Chronic pyelonephritis

Introduction to chronic pyelonephritis Chronic pyelonephritis is a chronic inflammation caused by bacterial infection of the kidney. The lesion mainly affects the renal interstitial and renal pelvis and renal pelvis tissue. As the inflammation continues or recurs, the renal interstitial, renal pelvis, and renal pelvis are damaged, and scars are formed, and the kidneys are atrophied and dysfunctional. Usually, the patient may only have backache and/or low fever, but there is no obvious urinary pain, urinary frequency and urgency symptoms. The main manifestations are nocturia and a small amount of white blood cells and protein in the urine. The patient has long-term or A history of recurrent urinary tract infections, uremia can occur in the advanced stage. basic knowledge The proportion of illness: 2% to 8% Susceptible people: no specific population Mode of infection: non-infectious Complications: urinary tract infection, diabetes, urinary tract obstruction, bacteremia, hypertension, kidney stones

Causes of chronic pyelonephritis

Urinary tract infection (45%)

Chronic pyelonephritis is common in women. Some patients have had acute urinary tract infections during childhood. After treatment, the symptoms disappear, but there are still "asymptomatic bacteriuria", which gradually develops into chronic pyelonephritis in adults.

Immune response (30%)

Some patients with acute pyelonephritis, after infection by the urethral device and stimulate infection, poor urine flow (such as posterior urethral valve, bladder diverticulum, urinary calculi and neurogenic bladder, etc.), vesicoureteral reflux is also caused by repeated urine Road infection, renal scar formation, the main cause of renal dysfunction and urinary tract infection of Gram-negative bacteria can cause systemic and local reactions. In patients with repeated infections, antibodies are increased. Most of these antibodies are IgG and IgA, IgG antibodies. It is possible to form an antigen-antibody complex and to fix complement, thereby causing kidney damage and forming chronic pyelonephritis.

Pathogenesis:

If urinary tract obstruction, malformation and low immunity of the body persist, antibacterial therapy fails to completely control the inflammation or small abscess of the renal pelvis formed by acute pyelonephritis, leaving small scars and causing renal obstruction. , causing repeated attacks and chronic delays.

Some people think that the incidence of chronic pyelonephritis may involve autoimmunity. Some patients find pathogenic bacteria in the urine culture of acute pyelonephritis. In the later chronic process, there is no pathogenic bacteria in the urine culture, and the disease is gradually Entering chronic pyelonephritis, it is speculated that after the kidney infection, the body produces antibodies against Escherichia coli, and the kidney tissue has common antigenicity with these bacteria. After the pathogen disappears, the antibody continues to immunoreact with the kidney tissue antigen. Thus causing kidney damage, a tubular antigen (Tamm-Horsfall protein, called THP) has been found, which has common antigenicity with Escherichia coli, and antibodies against Escherichia coli can simultaneously resist THP of renal tubular epithelial cells. This may be related to the occurrence of chronic inflammation of the renal interstitium.

Modern studies have found that in any chronic kidney disease, once the inflammatory cell infiltration of the renal interstitial occurs, it is possible to cause renal tissue damage through the release of cytokines. The occurrence and development of chronic pyelonephritis may also be related to this.

The presence of L-type bacteria makes the treatment of pyelonephritis more difficult. These bacteria were first discovered by Lister, so the L-type bacteria were named because of the pathogenic bacteria in the treatment of antibacterial drugs or antibodies, complements, and lysozyme. The rupture of the cell membrane, only the original pulp, hidden in the hyperosmolar area of the renal medulla continues to survive, the general antibacterial drugs can not completely kill it, until its living environment improves, L-type bacteria return to the original shape, continue to grow and reproduce, Re-ignition of pyelonephritis, causing the disease to be refractory, according to the investigation of urine culture-negative chronic pyelonephritis, about 20% can find L-type bacteria.

Chronic pyelonephritis prevention

The path of pathogen invasion of pyelonephritis is mainly ascending infection, and the main measures for prevention are as follows:

1. Insist on drinking more water every day, urinating frequently to flush the bladder and urethra, and avoid bacteria in the urinary tract. This is the easiest and most effective measure.

