasmodium antigens can be found. Some people found that after implantation of falciparum malaria antigen, The circulating antibody then binds to it and forms an immune complex in situ, indicating that kidney damage in humans and experimental animals is caused by immune complexes, which are common in most malaria patients (eg proteinuria, glomeruli) Nephritis and nephrotic syndrome, etc.) are effective against malaria treatment.

Renal biopsy showed thickening of the mesangial membrane, proliferation and hypertrophy of the endothelial cells, and irregular thickening of the basement membrane.

3. Chronic progressive renal damage

Chronic progressive renal damage caused by malaria can also detect Plasmodium antigen in kidney tissue. In the 1960s, renal damage was confirmed to be due to immunological abnormalities induced by Plasmodium infection, leading to immune complex nephritis. It is believed that the three-day malaria nephropathy may be an autoimmune reaction. In the early stage, the immune complex is formed by the circulating three-day malaria antigen, or the antigen is implanted into the renal capillary wall, and the immune complex is formed in situ in combination with the antibody. The initial damage of the kidney, and then the damaged kidney tissue protein can act as an autoantigen, promote the production of autoantibodies, and then cause immune complex nephritis, the anti-nuclear antibody of the residents of the three-day malaria endemic area and the anti-nucleus of Plasmodium vivax Antibodies have a cross-immunological response.

Malaria prevention

1. Actively treat the source of infection. Commonly used drugs mainly include hydroxyquine, pyrimethamine, and pyrrolidine. In addition, Changshan, Artemisia annua, Bupleurum and other traditional Chinese medicines have a good effect on malaria treatment. These drugs should be used by doctors according to the type and condition of the malaria parasite. The dosage and usage are not easy to grasp. Do not eat it yourself. In addition, patients should be treated for rest periods, that is, those who had had malaria in the previous year, and then treated with primaquine, given an 8-day dose to prevent recurrence.

2. Completely eliminate Anopheles mosquitoes. The main measures are to improve environmental sanitation, including clearing sewage, reforming rice paddy irrigation methods, developing ponds, rice-fish farming, and spraying insecticides indoors and in livestock sheds.

3. Do a good job of personal protection. Including personal hygiene, not sleeping outdoors in the summer, it is best to hang mosquito nets when sleeping; go out during the day, apply some anti-mosquito cream on the exposed parts of the body to avoid mosquitoes.

4. Improve the population's resistance to disease Malaria vaccination may reduce the incidence and mortality of this disease, but due to the diversity of Plasmodium antigens, it will bring greater difficulties to the development of vaccines. The main developments are sporozoite proteins and genetic vaccines, which have not yet been available for field application.

Malaria vaccines, AIDS vaccines and tuberculosis vaccines have become the top three vaccines in the world. China's self-developed "recombinant malaria vaccine" has been approved by the State Drug Administration and the World Health Organization to enter clinical trials. Chemical drug prevention is a commonly used measure at present. Healthy and foreign populations in high malaria areas may be selected as appropriate. With the effective prevention and treatment of various types of malaria, kidney damage caused by malaria will be controlled.

Malaria nephropathy complications Complications hypertension proteinuria hematuria edema splenomegaly

1. Black urine fever This is a sudden acute hemolysis in falciparum malaria patients, accompanied by a serious complication of hemoglobinuria and hyperthermia, which is more common in cases of falciparum malaria that repeatedly and repeatedly take quinine.

2. Malaria nephropathy with hypertension, proteinuria, hematuria and edema as the main clinical manifestations, four malaria can be complicated by this disease, but more common with three-day malaria.

3. Splenomegaly, large liver, blood cell changes, pseudo acute abdomen, etc. are also common complications.

Malaria nephropathy symptoms Common symptoms Urinary frequency urgency and periodic chills fever... Proteinuria weakness, ascites, chills, fatigue, intermittent chills, urine, red sauce or soy sauce

1, the main clinical manifestations of malaria nephropathy are hypertension, proteinuria, hematuria and edema, four malaria can be complicated by this disease, but more common with three-day malaria.

