Nephritis is a term used to describe inflammation of the kidney, while glomerulonephritis (GN) is a condition in which the small renal corpuscles called glomeruli become inflamed.
The consequence of glomerulonephritis is the excretion of red blood cells and protein in the urine, these cells normally circulate only in the blood.
The glomeruli filter excess fluids, electrolytes and waste products from the blood and carry them into the urine.
If this kidney disease is not treated or does not respond to treatment, it can lead to gradual destruction of the glomeruli.
This leads to kidney failure, as the kidneys are no longer able to purify the blood.
Acute GN is characterized by sudden inflammation, whereas chronic GN develops gradually.
Glomerulonephritis can be a primary disease or part of a systemic disease such as diabetes or lupus.
Contents
Types of acute nephritis
Tubulointerstitial nephritis
In interstitial nephritis, the spaces between the renal tubules that produce urine become inflamed.
Due to the inflammation, the kidneys swell. There is a variant, uric acid nephritis, in which the problem is due to an accumulation of uric acid.
Pyelonephritis
Pyelonephritis is an infection that originates in the bladder (cystitis), rises through the ureters (causing urethritis) and spreads to the kidneys.
The infection can be caused by bacteria, viruses or fungi.
Pregnant women and children have an increased risk of developing pyelonephritis.
The ureters are two tubes that carry urine from the two kidneys to the bladder, the muscular organ where urine is collected, until it is finally excreted from the body through the urethra.
Glomerulonephritis
Glomerulonephritis is a condition that triggers inflammation of the glomeruli and can be caused by:
- Heredity;
- Medication;
- autoimmune reactions.
Glomeruli are tiny capillaries through which blood is transported and which act as a filtering unit.
Inflamed and damaged glomeruli can no longer filter the blood properly.
Classification based on tissue changes (histology)
Usually, a pathological classification is used, which is determined by light microscopy, but immunofluorescence and electron microscopy can provide additional information and help to understand the history of its formation.
Focal segmental glomerulosclerosis
Some glomeruli have segmental fibrosis.
In children and adults, this is a common cause of nephritic syndrome; it can occur in association with hematuria (blood in the urine), high blood pressure, and impaired kidney function.
Approximately 50% of patients respond to treatment with a cycle of high-dose prednisolone, although treatment for up to 4 months is often required in adults. If this does not bring success, some patients may respond positively to the addition of cyclophosphamide and cyclosporine can be used to lower the proteins in the urine.
In up to 50% of patients, the disease progresses to end-stage kidney failure within a few years, but the process can be stopped with corticosteroid treatment.
The variant known as collapsing glomerulopathy occurs in conjunction with HIV infection.
Mesangiocapillary glomerulonephritis
It is also called membranoproliferative glomerulonephritis (MPGN).
This leads to the proliferation of mesangium cells, the growth of the mesangial matrix and the thickening of the glomerular basement membrane.
It can be divided according to its appearance under the electron microscope.
The secondary forms of the disease develop in association with hepatitis C (with or without cryoglobulins), other chronic infections, and lupus.
Often, therapy consists of administering corticosteroids.
About 50% of patients develop renal insufficiency within ten years.
Mesangioproliferative nephritis
There is the proliferation of mesangium cells (which are located around the capillaries of the glomeruli) and the expansion of the matrix.
It is usually observed in IgA nephropathy (IgA deposition) and lupus nephritis (caused by the autoimmune disease lupus).
Other components of immunoglobulins (antibodies) may also be present.
IgA nephropathy (Berger’s disease) often occurs together with macrohematuria (presence of blood in the urine visible to the naked eye), which can develop in a few days from an infection of the upper respiratory tract.
Asymptomatic hematuria and/or proteinuria are also noted and may occur with nephrosis or nephrotic symptoms.
Men are more likely to be affected.
Risk factors include HLA B35 and D4 antigens, celiac disease, alcoholic liver disease, and HIV.
