Interstitial nephritis

The interstitial nephritis is inflammation of the kidneys, which can be acute or chronic. In addition to viral and bacterial causes, autoimmune diseases and medicinal noxae can be triggers. Treatment consists in eliminating the causative agent and preserving kidney function.

What is interstitial nephritis?

The kidneys are sometimes the most important detoxification organs in the human body. They filter the blood from pollutants and remove these substances from the body in the form of urine. Damage to the kidney tissue can impair the function of the filter system. Lesions in kidney tissue have different causes.

Inflammation, for example, leaves scars in the tissue, which can cause permanent impairment of kidney function, especially in the renal tube system. As with pyelonephritis or inflammation of the renal pelvis, it is also with the interstitial nephritis or tubulo-interstitial nephritis an inflammatory disease. While renal pelvic inflammation is usually associated with bacterial infections, tubulo-interstitial nephritis is not necessarily a bacterial inflammation.

The disease has a low incidence, so it is rare. The inflammation was first described in 1878. Jean-Martin Charcot is considered the first to describe it. He already documented at the time that the late-stage disease enlarges the tubular epithelium and can lead to death from kidney failure. In addition to an acute form of the disease, he pointed out a chronic form that extends over a long period of time and causes creeping kidney failure.

causes

The causes of interstitial nephritis differ with shape. The acute form can, for example, correspond to an allergic-hypersensitive reaction to drugs, especially to antibiotics such as ampicillin, methicillin, cimetidine, NSAIDs, diuretics or proton pump inhibitors. Vegetable poisons can also be used as triggers.

In addition, the acute variant can be of a viral nature and thus go back to the hantavirus, for example. In addition, acute parainfectious forms can occur in the context of bacterial infections with streptococci, legionella or similar pathogens. The acute autoimmunological form is caused by autoimmune diseases such as Goodpasture syndrome.

Chronic interstitial nephritis, as an allergic-toxic event, occurs in response to other drugs than the acute form, above all to analgesics. In addition, this form is often associated with substances such as lead and cadmium or has a metabolic cause, for example in the context of hyperuricemia in gout. Hypercalcemia, hyperoxaluria, hypokalaemia and cystinosis are also causative factors.

The chronic form of ADPKD is hereditary in nature. It is autoimmunological in SLE, Sjögren's syndrome and sarcoid. In addition, there are infectious and obstructive diseases such as chronic bacterial phyelonephritis. Apart from that, the chronic form can adapt to physical influences, for example in the form of radiation nephritis.

Symptoms, ailments & signs

Tubulo-interstitial nephritis is characterized by a diverse clinical picture. All changes in the renal parenchyma can remain asymptomatic as part of the disease. However, the lesions can just as easily lead to a partial failure of the tubule functions or even trigger acute kidney failure.

In acute tubulo-interstitial nephritis, the renal symptoms are sometimes accompanied by hypersensitivity reactions. In at least 15 percent of all cases, patients suffer from fever, rashes of the skin or arthralgia. Some patients complain of flank pain. In the chronic form, the patient's condition gradually deteriorates.

The pathology differs depending on the form. In acute interstitial nephritis, the interstitium is altered as an edematous layer. 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 tissue provide detailed information about the cause of the inflammation. In allergic reactions, for example, skin symptoms are common, while eosinophilic granulocytes appear in the tissue.

Diagnosis & course of disease

The laboratory tests for suspected interstitial nephritis include the determination of urea and creatinine. Urine sediment and 24-hour urine collection are indicated. Tubular dysfunction can cause hematuria or proteinuria, hyperphosphaturia, and aminoaciduria or glucosuria. In addition, an increased urine pH or salt loss indicates the disease.

The suspicion of the acute form can be corroborated with evidence of eosinophilia or IgE elevation. In sonography, the acute form again shows an echo-rich and widened parenchyma. The patient's prognosis depends on the form of the disease and the time of diagnosis. The acute form has a relatively favorable prognosis.

Complications

In the worst case, this disease can also lead to death of the patient. Death can occur when the kidneys fail and proper treatment is not instituted. The affected person is then also 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 severe fever and also from discomfort 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 also often lead to mental illnesses or even depression.

