Diagnosis of acute pyelonephritis

The diagnosis of acute pyelonephritis is made in the cases of the first emerging infectious and inflammatory process in the tubal-pelvic system and tubulo-interstitial tissue of the kidneys, which takes 4-8 weeks, followed by a favorable dynamics of clinical and laboratory symptoms and recovery no later than 3-6 months from the beginning disease.

Chronic pyelonephritis is diagnosed if symptoms of the disease persist for more than 6 months from its onset or if there are 2-3 relapses during this period.

In the active stage, the clinical signs and indices of activity of the process are expressed, the function of the kidneys can be preserved or broken. If the renal function is impaired, the type and nature of the disorder is indicated.

Under the full clinical-laboratory remission is understood the following changes:

1. the disappearance of clinical symptoms;
2. normalization of urine sediment during routine research and according to quantitative research methods;
3. return to age norms of blood indicators;
4. disappearance of pathological bacteriuria and sowing of pathogenic microbes from urine;
5. recovery of kidney function.

The period of partial remission is the absence of clinical symptoms or their weak expression, a significant decrease in shifts in the urine sediment, the absence of pronounced functional renal impairment, and changes in blood.

You can talk about recovery if you have complete clinical and laboratory remission for at least three years. The patient should be examined in a comprehensive manner in the conditions of a specialized nephrological hospital before the diagnosis is withdrawn.

In outpatients in the urine, excretion of E. Coli prevails, and when infected in hospital conditions the etiological importance of Klebsiella, Pseudomonas aeruginosa, enterococcus increases.

Laboratory diagnostics of acute pyelonephritis.

1. The urine sediment: proteinuria is less than 0.3-0.5 g / l; leukocyturia of neutrophilic nature.
2. Bacteriuria: a norm of 10 ⁵ (100 000) microbial bodies in 1 ml of urine, taken by the usual method. TTX-test, a test with tetraphenyltetrazolium chloride.
3. Quantitative methods of urine testing: the norm of the Kakovsky-Addis test (for a day of leukocytes - 2 million, erythrocytes - 1 million, cylinders - 10,000). Bacteriological method for determining bacteriuria using phase-contrast microscopy (Stanford-Webb method). The norm is up to 3 white blood cells per 1 μl.
4. At girls simultaneously the research of urine from an average portion and a smear from a separated vagina.
5. Sowing urine on the flora - again, at least 3 times.
6. Determination of titres of antibacterial antibodies with pyelonephritis (over 1: 160).
7. Urinary excretion of bacteria coated with antibodies in immunofluorescence study.
8. Dynamics of antibodies to lipid A.
9. DNA probe diagnostics are comparable to polymerase chain reaction (PCR).
10. Determination of urinary P-lysine activity.
11. Definition of IL-1 and IL-6 in urine.
12. Analysis of daily urine for salt content (norm: oxalate - 1 mg / kg / day, urate - 0,08-0,1 mmol / kg / day, or 0,6-6,0 mmol / day, phosphates -19-32 mmol / day).

Research of kidney function. With the functional methods of studying the kidneys with pyelonephritis, the following disorders can be detected: in the Zimnitsky trial, a decrease in the concentration capacity of the kidneys-hyposthenuria or isostenuria. Violation of the function of urine concentration testifies to the damage to the interstitial tissue of the kidney; impaired renal function to maintain CBS due to a decrease in the ability to form ammonia and a lower excretion of hydrogen ions by the cells of the renal tubules; violation of acid-ammoniogenesis reflects the function of the distal tubule of the kidneys; determination of the content of beta _2- microglobulin in the urine. A significant increase is noted with a primary lesion of the proximal tubules of the kidneys. The norm of beta _2- microglobulin in the urine is from 135 to 174 μg / l. In patients with pyelonephritis, there was an increase in its level of 3-5 or more times.

Ultrasound changes in pyelonephritis include: increased kidney lesions in the volume, dilated calyx and pelvis, and sometimes it is possible to contour compressed papillae. When involved in the process of the bladder, signs of thickening of the mucous membrane are revealed, the shape of the bladder changes. There may be dilatation of the distal ureter. In this case it is necessary to perform an instrumental examination to exclude vesicoureteral reflux. Cystography and mycation cystography are performed.

Radioisotope renography reveals a one-sided lesion, a decrease in the secretory activity of the renal parenchyma, a slowing of the excretory function. In this case, the presence of fluctuations in the region of the excretory segment of the curve, the stepped nature of excretion of the pharmaceutical is an indirect sign of vesico-renal reflux. As the progression occurs, the vascular segment of the renogram decreases, the secretory phase slows down with a decrease in the degree of ascent of the curve, the excretory segment sharply stretches in time, flattened.

Radiocontrast study allows revealing anomalies of the kidney and urinary system, sclerosing the kidney tissue. On the roentgenogram with acute non-obstructive pyelonephritis, the contouring of the papillae, the spasm of the calyxes, moderate deformation and expansion, their unequal size, and the fuzziness of the contours are eliminated. Indirect radiographic signs of vesicoureteral reflux is a partial one- or two-sided enlargement of the distal ureter, filling the ureter with a contrast medium all the way, often combined with a total expansion of the ureter, renal pelvis and calyxes.

Computer tomography reveals up to 85% of minimal structural damage to the renal parenchyma.

Endoscopic methods. Transurethral ureteropyeloscopy allows a more subtle diagnosis of the developmental defects of the upper urinary tract, the extent of segmental dysplasia of the ureter, determine the valve or membrane of the ureter. Only this method allows to diagnose small vascular tumors of the pelvis and calyces (hemangiomas, papillomas), which are often the cause of many years of microhematuria of unclear etiology.

Progress has been made in the field of prenatal diagnosis of kidney pathology. From the 15th week of the intrauterine period, ultrasound screening can diagnose congenital malformations of the kidneys (single, bilateral anomalies, ureteral obstructions, polycystic kidney disease, severe renal dysplasia.

Classification of pyelonephritis in children

The form of pyelonephritis	Activity	Kidney function
1. Acute pyelonephritis	1. Active stage 2. The period of reverse development 3. Complete clinical and laboratory remission	Preservation of kidney function. Impaired renal function
2. Chronic pyelonephritis - primary non-obstructive - Secondary obstructive A) recurrent B) latent flow	1. Active stage 2. Partial clinico- laboratory remission 3. Complete clinical and laboratory remission	Preservation of kidney function Impaired renal function Chronic Renal Failure

[1], [2], [3], [4], [5], [6], [7], [8], [9], [10]