A good million renal corpuscles (glomeruli) in each kidney are responsible for filtering about 180 liters of primary urine from the liter of blood that flows through them per minute, day after day, from which just under 2 liters of final urine is concentrated along with metabolic waste products. In addition to detoxification, the kidney is important for the regulation of water and salt balance, blood pressure regulation, red blood cell formation and bone metabolism. Inflammatory processes can have a massive impact on overall kidney function.
What is glomerulonephritis?
Glomerulonephritis is inflammation of kidney tissue that affects both kidneys and initially occurs in the renal corpuscles, but can then spread to the rest of the kidney tissue. It can be brief and severe (acute glomerulonephritis), rapidly progressive (rapid progressive), or slow and insidious (chronic glomerulonephritis). In most cases, the immune system is involved. It is assumed that the constant contact of the vascular tangles in the renal corpuscles with the harmful substances in the blood leads to an inflammatory reaction – why this is the case in some people but not in others is still largely unclear. However, scientists believe that hereditary factors play a role.
What are the different forms?
Due to the large number of different forms of inflammation, the disease is very diverse and can only be assessed by a kidney specialist. It is important to differentiate the forms from each other, as they progress and are treated differently and also differ in terms of their prognosis. The classification can be made on the basis of symptoms, causes, mechanism of development, and type of tissue changes, and the technical name of each form is usually based on the course and location of the primary damage (e.g., extracapillary or membranous glomerulonephritis).
- One criterion is in what form the immune system is involved. In a large group, immune complexes are formed, i.e., compounds of antigens and antibodies. These may be formed as a result of other diseases (e.g., after streptococcal throat infection) by antibodies formed against bacterial antigens, which first circulate in the blood and then deposit at various sites in the renal corpuscles, damaging them. In other forms, the organism forms autoantibodies against the inner layer of the renal corpuscles, which are deposited there. However, other cells of the immune system (eg, T cells, complement) can also trigger inflammatory reactions.
- Another distinguishing feature is whether the inflammation initially only runs on the kidney (primary form) or occurs in the context of systemic diseases that also affects other organs (eg, the connective tissue in collagenoses or the lungs in Goodpasture’s syndrome), cancers, infections or with certain drugs (secondary form).
Symptoms and diagnosis
Whether, how and when the disease manifests itself depends on the type of inflammation. In very many cases, those affected do not feel any symptoms for a long time, although the damage to the kidney is already proceeding. Later, the symptoms of progressive kidney failure become apparent, e.g. loss of performance and malaise, loss of appetite, water retention, cardiac arrhythmia and high blood pressure, but also nausea, bad breath, itching and yellowish discoloration of the skin. Bone softening, increased susceptibility to infections, anemia, impaired concentration and headaches may occur. Some patients also complain of kidney pain. Blood, protein and so-called urine cylinders can be detected in the urine, and altered kidney values (creatinine) in the blood. Further examinations include ultrasound of the kidneys and kidney function tests. For the diagnosis and assignment of the form of inflammation, the removal of tissue samples from the kidney is ultimately necessary. In order to make the diagnosis and start therapy as early as possible, it is important to perform urine tests in potential risk groups. For example, a urine test should be performed 1-3 weeks after a streptococcal throat infection. Periodic screening for blood and protein in the urine should also be performed for systemic diseases that may lead to secondary G.
Therapy and treatment
Therapy depends on the nature of the inflammation. If an underlying disease is present, it is treated, for example, tonsillitis with antibiotics. Otherwise, antihypertensive drugs, cortisone, and immunosuppressants are available.Depending on the extent of the kidney failure, the affected person must undergo “blood washing” (dialysis) and change his or her diet and fluid intake. The course varies from forms with spontaneous recovery, to those with inconsequential recovery with early therapy, to forms in which kidney failure requiring dialysis occurs within 5 years or even a few months. Kidney pain: what is the underlying cause?