Treatment is carried out with the help of drugs. There are no particular complications.However, renal insufficiency must be avoided in any case so that it does not result in a life-threatening condition for the patient. The life expectancy of the person affected may be reduced by the disease. If necessary, the patient can also receive psychological treatment 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 rashes of the skin should see a doctor as soon as possible. Interstitial nephritis must be diagnosed and treated with medication in order to rule out any consequential damage to health. In addition, the disease significantly limits the quality of life. This is why medical advice is required as soon as the first signs of kidney inflammation appear. Those who regularly take antibiotics or have recently contracted a bacterial infection are particularly prone to developing interstitial nephritis.

People with gout, hypercalcaemia or sarcoidosis also belong to the risk groups and should definitely have these symptoms examined. The appropriate doctor is the general practitioner or a nephrologist. In the event of an underlying illness, the responsible doctor is optimally informed. Children should be taken to the pediatrician if they have kidney disease. If psychological complaints have already developed, therapeutic help is also recommended. The sick person should seek comprehensive treatment of physical and mental complaints at an early stage in order to avoid negative health consequences.

Treatment & Therapy

The treatment of tubulo-interstitial 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 agent. If acute kidney failure occurs, hemodialysis takes place. Drug therapy is especially indicated for autoimmune diseases.

Prednisone is often given for immunosuppression. Progress has also been observed in some cases in connection with intravenous or oral corticosteroid therapies. Mycophenolate mofetil has also recently been used for treatment. If the causative agent can be eliminated, more than half of all cases will heal without developing chronic kidney failure.

In the chronic form, the glomeruli of the kidneys are often also affected. For this reason, supportive measures are often used during treatment. This supportive therapy serves to prevent chronic renal failure and is intended to prevent further deterioration in function. Evidence-based treatments are not available.

Outlook & forecast

The prognosis of interstitial nephritis depends on the cause of the disease. Without treatment or therapy, an increase in the symptoms that have arisen can be expected. The general well-being continuously decreases and the symptoms increase. In severe cases, kidney failure can occur. As a result, there is a potential risk to life for 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 quality of life and life expectancy of those affected. The surgical procedure is associated with various complications and side effects. The healing path is lengthy and restrictions 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, in the best case, recovery occurs.

With interstitial nephritis there is a risk of permanent pain and irregularities. In addition, psychological complications can occur due to the strong emotional stress. These worsen the patient's overall prognosis.

prevention

Since interstitial nephritis can have a number of causes, comprehensive prophylaxis is not possible.

Aftercare

What follow-up care for interstitial nephritis looks like depends on the cause of the disease. Since there can be different triggers, there are no clear recommendations for follow-up treatment and prophylaxis. However, as directed by the doctor, patients can take certain measures to encourage therapy.

If there are complaints due to an unsuitable drug, the patient should consider an alternative together with the doctor. There may be side effects and side effects after stopping the drug. The feedback from the doctor enables an improved medication to be put together. If the disease is caused by kidney failure, patients need to take it easy and stay in bed.

Dieting will also help reduce complications and reduce 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 so that they can act quickly in the event of problems.

In the case of a chronic illness, a permanent change in diet is recommended. If necessary, psychotherapeutic advice is useful. This helps those affected to a better self-image and a better quality of life. Patients can also find a self-help group through the doctor or therapist.

You can do that yourself

Interstitial nephritis must first be diagnosed by a doctor. The patient can take some measures to aid medical treatment.

If the symptoms are based on a poorly adjusted drug, this must first be discontinued. The person concerned should then note any side effects and interactions of the prescribed drug and report them to the doctor so that an optimal medication can be achieved quickly. If kidney failure is the cause, rest and bed rest are the main criteria. In addition, the sick person should change their diet in order to avoid pain, dysfunction and other complications. In acute kidney failure, the most important self-help measures are to lead a healthy lifestyle with moderate exercise, a balanced diet and avoidance of stress. Chronic interstitial nephritis requires close monitoring by the responsible physician. In addition, the person affected should adapt their lifestyle to the respective complaints.

Since a chronic illness represents a significant cut in quality of life and well-being, therapeutic advice is often useful. The doctor can also establish contact with other affected persons or a self-help group. In the long term, the symptoms of kidney inflammation can be relieved through dietary measures, rest and drug treatment.