Interstitial nephritis is an inflammation of the kidneys that can be acute or chronic. In addition to viral and bacterial causes, autoimmune diseases and drug noxae are possible triggers. The treatment consists in eliminating the causative noxa and serves to preserve kidney function.
What is interstitial nephritis?
In at least 15 percent of all cases, patients suffer from fever, exanthema of the skin or arthralgia. Some patients complain of flank pain. See AbbreviationFinder for abbreviations related to Interstitial Nephritis.
The kidneys are some of the most important detoxification organs in the human body. They filter the blood free of harmful substances and remove these substances from the body in the form of urine. Damage to the kidney tissue can lead to functional impairments of the filter system. Lesions in the kidney tissue have different causes.
For example, inflammation leaves scars in the tissue, which can cause permanent impairment of kidney function, especially in the renal tubublus system. Like pyelonephritis or pelvic inflammatory disease, interstitial nephritis or tubulo-interstitial nephritis is an inflammatory disease. While inflammation of the renal pelvis is usually associated with bacterial infections, tubulointerstitial nephritis is not necessarily a bacterial infection.
The disease shows low incidence, so it is rare. Inflammation was first described in 1878. Jean-Martin Charcot is considered to be the first to describe it. He already documented at the time that the late-stage disease expands the tubular epithelium and can lead to death from kidney failure. In addition to an acute form of the disease, he pointed to a chronic form that extends over a long period of time and allows gradual kidney failure to occur.
The causes of interstitial nephritis differ with the form. The acute form can correspond, for example, to an allergic-hypersensitive reaction to medication, especially to antibiotics such as ampicillin, methicillin, cimetidine, NSAIDs, diuretics or proton pump inhibitors. Plant toxins are also possible triggers.
In addition, the acute variant can be of a viral nature and can thus be traced back to the hantavirus, for example. In addition, acute para-infectious forms can occur as part of bacterial infections with streptococci, legionella or similar pathogens. The cause of the acute autoimmune form are, in turn, autoimmune diseases such as Goodpasture’s syndrome.
Chronic interstitial nephritis occurs as an allergic-toxic event to other drugs than the acute form, especially analgesics. In addition, this form is often associated with substances such as lead and cadmium or has a metabolic origin, for example in the context of hyperuricemia in gout. Hypercalcaemia, hyperoxaluria, hypokalemia and cystinosis can also be causative.
The chronic form of ADPKD is hereditary in nature. It is autoimmunological in nature in SLE, in the context of Sjogren’s syndrome and in sarcoidosis. In addition, there are infectious and obstructive diseases such as chronic bacterial phyelonephritis. Apart from that, the chronic form can adjust itself to physical influences, for example in the form of radiation nephritis.
Symptoms, Ailments & Signs
Tubulo-interstitial nephritis is characterized by a clinically diverse picture. All changes in the renal parenchyma can remain asymptomatic as part of the disease. However, the lesions can also lead to a partial failure of tubular functions or even trigger acute kidney failure.
In the case of acutely manifest tubulointerstitial nephritis, hypersensitivity reactions sometimes occur in addition to the renal symptoms. In at least 15 percent of all cases, patients suffer from fever, exanthema of the skin or arthralgia. Some patients complain of flank pain. In the chronic form, the patient’s condition deteriorates gradually.
The pathology differs depending on the form. In acute interstitial nephritis, the interstitium is edematous. Mononuclear infiltrates from plasma cells, lymphocytes and eosinophilic granulocytes can be detected. Chronic interstitial nephritis also leads to tubular atrophy and glomerulopathy.
The symptoms and pathology of the kidney tissues in detail provide information about the cause of the inflammation. In allergic reactions, for example, skin symptoms are common, while increased eosinophilic granulocytes are found in the tissue.
Diagnosis & course of disease
Laboratory tests for suspected interstitial nephritis include determination of urea and creatinine. Urine sediment and 24-hour urine collection are indicated. Tubular dysfunction can produce hematuria or proteinuria, hyperphosphaturia, and aminoaciduria or glucosuria. Elevated urine pH or salt loss also indicates the disease.
The suspicion of the acute form can be substantiated with the detection of eosinophilia or an increase in IgE. In the acute form, sonography again shows a hyperechoic and widened parenchyma. The prognosis of patients depends on the form of the disease and the time of diagnosis. The acute form has a relatively favorable prognosis.
In the worst case, this disease can even lead to the death of the patient. Death can occur if the kidneys fail and proper treatment is not instituted. Likewise, the affected person is then dependent on dialysis or an organ transplant in order to continue to survive. The quality of life is significantly reduced by this disease.
It is not uncommon for those affected to suffer from a strong fever and also to complaints on the skin. Flank pain also occurs, which leads to restricted mobility. The symptoms make everyday life much more difficult for the patient. The constant pain and discomfort often leads to mental illnesses or even depression.