2. Pay attention to the cleansing of the genitals to reduce the bacterial flora in the urethra. If necessary, apply neomycin or furanodine cream to the mucosa or perineal skin of the urethra to reduce the on-site re-infection.

3. Try to avoid using urinary tract equipment and strictly aseptically operate if necessary.

4. Repeated episodes of pyelonephritis should be given a dose of antibacterial drug every night. You can choose one of the drugs such as sulfamethoxazole, furazolidin, amoxicillin or cefradine. If there is no adverse reaction, Can be used for more than 1 year, such as the incidence and sexual intercourse, after sexual life should be urinary, and take a dose of antibiotics, can also reduce the recurrence of pyelonephritis.

Chronic pyelonephritis complications Complications urinary tract infection diabetes urinary tract obstruction bacteremia hypertensive kidney stones

In chronic bacterial pyelonephritis, most kidney scars and kidney damage occur in early childhood. Therefore, most serious complications of urinary tract infection are related to pyelonephritis in children. Although pyelonephritis recurrent, kidney and urinary system develop normally. In adult patients, renal scarring or loss of function is rare, but patients with adult kidney infections complicated with diabetes, urinary calculi, and urinary tract obstruction are at risk for progressive kidney damage and loss of function.

Chronic pyelonephritis patients are prone to bacteremia, hypertension and kidney stones, especially stones with infection, some factors that promote early childhood bacterial pyelonephritis to adult chronic renal insufficiency are: 1 treatment is not complete Or persistent infection; 2 renal hypoplasia or malformation; 3 progressive immune damage; 4 hypertensive renal damage; 5 severe ureteral ureteral reflux damage to the kidney; 6 with infected kidney stones, especially infection Caused by urease producing bacteria.

Chronic pyelonephritis symptoms Common symptoms Urine specific gravity decreased urine osmotic pressure decreased urine occult blood uric acid metabolism urinary amylase increased urinary phosphate excretion increased urinary calcium increased low back pain with frequent urination, urine...

More than half of the patients with this disease have a history of "acute pyelonephritis", actually not acute pyelonephritis, but the first symptoms of chronic pyelonephritis, followed by fatigue, intermittent hypothermia, anorexia, backache, low back pain, quarter ribs or abdomen Symptoms such as mild discomfort, accompanied by frequent urinary tract irritation such as frequent urination, urgency, and dysuria. Acute manifestations also occur frequently. The typical chronic lesions are more insidious.

The clinical symptoms and signs of chronic pyelonephritis can be divided into two categories: one is directly related to the performance of the infection, and the other is related to the extent and location of the kidney damage, the performance directly related to the infection is often not obvious, than the infection And the symptoms of inflammation are more obvious due to long-term tubulointerstitial damage, resulting in renal dysfunction, such as hypertension, loss of Na function (expressed as salt-losing nephropathy), urinary concentrating function, high potassium The tendency of blood and acidosis, although the above manifestations exist in varying degrees in all kidney diseases, in chronic pyelonephritis, the degree of physiological dysfunction is not parallel with the degree of renal failure (high serum creatinine), in other types In kidney disease, when the serum creatinine level is 2 to 3 mg/dl, the physiological dysfunction is small; in patients with chronic pyelonephritis, when the serum creatinine is at the same level, polyuria, nocturia, hyperkalemia have occurred. And performance such as acidosis.

Clinically, such patients are particularly prone to dehydration due to impaired urinary concentration and dilution. Older patients are especially common. When such patients experience vomiting, diarrhea or reduced eating, they are often prone to hypovolemia, shock, and sharp decline in renal function. (Combined with prerenal acute renal failure).

Chronic pyelonephritis causes renal hypertension. It is generally considered to be associated with hyperrenalemia and some vasopressin release and vascular sclerosis and stenosis. A small number of patients can improve their hypertension after removing one side of the diseased kidney. In the advanced stage of the disease, the patient may have glomerular dysfunction, azotemia to uremia, and on the basis of tubulointerstitial damage, focal segmental glomerular sclerosis may occur, manifesting as massive proteinuria or nephropathy. Syndrome, these patients have poor prognosis and can progress to end-stage renal disease.