2, patients with acute renal failure caused by malaria, may have high fever, a lot of sweating, insufficient intake of water leads to a decrease in effective blood volume, followed by increased compensatory sympathetic activity, increased secretion of catecholamines, strong contraction of renal blood vessels, leading to kidney Significantly reduced blood flow can cause or aggravate renal insufficiency.

3, chronic progressive renal damage caused by malaria, the main clinical manifestations of nephrotic syndrome, most patients died within 1 year, the mortality rate is high (about 13%), usually three-day malaria complicated with nephrotic syndrome, more common in In children, typical renal edema occurred within 3 weeks after the control of malaria, and even pleural effusion, ascites, liver, splenomegaly and anemia were present. After edema subsided, proteinuria and renal function damage persisted. And high blood pressure, a small number of progressive renal failure.

Malaria nephropathy check

1. Blood pathogen examination

The four malaria parasites in the human body are only falciparum malaria. Only the ring body and gametophyte are seen in the surrounding blood, and there are more chances to be detected during the attack. Most of the protozoa enter the visceral capillaries during the intermittent period. If the gametophyte has not yet appeared, the blood test It may be temporarily negative, so it is most appropriate to check blood during the onset of falciparum malaria; the blood tests of the other three malaria are not limited by time, and the protozoa can be seen in both the attack and intermittent periods, so the clinical symptoms resemble malaria, blood test protozoa Those who are negative should adhere to the examination for several days, check the blood twice a day, and carefully examine the thick blood membrane according to the regulations. The power is much higher than that of the thin blood film. Any malaria will eventually find the malaria parasite in the surrounding blood. Blood smears, staining, and microscopy are taken from the earlobe or fingertips of the patient. It is still the most reliable method for the diagnosis of malaria. If the intra-erythrocytic parasite is found, it can be diagnosed.

In view of the accuracy of the microscopic examination method, the traditional blood test method has been improved in recent years due to the density of protozoa in the blood, the production and dyeing techniques, the deformation or density of protozoa after taking the drug, and the experience of microscopic examination. One is to use a capillary containing anticoagulant and acridine orange, take 60l of blood from the patient, and after centrifugation with a floater, the Plasmodium is concentrated in the upper layer of red blood cells and the lower layer of white blood cells. The two layers of cells are present due to the presence of a buoy in the center of the tube. And the Plasmodium is pushed to the wall of the tube, and the fluorescent malaria parasite can be directly examined under a fluorescence microscope. This method has a concentration effect to improve the sensitivity, and the second is to replace the ordinary water hemolysis with a 0.5% to 1.0% saponin solution, and then Microscopic examination after staining with Gibber's solution has the advantage that the thick saponic layer treated with saponin is clear, free of red blood cell debris and platelet interference, and helps the malaria parasite to be detected.

2. Immunological testing

Detection of Plasmodium antigens and antibodies, the main methods are agarose diffusion test, convective immunoelectrophoresis, enzyme-linked immunosorbent assay, direct fluorescence or enzyme immunostaining; etc.; can detect protozoa, can be used for clinical diagnosis, epidemiology Investigate, trace the source of infection, assess the efficacy and determine the level of malaria by measuring the level of antibody in the epidemic area; screen the blood donor to prevent malaria transfusion infection, and evaluate the effects of antimalarial measures, in addition to multiple episodes If the cause is not ascertained, the detection of malaria antibodies is helpful for diagnosis, and the methods for detecting antibodies are indirect fluorescent antibody test, indirect hemagglutination test, and enzyme-linked immunosorbent assay.

3. Nucleic acid probe detection

At present, there are several different nucleic acid probes for the detection of Plasmodium at home and abroad. Due to its unique high specificity, the sensitivity can be higher than the microscopic examination. It is considered that the nucleic acid probe technology is very promising to replace the conventional microscopy, and A large number of samples can be processed in batches in a short period of time. It has been considered to be able to quantify and estimate the level of malaria parasitemia. It is a potential diagnostic tool for malaria epidemiological investigation and evaluation of antimalarial measures.