Some studies suggest that a cycle of high-dose prednisolone may curb proteinuria and delay kidney failure.
In patients with impaired renal function, immunosuppressants are often administered.
Even if the disease progresses slowly, 20-30% of patients can develop end-stage kidney failure. This is rather rare in children, but is more common in adults.
The kidney lesions in Schönlein-Henoch purpura are similar to IgA nephropathy and may be a variant of this disease. 20% of patients develop renal failure and 5% end-stage renal failure.
Proliferative, focal segmental glomerulonephritis
It is usually a secondary consequence of systemic diseases such as lupus and Alport syndrome.
It often occurs together with segmental necrosis of the capillary loops (arterioles that form a kind of tangle), followed by the formation of crescents.
The term crescent glomerulonephritis is used when there is a cluster of cells inside the Bowman’s capsule.
Diffuse proliferative glomerulonephritis
Diffuse hypercellularity occurs, which is caused by the infiltration of the inflammatory cells and the proliferation of endothelial cells or mesangium cells.
Generally, there is a deposition of immunoglobulins and complement around the capillary loops.
It presents with acute nephrotic syndrome two or more weeks after infection.
It is usually caused by a streptococcal infection.
Almost all children recover without treatment (with the exception of antibiotics for the infection), but a small percentage of adults may develop renal insufficiency.
Membranous nephritis
There is a diffuse thickening of the glomerular basement membrane.
Immunofluorescence shows granular deposits of immunoglobulins.
Membranous nephropathy can be idiopathic or, rarely, secondary caused by lupus, hepatitis B, a tumor, the use of gold or penicillin.
It is more common in men.
In adults, it is the most common cause of nephrotic syndrome. It can show up with very high levels of protein in the urine or nephrotic syndrome and high blood pressure. Hematuria is rare.
The idiopathic form may respond to therapy, which involves the monthly alternating administration of corticosteroids with chlorambucil, cyclophosphamide or cyclosporine.
In 30-50% of patients, end-stage renal failure develops.
The remaining percentages with membranous nephropathy undergo spontaneous complete or partial remission of nephrotic syndrome with stable renal function.
Glomerulonephritis with crescent formation
This can be part of the development of some forms of primary glomerulonephritis (for example, IgA nephropathy or mesangiocapillary glomerulonephritis), but often it is observed in diseases such as Goodpasture’s syndrome, systemic vasculitis and lupus nephritis.
Idiopathic glomerulonephritis with crescent formation is considered a form of renal ANCA-associated vasculitis (anti-neutrophilic cytoplasmic antibodies).
It manifests itself with the clinical syndrome of rapidly progressive glomerulonephritis.
In the absence of treatment, the disease progresses within a few months to end-stage renal failure.
In general, prednisolone and cyclophosphamide work well in humans before irreversible kidney damage occurs.
Goodpasture syndrome
It is caused by autoantibodies that target the alpha-3 chain of type IV collagen, a structural component of the glomerular basement membrane.
50% of patients develop bleeding in the lungs.
The syndrome presents with rapidly progressive glomerulonephritis, and if not treated, it usually leads to kidney failure within six months.
As a rule, therapy based on prednisolone, cyclophosphamide and plasmapheresis, that is, the separation of the liquid component from the solid component of the blood (white and red blood cells and platelets), is effective in the early stages of this kidney disease.
Recurrences are very rare and the long-term prognosis after successful treatment is good.
Possible causes of nephritis
Many diseases can cause glomerulonephritis.
Nevertheless, sometimes the cause remains unknown.
Diseases that can cause inflammation of the renal corpuscles include:
Bacterial infections
Poststreptococcal glomerulonephritis.
Glomerulonephritis can develop as follows:
- a week or two after recovering from a streptococcal infection in the throat
- from an infection of the skin, such as impetigo (rarely)
- from bacterial endocarditis
Viral infections. Infections caused by viruses, such as the human immunodeficiency virus (HIV), hepatitis B and C, can cause glomerulonephritis.