Chronic pyelonephritis has complex clinical manifestations and is prone to recurrent episodes. The main reason is the presence of predisposing factors and the deformation of the renal pelvis and renal papilla due to scar formation, which is conducive to the latent pathogens.

In addition, due to the long-term application of antibiotics, the bacteria are resistant or enter the cells. Under the action of humoral immunity or antibiotics, the bacterial cell membrane cannot form, and in the medulla hyperosmotic environment, the original pulpy form exists. Bacteria still have vitality. Once they encounter a favorable environment, they re-grow the membrane and multiply the disease. This is the pure-type strain (L-form). Therefore, chronic pyelonephritis is considered to be a disease that is difficult to cure and gradually progress.

Examination of chronic pyelonephritis

Laboratory inspection

1. Urine routine: may have intermittent pyuria or hematuria, the same as acute pyelonephritis in acute attacks.

2. Urine cell count: In recent years, the application of 1h urinary cell counting method, the criteria for judging: white blood cells > 300,000 / h is positive, < 200,000 / h is negative, 200,000 ~ 300,000 / h need to be combined with clinical judgment.

3. Urinary bacteriological examination: true bacterial urinary tract can occur intermittently. In acute attack, it is the same as acute pyelonephritis, and urine culture is mostly positive.

4. Blood routine: red blood cell count and hemoglobin can be slightly reduced, and the white blood cell count and neutrophil ratio can be increased in acute attacks.

5. Renal function test: There may be persistent renal dysfunction: 1 renal dysfunction, such as increased nocturia, morning urine osmotic pressure; 2 acidification decreased, such as morning urine pH increased, urine HCO3- increased, urine NH4 decreased Etc; 3 glomerular filtration function decreased, such as decreased endogenous creatinine clearance, blood urea nitrogen, creatinine and so on.

Film degree exam

1. X-ray examination: KUB plain film can show that one or both kidneys are smaller than normal, IVU can see two kidneys of different sizes, uneven shape, renal pelvis, renal pelvis deformable, dilated, stagnant water, renal parenchyma Thin, with a focal, rough cortical scar, accompanied by blunt or bulging deformation of the adjacent renal pelvis, sometimes poor development, ureteral dilatation, bladder urinary tract contrast, some patients have vesicoureteral reflux, in addition It can be found that there are urinary flow disorders, urinary tract obstruction such as stones, tumors or congenital malformations and other susceptibility factors.

2. Radionuclide scanning: The patient's renal dysfunction can be determined, showing that the kidney is small, and the dynamic scan can also detect vesicoureteral reflux.

Cystoscopy may reveal inflammatory changes in the ureteral orifice of the affected side, ureteral intubation is blocked, and intravenous injection of rouge confirms impaired renal function.

3. Renal biopsy: light microscopy can show tubular atrophy and scar formation, interstitial lymphocytes, mononuclear cells infiltration, neutrophil infiltration in acute attacks, glomeruli can be normal or mild around the ball Fibrosis, if there is long-term high blood pressure, it can be seen that the glomerular capillary wall is hardened and the collagen in the glomerular capsule is deposited.

Diagnosis and diagnosis of chronic pyelonephritis

diagnosis

At present, most scholars believe that the diagnostic criteria should be strict. Imaging examination revealed renal cortical scar and renal pelvis and renal pelvis deformation, abnormal renal function tests, and evidence of urinary tract infection in the medical history or urine bacteriological examination, such as Without the above changes, the history of urinary tract infection can not be diagnosed as a disease. For patients with chronic pyelonephritis, a thorough examination should be carried out to clarify: 1 pathogenic bacteria; 2 unilateral or bilateral infection; 3 primary lesions ; 4 extent of renal parenchymal damage and degree of renal impairment; 5 with or without urinary tract obstruction.

