Interstitial (tubulointerstitial) nephritis is a disease characterized by inflammation of the interstitial tissue and renal tubules. This pathology can develop as a result of previous infections, the use of certain medications, metabolic disorders, intoxication and the formation of malignant tumours. Interstitial nephritis can occur in acute and chronic forms.
Acute interstitial nephritis is expressed by inflammatory changes in the interstitial tissue. In severe cases, this provokes the development of acute renal failure, but the disease has a predominantly favorable prognosis.
Chronic interstitial nephritis is characterized by fibrosis of the interstitial tissue, tubular atrophy, and damage to the renal glomeruli. The chronic form of this disease leads to nephrosclerosis and causes chronic renal failure.
Interstitial Nephritis Causes
The causes of interstitial nephritis include a number of factors, including:
- The use of drugs: antibiotics, fluoroquinolones, nonsteroidal antiseptic drugs, sulfonamides, diuretics (penicillin, ampicillin, cephalothin, gentamicin, ibuprofen, captopril, naproxen);
- Infectious diseases caused by bacteria (streptococcus, diphtheria) and viruses (cytomegalovirus, hemorrhagic fever);
- Diseases of the immune system (systemic lupus erythematosus);
- Multiple myeloma;
- Poisoning with heavy metals (lead, mercury, cadmium);
- Metabolic disorders, etc…
When the cause of interstitial nephritis remains unclear, it is called idiopathic.
Interstitial Nephritis Symptoms
The clinical symptoms of interstitial nephritis depend on the degree of intoxication of the body and the intensity of the development of the disease.
Symptoms of an acute form of interstitial nephritis usually appear 2-3 days after the onset of various infectious diseases (tonsillitis, tonsillitis, flu, sinusitis) and taking antibiotics, diuretics and medicinal serums. Patients present with weakness, lethargy, loss of appetite, nausea, or vomiting. Often these symptoms are accompanied by an increase in body temperature, muscle pain (myalgia), an allergic skin rash, and a slight increase in blood pressure. Acute interstitial nephritis is not characterized by urinary disturbances and edema… Only in very severe cases of the disease in patients decreases the amount of urine (oliguria), up to the complete cessation of the flow of urine into the bladder (anuria). From the first days of the disease, patients develop renal failure of varying severity, but with adequate treatment, these phenomena are completely reversible and disappear after a couple of weeks. Concentration function of the kidneys usually returns to normal after 2–3 months.
According to the peculiarities of the clinical picture, acute interstitial nephritis is divided into four forms:
- Expanded form (all clinical symptoms of the disease are expressed);
- Severe form (manifestations of acute renal failure, prolonged anuria; the patient is shown acute hemodialysis);
- “Abortive” form (absence of anuria, favorable course, rapid restoration of kidney function);
- “Focal” form (mild clinical symptoms of interstitial nephritis, acute polyuria (increased urine production), favorable course, rapid recovery).
The chronic form of interstitial nephritis has a more unfavorable course. For the later stages of the disease, changes in the functioning and structure of the renal glomeruli, the development of glomerulosclerosis and chronic renal failure are characteristic. Symptoms include wave fever, allergic itchy rash, low back pain, anuria or polyuria, dry mouth and thirst, increased blood pressure, anemia. The development of glomerulosclerosis leads to edema and proteinuria. The prognosis for the treatment of chronic interstitial nephritis depends on the rate of development of renal failure and renal glomerular damage.
Interstitial Nephritis Treatment
Early diagnosis and withdrawal of medications that provoke the development of the disease are extremely important for the treatment of interstitial nephritis. If possible, the number of drugs used is reduced, nephrotoxic agents are replaced with non-toxic ones. With polyuria, the volume of fluid consumed is increased, and with oliguria, it is reduced. Patients with oligoanuria are prescribed hemodialysis, which restores kidney function. If necessary, a short course of glucocorticoid therapy is carried out, cytostatics are used.
Treatment prognosis for acute interstitial nephritis is good; recovery occurs after a few weeks or months. With a slow recovery of kidney function, prolonged anuria and damage to the interstitium, acute interstitial nephritis becomes chronic.
The chronic form of interstitial nephritis requires restoration of water and electrolyte metabolism in the patient; measures are taken to eliminate factors affecting the interstitium, the functions of the urinary tract are normalized. Also, therapy is aimed at treating chronic renal failure.