4. PCR detection

Among the various malaria detection methods, the sensitivity and specificity of the PCR method are the highest, in order to further improve the sensitivity and specificity of the PCR technology, and to facilitate the promotion in practice, nested PCR (nested PCR) In addition to being able to directly detect Plasmodium in anticoagulant samples, the PCR detection of Plasmodium on the dried blood droplets of filter paper has also matured, which facilitates the monitoring of malaria in remote areas by PCR technology. The requirements for experimental techniques and conditions are high, which limits its application in the field. For the current conditions of most malaria areas, after the blood collection on site, it is necessary to return to the laboratory with better conditions for further analysis and treatment.

5.Dipstick method

The sensitivity of this method for diagnosing malaria (84.2% to 93.9%) and specificity (81.1% to 99.5%) are both high; and it is easy to operate, fast and stable, and easy to learn, but the Dipstick method also has certain limitations. It is difficult to detect Plasmodium falciparum that is still in the latent period or contains only mature gametophytes in this blood.

6. In acute renal injury , due to distal tubule degeneration and necrosis, examination showed hemoglobin tube type and granular tube type in the lumen, renal interstitial edema, patients may have a large amount of proteinuria and red, white blood cell urine and tubular urine, Most of them are non-selective proteinuria, decreased serum albumin, increased 2 globulin, elevated cholesterol, decreased C3 and other glomerulonephritis and nephrotic syndrome. Patients may also have symptoms of increased blood viscosity due to malaria. Protozoa's red blood cell surface has fibrin deposition, which causes them to adhere to each other, causing microcirculatory disorders, eventually leading to renal failure and disseminated intravascular coagulation (DIC).

Acute reversible renal damage renal biopsy showed glomerular mesangial thickening, endothelial cell proliferation and hypertrophy, irregular thickening of the basement membrane, under immunofluorescence, IgM (mainly), IgG and C3 under the basement membrane and Mesangial area deposition, electron dense deposits under electron microscopy, and some Plasmodium antigens can be found.

The pathological changes of the three-day malaria kidney are focal (about 30%) or diffuse thickening of the glomerular capillary wall, and segmental sclerosis around the capillary vasospasm and mesangial cells (30% to 75%). Mainly, the basement membrane is thickened, and some cases have a small amount of crescent formation. The lesion progresses progressively to the whole glomerular sclerosis (about 75%), and secondary to tubular atrophy, which is characterized by thickening of the capillary wall. Stenosis and occlusion of the lumen, tubular atrophy and significant interstitial infiltration.

Immunofluorescence microscopy mainly involves IgM deposition in the mesangial area. In addition, there are a small amount of IgG, C3, and IgA can be found. Immunoglobulins appear more than 1 week after the onset of the disease, lasting for half a year. In recent years, the thickness of sediment particles is considered to be IgG subtypes, coarse particles often contain IgG3, fine particles often contain IgG2, under electron microscopy, there is deposition of basal membrane under the glomerular endothelium, and electron-dense deposits in the basement membrane.

Diagnosis and identification of malaria nephropathy

diagnosis

1. Diagnosis of malaria

The four types of malaria in the human body have many commonalities in clinical manifestations, course of disease, and drug response, and each has certain specificities. Therefore, the diagnosis should identify the type of malaria in patients. The clinical diagnosis points are:

(1) Most cases have chills or chills of varying lengths before fever.

(2) The body temperature rises rapidly in a short time, lasts for several hours, then falls quickly, and then there are different degrees of sweating. The body temperature is measured once every 2 to 4 hours, and the body temperature curve is analyzed, then the body temperature at night is often lowered. To normal or below normal temperature.