Immune disorders
- Lupus
- Goodpasture syndrome
- IgA nephropathy
- Vasculitis
- Polyarteritis
- Wegener’s granulomatosis (progressive and characterized by rapidly necrotizing crescents)
Diseases that can cause glomerular lesions
- Hypertension
- Diabetic nephropathy
- Focal segmental glomerulosclerosis
Symptoms of nephritis and glomerulonephritis
Usually, the symptoms depend on the type of GN, acute or chronic.
The first sign of this disease can be found in the results of a routine urine test.
Some of the first signs are:
- frothy urine due to the presence of proteins (known as proteinuria);
- brown, rusty or dark urine, which indicates the presence of red blood cells;
- less frequent urination.
Indicators of chronic renal insufficiency, which can develop gradually, include:
- unwanted weight loss;
- nausea and vomiting;
- Indisposition;
- Headache;
- Fatigue;
- general itching;
- frequent bouts of hiccups;
- nocturnal urge to urinate;
- bleeding or slight formation of bruises;
- loss of attention;
- lethargy and drowsiness;
- confusion and delirium;
- Coma;
- muscle spasms;
- muscle spasms;
- uremic syndrome (accumulation of nitrogenous substances in the blood, especially urea);
- hyperpigmentation (the skin appears brown or yellow);
- impaired sensitivity in the feet, hands or other areas.
Some other symptoms associated with this disease include:
- Nosebleed;
- excessive amount of urine;
- blood in vomit or stool;
- Hypertension.
Interstitial nephritis caused by medication can cause fever, joint pain, rash, and back pain.
Diagnosis of nephritis
The tests used to diagnose nephrotic syndrome include:
Urinalysis
Urinalysis may reveal the presence of red blood cells in the urine, which indicates possible glomerular damage. The results may also show leukocytes, which are indicators of infection or inflammation and proteinuria as a result of damage to the nephron.
Blood tests
Blood tests provide information about kidney damage by measuring the amounts of excretory products such as creatinine or urea nitrogen in the blood (azotemia).
Device diagnostics
The doctor can order instrumental examinations such as X-rays, ultrasound or CT scans, which allow imaging of the kidneys.
Kidney biopsy
This procedure involves the use of a special needle to take small samples of tissue from the kidney, which are examined under a microscope. In this way, the cause of the inflammation can be determined. A biopsy is almost always required to support the diagnosis of nephritis.
Therapies and medications for nephritis and glomerulonephritis
Some cases of acute glomerulonephritis (especially if it was preceded by streptococcal infection) heal on their own, and often treatment is not required.
Therapy of arterial hypertension
To protect the kidneys, it is important to control blood pressure.
To bring hypertension under control and slow down the loss of kidney function, the doctor may prescribe the following medications:
- Diuretics
- Angiotensin-converting enzyme (ACE) inhibitors
- Angiotensin II receptor blockers
Natural remedies for high blood pressure include a healthy diet and regular exercise.
Therapy for associated renal failure
In acute glomerulonephritis and acute renal failure, dialysis removes excess fluid and controls high blood pressure.
In the case of end-stage kidney disease, the only long-term therapies are dialysis and kidney transplantation.
Dialysis is the only treatment option when a transplant is not possible, usually due to poor health.
Diet and nutrition
A healthy diet is essential so as not to overwhelm the kidneys. Therefore, one should eat a lot of fruits and vegetables and better avoid meat, dairy products, eggs and fried foods.
How long does recovery take? Prognosis for patients with nephritis and glomerulonephritis
Expectations are different depending on whether the nephritis is acute or chronic.
If the disease was caused by an infection, it will pass as soon as the bacteria are defeated.
If nephritis is chronic, it has already damaged the glomeruli or tubules and the patient suffers from renal insufficiency. It is not possible to completely cure it, which is why therapy is aimed at relieving symptoms.
