Other glomerulonephritis

Glomerulonephritis is an inflammation that occurs at the level of the glomerulus, the ball of capillaries where the blood that passes through the kidney is filtered, mediated by an immune process. The most common glomerulonephritis in children is postinfectious, mainly the one that occurs after a streptococcal infection at the pharyngo-tonsillar or cutaneous level, while in adults the most common glomerulonephritis is membranous.

Depending on the mechanism of production of glomerular alteration and whether its involvement is acute or chronic, we differentiate several types of glomerulonephritis:

• Post-infectious
• Rapidly progressive
• Minimal changes
• Sclerosing and focal
• Membranous
• Mesangial IgA
• Mesangiocapillary or membranoproliferative

How is it produced?

There are various immunological mechanisms that can trigger glomerulonephritis. Broadly speaking, it is produced either because antibodies are created against parts of the glomerulus structure that the body does not recognize as its own tissue, or because antibodies are created against specific antigens and bind to them, producing what is known as immune complexes, which are deposited in the glomerulus and cause an inflammatory reaction that damages it, or because antibodies are created against antigens that had already been deposited in the glomerulus previously.

In addition to antibodies, it has also been seen that the cells of the body's immune system, such as neutrophils, macrophages or T-type lymphocytes, can trigger these types of immune alterations that damage the glomeruli and cause kidney function impairment.

Symptoms

Symptoms will vary depending on the type of glomerulonephritis you have. The common features that characterize them are the appearance of nephritic syndrome (hematuria, proteinuria, and a decrease in the filtering capacity of the glomerulus) or nephrotic syndrome (proteinuria, edema, a decrease in blood proteins and an increase in blood and urine lipids).

Rapidly progressive glomerulonephritis is an acute condition characterized by nephritic syndrome and degeneration into kidney failure within weeks or months. In 50% of cases it is accompanied by pulmonary hemorrhages, which we know as Goodpasture syndrome. The prognosis is not very favorable and dialysis or kidney transplantation is usually necessary.

Minimal change glomerulonephritis is the leading cause of nephrotic syndrome in childhood. It can be associated with lymphomas, atopy or treatment with non-steroidal anti-inflammatory drugs (NSAIDs). About 25% of children may present with microscopic hematuria. Most progress favorably, although in two-thirds of patients the symptoms may reappear in outbreaks whose frequency decreases with age.

Sclerosing and focal glomerulonephritis affects both children and young adults and can be associated with other kidney disorders, such as damage caused by the use of NSAIDs, heroin, or partial nephrectomies. It presents as a nephrotic syndrome and there may be hematuria, hypertension, or kidney failure. If left untreated, it evolves into chronic kidney failure.

Membranous glomerulonephritis is the most common cause of nephrotic syndrome among adults. It is sometimes associated with microscopic hematuria. In about 50% of cases, a renal vein thrombosis may occur. The course and prognosis are variable, from complete recoveries to progression to renal failure.

IgA mesangial glomerulonephritis, a type of antibody, is typical of adolescents and young adults, especially men. It is associated with affectations of the respiratory or digestive mucosa, as well as Schönlein-Henoch disease and cirrhosis of alcoholic origin. It is characterized by hematuria that can be seen with the naked eye in relation to respiratory infections or physical exertion. In 30% of cases it is associated with high blood pressure. Sometimes there is mild proteinuria and a third of patients may have impaired kidney function.

Mesangiocapillary or membranoproliferative glomerulonephritis is seen primarily in patients younger than 30 years, but is rare. In more than half of the cases nephrotic syndrome appears and in many of them it is associated with hematuria, arterial hypertension and renal failure; occasionally there may be anemia. It progresses slowly to end-stage chronic kidney failure.

Diagnosis

The diagnosis is based on the symptoms, the age group of the affected person and the analytical findings of blood and urine. A patient with a nephrotic syndrome will suggest a post-infectious or rapidly progressive syndrome, while the presence of nephrotic syndrome will point more towards a minimal change syndrome (mainly in children), a focal and segmental one, a membranous one (mainly in adults) or a nephrotic syndrome. membranoproliferative. Isolated hematuria associated with respiratory infections or physical effort will lead to IgA mesangial disease.

In the blood and urine analysis, proteinuria can be seen, at high levels in the case of nephrotic syndrome, and hematuria to a lesser or greater degree if there is nephrotic syndrome. blood casts can be seen in the urine. Kidney function will also be assessed thanks to urea and creatinine levels, which will be more altered depending on the degree of kidney failure.

In case of doubt about the type of glomerulonephritis that the patient suffers, especially in the case of adults, a kidney biopsy can be performed and it will be the observation of the glomerular tissue in the light and electron microscope that will provide the certainty diagnosis.

Treatment

The therapeutic approach will vary depending on the type of glomerulonephritis and the impairment of kidney function. Whenever possible, the root cause of glomerulonephritis will be treated.

At the symptomatic level, measures will be taken to control edema, such as restricting the intake of fluids and salts, as well as the use of diuretics and rest in generalized edema. In the event of high blood pressure, it will be controlled with antihypertensive drugs. The increase in blood fat levels associated with nephrotic syndrome will be controlled with diet and statins if necessary.

As the inflammatory reaction caused by an immune response is common to the different glomerulonephritis, glucocorticoids are used with different responses to try to alleviate said inflammation. In minimal change glomerulonephritis, the response to corticosteroids is very good, making it the treatment of choice in children with nephrotic syndrome. In membranous glomerulonephritis there is a good response in most cases. In others, however, such as membranoproliferative or rapidly progressive glomerulonephritis, the response is not as effective.

In cases that do not respond to corticosteroid treatment, immunosuppressive drugs should be associated, mainly in rapidly progressive glomerulonephritis or in focal sclerosing glomerulonephritis.

In the case of IgA mesangial glomerulonephritis, treatment will be merely symptomatic, with control of hematuria and arterial hypertension, if present.

The progressive deterioration of kidney function may make it necessary to consider dialysis or even kidney transplantation. In the case of rapidly progressive and membranoproliferative glomerulonephritis, the worst prognosis, the involvement may reappear after kidney transplantation in a high percentage of patients.

Precautionary measures

There are not too many preventive measures for this syndrome, but it is always advisable to ensure an adequate intake of water, 1.5-2 liters per day, to promote proper kidney function, and maintain a healthy and balanced diet, low in salt and fat .