(3) There is a timing of seizures, and the fever period and the non-heat period overlap, and there is a certain regularity.

(4) The patient feels good in the period of seizure, fatigue, weakness and slight discomfort.

(5) The incidence is more common around noon and afternoon, and fewer authors start at night.

(6) The clinical symptoms are more serious than once, and after repeated attacks, they gradually reduce, and there is a tendency of self-healing.

(7) The clinical manifestations of hemolytic anemia, the degree of which is consistent with the number of episodes.

(8) Splenomegaly, the degree is related to the course of the disease, and some cases also see liver enlargement.

Infants and young children, falciparum malaria, and new infections first and second, the clinical symptoms are often atypical. In addition, some patients with higher immunity have a large number of protozoa in the blood, but the clinical symptoms are not obvious or not at all. In particular, medical examinations and laboratory tests are required to determine the diagnosis. For example, laboratory tests can detect the presence of the malaria parasite in the surrounding blood.

2. Diagnosis of malaria nephropathy Malaria in the course of seizure complicated by glomerulonephritis, acute renal failure or nephrotic syndrome, is generally considered to be an immunopathological phenomenon, is type III allergic reaction, nephropathy caused by acute malaria is a temporary Reversible lesions, patients may have hemolytic anemia, jaundice, backache, frequent urination, urgency, etc., urine test can be seen in urine red sauce or soy sauce color, long-term unhealed part of patients, can appear nephrotic syndrome, malaria nephropathy malignant Malaria and three-day malaria patients are more common, combined with the diagnosis of clinical malaria, and the clinical manifestations of nephropathy, a comprehensive analysis of laboratory tests can confirm the diagnosis.

Differential diagnosis

Clinical manifestations of typical malaria, diagnosis is not difficult, for the so-called atypical cases accounting for more than 1/3, must be differentiated from other diseases characterized by fever, splenomegaly and hepatomegaly, so as not to delay treatment, spread malaria, or neglect Other diseases in which malaria coexists.

1. Acute schistosomiasis has a history of exposure to schistosomiasis and a history of dermatitis, common digestive symptoms such as diarrhea and mucous membranes, and dry cough. Unlike malaria, more than 90% of the liver is large. More significant, increased white blood cell count, eosinophilia, cerebral palpebral reaction, ring egg precipitation test or stool incubation positive.

2. Most of the filariasis has a history of previous episodes, white blood cells and eosinophils, no anemia and splenomegaly, and blood microbes are more positive than sputum.

3. Black fever has a history of living in the epidemic area of kala-azar, fever is generally irregular, and can develop into a complete blood cell reduction in the later stage, nose bleeding or gum bleeding, liver and spleen, bone marrow puncture can be found in Lidu body.

4. Amoebic liver abscess liver is obviously swollen and painful, no spleen, irregular heat type, white blood cells increased significantly, mainly neutrophils, ultrasound and X-ray examination can find abscess.

5. Typhoid fever is a heat retention, with rash symptoms such as rose rash, abdominal distension and other symptoms of systemic poisoning, blood, bone marrow, stool and other bacterial cultures and typhoid serum agglutination reaction.

6. Septicemia has irregular body temperature, and white blood cells and neutrophils are significantly increased. Generally, the cause of infection can be found, and blood or bone marrow bacteria culture is positive.

7. Brucellosis fever is periodic, the general symptoms are not heavy, a series of neurological symptoms can be seen later, and intradermal and serological tests can be performed.

8. The body temperature of leptospirosis is continuous heat or relaxation heat, with conjunctival hyperemia, gastrocnemius pain, lymph node swelling, skin mucosal hemorrhage, liver function damage and lung symptoms, etc., can be tested for serum immunology and examination. Leptospira is diagnosed and penicillin is effective.

9. Acute pyelonephritis fever is irregular, with backache, frequent urination, urgency and dysuria, urine test, red, white blood cells and protein, positive bacterial culture, but no clinical symptoms and history of primary malaria, can be identified.

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