Chronic pyelonephritis

Bacterial chronic pyelonephritis is a term used to describe the effects on the kidney of a long-term infection. And it can be both an active process with a persistent infection, and the consequences of an earlier transferred kidney infection. These two conditions: active or inactive (healed) chronic pyelonephritis - differ in the presence or absence of morphological signs of infection, leukocyturia and bacteriuria. This distinction is of great importance, since the treatment is not shown in the inactive process.

[1], [2], [3], [4], [5],

Causes of the chronic pyelonephritis

Bacterial pyelonephritis is almost invariably found in patients with a complicated urinary tract infection or with diabetes mellitus. The process is highly variable, depends on the state of the host organism and the presence of structural or functional changes in the urinary tract. The process can persist for many years, if the damage is not corrected. Long-term infection leads to weakening of the body and anemia. The probability of complications is high: amyloidosis of the kidneys, arterial hypertension and terminal renal failure.

Not many diseases cause as much debate and controversy as chronic pyelonephritis. The word "chronic" evokes a vision of a persistent, smoldering process, which unfailingly leads to the destruction of the kidney, if its flow does not interrupt, i.e. In the outcome of the disease should develop nephrosclerosis and pimple of the kidney. In fact, most patients with urinary tract infection, even with frequent recurrent attacks, rarely have renal failure in later stages. After relapsing infections in the absence of organic or functional changes in the urinary tract, both after the primary acute form of the disease (at least in adults), nephrosclerosis and chronic kidney failure does not happen. They are more likely to occur on the background of diabetes, urolithiasis, analgesic nephropathy, or obstruction of the urinary tract. That is why it is extremely important to accurately determine the terminology and risk factors.

Another source of confusion is the tendency to interpret focal kidney scars and deformed calyxes visible on excretory urograms, rather as "chronic pyelonephritis" than as the old healed pyelonephritic scars or the result of reflux-nephropathy. It is known that scars acquired after an acute form of the disease and vesicoureteral reflux in childhood are the main source of findings in adults. The key role of vesicoureteral reflux in the development of renal scars is based on the work of a number of researchers.

Chronic pyelonephritis is the result of a combined action of the infection and violation of urodynamics due to organic or functional changes in the urinary tract.

In children, nephrosclerosis often develops against a background of vesicoureteral reflux (reflux-nephropathy). An immature developing kidney is damaged by a bacterial infection more easily than a formed organ. In general, the younger the child, the higher the risk of irreversible damage to the renal parenchyma. In children older than 4 years with vesicoureteral reflux, new sclerosis sites are rarely formed, although the old ones can increase. In addition to the child's age, the severity of reflux-nephropathy directly depends on the severity of vesicoureteral reflux.

[6], [7]

Symptoms of the chronic pyelonephritis

Symptoms of chronic pyelonephritis most often manifested nonspecific signs of infection, including fever, anemia, azotemia. Perhaps the asymptomatic course of chronic pyelonephritis, or there may be recurrent episodes of an acute form of the disease or manifestation.

[8], [9], [10], [11], [12]

Complications and consequences

Uncontrolled infection in the kidneys can spread into surrounding tissues and form a perinephric abscess. The length of the infectious process is difficult to determine without radiological studies. Perinephric abscess should be suspected in the presence of constant pain in the side, fever, leukocytosis, despite the ongoing antibiotic chemotherapy. Usually, surgical drainage is required. The patient may develop urosepsis, often accompanied by bacteremia and endotoxemia.

[13], [14], [15], [16], [17]

Diagnostics of the chronic pyelonephritis

Laboratory diagnostics of chronic pyelonephritis

The laboratory data are similar to those in the acute form of the disease. Patients with a long-term infection may have normocellular, normochromic anemia with normal iron-binding protein and ferritin.

C-reactive protein usually increases in patients with active infection. In patients with severe bilateral infection, the content of urea and serum creatinine increases. Concentration of the kidneys is markedly reduced, but excessive proteinuria is rare, with the exception of terminal renal failure.

[18], [19], [20], [21], [22], [23]

Instrumental diagnosis of chronic pyelonephritis

Radiological data mainly consists of anatomical changes associated with the structural changes and the consequences of the infectious process. The renal cortex can be wrinkled due to multiple, uneven cortical scars with focal folding of the pelvis. These changes can be confused with changes that arise with vesicoureteral reflux and renal arterial hypertension. With CT, it is possible to identify an abscess that can contain gas (emphysematous chronic pyelonephritis) or have a similarity to a tumor (xanthogranulomatous form of the disease).

Differential diagnosis

Clinical diagnosis of active, bacterial chronic pyelonephritis is based on the history of the disease, clinical, laboratory and radiological data. In patients with recurrent, complicated infection or with diabetes mellitus, in which the symptoms of the disease are associated with bacteriuria and pyuria, it is not difficult to establish a diagnosis. The main problem is to distinguish residual infections of the past infectious process, which are more inactive, from other diseases that have similar radiological data.

The states that can mimic chronic pyelonephritis are presented below:

Clinical:

• kidney stones and ureteral obstruction;
• kidney tumor;
• sub-diaphragmatic and lumbar abscess;
• fever of unknown etiology.

Radiological:

• reflux-nephropathy;
• arterial hypertension of renal genesis;
• stenosis of the renal artery:
• diabetic nephropathy;
• interstitial nephritis;
• analgesic nephritis.

Treatment of the chronic pyelonephritis

Treatment of chronic pyelonephritis is carried out using the use of surgical and antibacterial methods of treatment.

If the process of untreated or chronic pyelonephritis was treated inadequately, the process can persist for many years and is complicated by general weakness, anemia and gradually progresses to renal amyloidosis, arterial hypertension and terminal renal failure.