Differential diagnosis

1. Lower urinary tract infection: If urinary protein is displayed, Tamm-Horsfall mucin, -microglobulin, etc., urinary sediment antibody-encapsulated bacteria positive, white blood cell cast and kidney morphology and dysfunction, all contribute to chronic pyelonephritis Diagnosis, if necessary, can be used for bladder irrigation and sterilization. If the bladder is sterilized for 10 minutes, the number of bladder urinary bacteria is small, suggesting cystitis; if the number of bacteria before and after sterilization is similar, it is pyelonephritis.

Clinically, there is a disease called urethral syndrome (also known as symptomatic sterile urine), which occurs in middle-aged women. The patient has frequent urination, urgency, dysuria, and dysuria. The white blood cells in the urine can also be used. Increased, often misdiagnosed as atypical chronic pyelonephritis and long-term blind application of antibacterial drugs, and even cause adverse consequences, must be identified, urethral syndrome multiple mid-stage urine quantitative culture, no true bacterial urine and exclude false negatives can be identified.

2. Kidney tuberculosis: Patients with renal tuberculosis have a history of extrarenal tuberculosis or lesions. The gross hematuria is common. The symptoms of bladder irritation are significant and lasting. There are often symptoms of tuberculosis poisoning. The smear of urine sediment can find acid-fast bacilli and common methods of urine bacteria. The culture is negative, the urinary tuberculosis culture is positive, etc., and if necessary, intravenous pyelography, if the renal parenchyma-like destructive defect is found, it is helpful for diagnosing renal tuberculosis.

3. Chronic glomerulonephritis: in the absence of significant edema, proteinuria, hypertension, its clinical manifestations are similar to atypical chronic pyelonephritis with systemic infection symptoms and urinary tract irritation symptoms, especially when patients with chronic glomerulonephritis When complicated with urinary tract infection, or both of them have chronic renal dysfunction in the late stage, the identification is more difficult. It is generally considered that there is systemic edema in the medical history; in the urine, there are proteins with more than medium molecules, and the protein and tube type are more, white blood cells. Less; first glomerular filtration function is impaired, and heavier than renal tubular function; and renal X-ray examination shows that the two kidneys are symmetrical, the shape is smooth, and there is no renal pelvis and renal pelvis deformation to support chronic glomerulonephritis. In the course of the disease, the symptoms of kidney and urinary tract irritation are obvious; the urine routine is mainly white blood cells, and there is a small amount of proteinuria mainly composed of small molecules; the middle urinary bacteria culture is positive; the tubular dysfunction is earlier than and heavier than the glomerular function. Damage, as well as kidney X-ray examination of the two kidneys of different sizes, uneven shape, renal pelvis and renal pelvis deformation, etc., support chronic pyelonephritis.

4. Non-infectious chronic interstitial nephritis: insidious onset, diverse clinical manifestations, urine and renal function tests and chronic pyelonephritis are similar, confusing, but non-infectious chronic interstitial nephritis has the following characteristics: 1 has a longer period Urinary tract obstruction or long-term exposure to nephrotoxic substance history; 2 renal tubular dysfunction; 3 azotemia, but no history of edema and hypertension; 4 mild proteinuria, further examination for renal tubular proteinuria; 5 vein Renal pyelography can be seen in bilateral renal shadows, irregular shape (scar formation), renal pelvis deformation (expansion and dullness); 6 kidney map, radionuclide scanning or B-ultrasound imaging, can show bilateral renal lesions Equal, and the difference between chronic pyelonephritis is mainly urinary tract irritation, intermittent true bacterial urine; intravenous pyelography has signs of chronic pyelonephritis, that is, focal, rough cortical scar, accompanied by adjacent renal pelvis It becomes blunt or drum-like deformation, and the renal pelvis can sometimes be deformed. It has enlargement and water accumulation. If it is still difficult to identify, it can be considered as a renal biopsy to help diagnose or exclude other chronic kidney diseases.

5. Hematuria type of chronic pyelonephritis: Hypertensive and occult patients should be differentiated from other diseases causing hematuria, hypertension, asymptomatic bacteriuria, etc., by detailed medical history, observing kidney and urinary tract symptoms, Signs and repeated routine urine, cell and bacteriological examination, if necessary, for renal X-ray examination, etc., can be identified.

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