What is Chronic Pyelonephritis
Chronic pyelonephritis is a severe form of inflammation affecting the kidney and renal pelvis, characterized by inflammatory infiltration and interstitial fibrosis (scars left by recurrent infections). The pathological process leads to the progressive atrophy of the affected organ and to degenerative anatomical alterations that can be recognized through radiographic investigations. In advanced cases, secondary glomerular sclerosis may appear, which results in reduced functional capacity of the kidneys (chronic renal failure).
Unlike the acute form, which manifests itself as a single and sudden episode following a "€ ™ bacterial infection, chronic pyelonephritis develops over a prolonged time, due to repeated damage to the kidney tissue caused by recurrent infectious processes or persistent.
Some factors predispose to the disease, such as the presence of a structural or functional abnormality of the urinary tract that makes the individual susceptible to kidney infections.
Chronic pyelonephritis often begins insidiously (gradually and with atypical symptoms) and is diagnosed when the kidney lesions are now in an advanced stage. In many cases, the predisposing conditions highlighted for acute pyelonephritis are determining factors at the basis of the onset of the disease. In adults, episodes of recurrent or persistent infection generally play a fundamental role in the onset of the chronic form. , which can be determined by two further main causes:
- reflux nephropathy - associated with vesicoureteral and / or intra-renal reflux of infected urine;
- chronic obstructive pyelonephritis - associated with anatomical-functional problems, such as obstructions of the renal tract, which predispose to infections.
Chronic pyelonephritis can develop even in the absence of previous urinary tract infections: Individuals with an abnormality in the ureter-to-bladder junction (vesicoureteral junction) may develop the disease in childhood. This congenital condition allows urine to flow retrograde from the bladder into the ureter to the kidney. Severe reflux can lead to kidney scar formation on its own, even in the absence of other known factors. Interstitial fibrosis of the kidneys associated with vesicoureteral reflux is similar to that seen with repeated infection combined with structural abnormalities.
Epidemiology
Chronic pyelonephritis affects women more frequently than men. Prevalence is 4 in every 1,000 asymptomatic adults. However, the prevalence rises to 40-50% of infants and children with urinary tract infections (reflux nephropathy).
Risk factors
- Anatomical-functional alterations:
- Congenital changes, such as some structural defects of the urinary tract
- Acquired: tumors, strictures, kidney stones.
- Vesicoureteral reflux.
- Any other factors that predispose to recurrent urinary tract infections, such as: diabetes, neurogenic bladder (particular form of urinary incontinence, in which the loss of urination control is due to nerve damage) ...
Symptoms
Often, the disease goes on for several years without giving rise to any obvious symptoms, only to be diagnosed when signs of renal failure appear. Other times, the first signs are nonspecific symptoms such as fatigue, loss of appetite, nausea, vomiting and headache, while, in other cases, recurrent episodes of urinary tract infections occur.
Chronic pyelonephritis causes persistent abdominal and flank pain, clinical signs of infection (fever, unintentional weight loss, malaise), lower urinary tract symptoms, and blood in the urine. Chronic pyelonephritis can occur with fever and hypertension. In addition, certain inflammation-related proteins can accumulate in organs and cause a condition of AA amyloidosis (inflammatory, reactive and secondary amyloidosis from chronic inflammation).
Diagnosis
The clinical diagnosis of chronic pyelonephritis is not easy; in fact, if the diagnostic tests are performed in a phase of inactivity of the disease, it is possible to find normal findings. The reported symptoms may vary according to the presence or absence of an infectious process: individuals without infection may be asymptomatic until the most advanced stages of chronic pyelonephritis are reached. Symptoms can be nonspecific: high blood pressure (hypertension) and signs of kidney failure such as generalized malaise, feeling tired (asthenia), memory loss, easy fatigue, nausea and loss of sexual desire (libido). a kidney infection, the individual may complain of symptoms similar to those of acute pyelonephritis, with the rapid development of clinical signs over the course of a few hours or days.
Patients may report high fever (38.3 ° C to 40 ° C or higher) and chills, flank pain, particularly in the lower back on the right side, increased frequency of urination, pain and a burning sensation at the time of urination (dysuria), nausea and vomiting, loss of appetite (anorexia) and general fatigue.