Treatment is with the help of drugs. There are no particular complications. However, renal insufficiency must be avoided at all costs so that it does not lead to a life-threatening condition for the patient. The life expectancy of the person affected may be reduced by the disease. If necessary, psychological treatment of the patient can also take place in order to avoid depression or other complaints.
When should you go to the doctor?
People who notice typical warning signs such as fever or skin rashes should see a doctor as soon as possible. Interstitial nephritis must be diagnosed and treated with medication to rule out subsequent damage to health. In addition, the disease significantly reduces the quality of life. That is why medical advice is required at the first sign of kidney inflammation. Those who regularly take antibiotics or who have recently had a bacterial infection are particularly susceptible to developing interstitial nephritis.
People with gout, hypercalcemia or sarcoidosis are also among the risk groups and should definitely have the symptoms mentioned examined. The appropriate doctor is the general practitioner or a nephrologist. In the case of existing underlying diseases, the doctor responsible is optimally informed. Children should be taken to the pediatrician if they have kidney problems. If psychological problems have already developed, therapeutic help is also recommended. The patient should seek comprehensive treatment for physical and psychological symptoms early on in order to avoid negative health consequences.
Treatment & Therapy
Treatment of tubulointerstitial nephritis focuses on eliminating the primary cause or treating the underlying disease. In the case of drug-related causes, the drugs are discontinued in order to eliminate the causative noxa. If acute renal failure occurs, hemodialysis takes place. Drug therapy is indicated primarily for autoimmune diseases.
Prednisone is often given for immunosuppression. Some progress has also been observed in connection with therapies involving intravenous or oral administration of corticosteroids . In addition, mycophenolate mofetil has recently been used for treatment. If the triggering noxa can be eliminated, more than half of all cases heal without chronic kidney failure developing.
In the chronic form, the glomeruli of the kidneys are often affected. For this reason, additional supportive measures are often used during treatment. This supportive therapy serves to prevent chronic renal insufficiency and should prevent further deterioration of the function. Evidence-based treatments are not available.
Outlook & Forecast
The prognosis of interstitial nephritis depends on the disease trigger present. Without treatment or therapy, an increase in the symptoms that have occurred is to be expected. The general well-being decreases continuously and the symptoms increase. In severe cases, kidney failure can occur. This poses a potential threat to the life of the person concerned.
Dialysis is necessary to ensure survival. In the long term, the patient needs a donor kidney. Organ transplantation is the only way to improve the patient’s quality of life and life expectancy. The surgical procedure is associated with various complications and side effects. The healing path is lengthy and limitations in coping with everyday life are to be expected.
If medical treatment is used at an early stage, drug treatment is used after the cause has been clarified. The aim of this is to kill pathogens and germs. They are then transported out of the body by the organism. At the same time, there is an improvement in health. Existing symptoms are alleviated and, ideally, recovery occurs.
With interstitial nephritis there is a risk that I will permanently stop pain and irregularities. In addition, it can lead to psychological complications due to the strong mental stress. These worsen the overall prognosis of the patient.
Since interstitial nephritis can have a number of causes, all-encompassing prophylaxis is not possible.
Follow-up care for interstitial nephritis depends on the cause of the condition. Since there can be various triggers, there are no clear recommendations for follow-up treatment and prophylaxis. However, patients can take certain measures as instructed by the doctor to promote therapy.
If symptoms are caused by an unsuitable drug, the patient should think about an alternative together with the doctor. After stopping the drug, there may be interactions and side effects. Based on the feedback from the doctor, an improved medication can be put together. If the disease is based on kidney failure, the patient must take it easy and stay in bed.
Dieting also helps reduce complications and relieve pain. Kidney failure can be counteracted by a healthy lifestyle with sufficient but moderate exercise. Avoiding stress is also important, not only in the recovery phase, but also as a preventive measure. In addition, those affected should have regular medical examinations in order to be able to act quickly in the event of problems.
In the case of a chronic disease, a permanent change in diet is recommended. If necessary, a psychotherapeutic consultation is useful. This helps those affected to better understand themselves and improve their quality of life. Patients can also find a self-help group through their doctor or therapist.
You can do that yourself
Interstitial nephritis first requires a diagnosis by the doctor. The patient can take some measures to support the medical treatment.
If the symptoms are caused by a poorly adjusted medication, this must first be discontinued. The person concerned should then make a note of any side effects and interactions of the prescribed drug and inform the doctor of this so that the optimal medication can be reached quickly. If kidney failure is the cause, rest and bed rest are the priority. In addition, the patient should change their diet to avoid pain, dysfunction and other complications. In the case of acute kidney failure, the most important self-help measures are a healthy lifestyle with moderate exercise and a balanced dietand to avoid stress. Chronic interstitial nephritis requires close monitoring by the responsible physician. In addition, the affected person should adapt their lifestyle to the respective symptoms.
Since a chronic disease represents a significant cut in quality of life and well-being, therapeutic advice is often useful. The doctor can also establish contact with other sufferers or a self-help group. In the long term, the symptoms of kidney inflammation can be alleviated by dietary measures, rest and drug treatment.