Nephritic Syndrome: Symptoms and Treatment

Nephritic Syndrome is a an acute condition marked by inflammation of the kidneys. It has many underlying causes affecting both children and adults. Classically, there are three main features which are thought to define nephritic syndrome.

The Nephritic Syndrome Triad

• Hematuria: This is the presence of blood I the urine. This occurs due to damage to the filtration units in the kidney leading to a leakage of blood cells and proteins.
• Hypertension: The reduced kidney function decreases the filtration of wastes into the urine. The blood pressure goes up due to internal mechanisms to preserve filtration. In late stages, there is volume overload which add to the elevated blood pressure.
• Azotemia: This is a term used to describe the state of elevated urea in the blood. Urea is a toxic waste product that is eliminated by normal kidneys and build up in the body if the kidneys fail.

Causes of Nephritic Syndrome

• Lupus Nephritis: This is one of the most common causes in adults and occurs when the kidneys are involved in a patient with Systemic Lupus Erythematosus (SLE).
• Post Streptococcal Glomerulonephritis: This is a very common cause in young children and occurs following an infection with streptococcus pyogenes (sore throat and skin infections such as impetigo and erysipelas).
• IgA Nephropathy: This is another very common cause in both adults and children occurring due to the deposition of IgA antibodies in the kidney.
• Henoch Schonlein Purpura (HSP): This involves kidney inflammation and is frequently seen in children. It usually presents along with a skin rash and joint pains.
• Hemolytic Uremic Syndrome: This is a condition which occurs more frequently in children, usually after a diarrheal infection with toxin producing bacteria. The toxins damage blood vessel with resultant destruction of blood cells and poor blood supply to the kidney
• Vasculitis: Any of the vasculitic diseases leading to inflammation of the blood vessels can damage the kidney.
• Hepatitis B and C infection: These infections can cause lead to inflammatory conditions in the kidneys.

Symptoms of Nephritic Syndrome

The patient generally experiences the following symptoms:

• Hematuria or blood in the urine
• Oliguria or decreased amount of urine
• Proteinuria which is the passage of proteins in the urine. This may be seen as frothy urine.
• Altered Mental Status which can occur due to build-up of toxins like urea in the blood.
• Skin rash
• Joint pains

Diagnosis of Nephritic Syndrome

It is important to diagnose and treat nephritic syndrome early as it can lead to permanent damage to the kidney. The presence of blood in the urine is an important clue to help with diagnosis. The following investigations can aid with diagnosis.

• Urine routine and microscopy: This includes a rapid dipstick test to test for blood and proteins in the urine. In addition, the urine is examined under a microscope to confirm the presence of blood cells. The type of red cells is also examined.
• Kidney Function Tests: This is a blood test to look at the levels of creatinine and urea, both of which are eliminated by the kidney.
• Complete Blood Count: In some conditions, there may be a decrease in the number of platelets. Other cells may also be abnormal.
• Inflammatory Markers: ESR (Erythrocyte Sedimentation Rate) and CRP (C-Reactive Protein) are often elevated.
• ANA (Anti-Nuclear Antibody) and ANCA (Anti-neutrophil cytoplascmic antibody) levels to look for SLE and vasculitic diseases
• Complement and Immunoglobulin antibody levels: The complement proteins are a part of the immune system. Depending on the underlying cause, there is variable increase and decrease in specific complement proteins and immunoglobulins.
• Hepatitis B and C screening
• Anti-streptococcal antibody titres: ASLO (Antistreptolysin-O) and Anti-DNase B are two antibody titres looked at to establish a prior streptococcal infection
• Kidney Imaging: An ultrasound of the kidney is recommended to help rule out alternate causes of a deteriorating kidney and to look at the size of the kidneys.
• Kidney biopsy: Often, a tissue sample of the kidney is required to establish the diagnosis. This is usually done with ultrasound guidance. Special stains are used while examining the kidney under a regular light microscope. Electron microscopy can also be performed for certain conditions.

Treatment of Nephritic Syndrome

The initial treatment is supportive to help control high blood pressure and to get rid of toxins.

• Antihypertensives: Oral and intravenous medications are used to bring down the blood pressure of the patient.
• Dialysis: Occasionally in severely ill patients, a few sessions of dialysis may be required to help eliminate toxins, remove excess fluid and establish a balance in fluid electrolytes.

Long term treatment depends on the underlying condition. Some conditions like post streptococcal glomerulonephritis may resolve completely with just supportive care. Lupus nephritis on the other hand may require life long use of immune suppressing medications to control inflammation.

References:

• Acute nephritic syndrome: MedlinePlus Medical Encyclopedia [Internet]. [cited 2018 Jul 21]