Shunt nephritis
Encyclopedia
Kidney
The kidneys, organs with several functions, serve essential regulatory roles in most animals, including vertebrates and some invertebrates. They are essential in the urinary system and also serve homeostatic functions such as the regulation of electrolytes, maintenance of acid–base balance, and...
that can occur in patients being treated for hydrocephalus
Hydrocephalus
Hydrocephalus , also known as "water in the brain," is a medical condition in which there is an abnormal accumulation of cerebrospinal fluid in the ventricles, or cavities, of the brain. This may cause increased intracranial pressure inside the skull and progressive enlargement of the head,...
with a cerebral shunt
Cerebral shunt
Cerebral shunts are commonly used to treat hydrocephalus, the swelling of the brain due to excess buildup of cerebrospinal fluid . If left unchecked, the cerebral spinal fluid can build up leading to an increase in intracranial pressure which can lead to intracranial hematoma, cerebral edema,...
. It usually results from an infected shunt that produces a long-standing blood infection, particularly by the bacterium Staphylococcus epidermidis
Staphylococcus epidermidis
Staphylococcus epidermidis is one of thirty-three known species belonging to the genus Staphylococcus. It is part of human skin flora, and consequently part of human flora. It can also be found in the mucous membranes and in animals. Due to contamination, it is probably the most common species...
. Kidney disease results from an immune response that deposits immune complex
Immune complex
An immune complex is formed from the integral binding of an antibody to a soluble antigen. The bound antigen acting as a specific epitope, bound to an antibody is referred to as a singular immune complex....
es in the kidney. The most common signs and symptoms of the condition are blood
Blood
Blood is a specialized bodily fluid in animals that delivers necessary substances such as nutrients and oxygen to the cells and transports metabolic waste products away from those same cells....
and protein
Protein
Proteins are biochemical compounds consisting of one or more polypeptides typically folded into a globular or fibrous form, facilitating a biological function. A polypeptide is a single linear polymer chain of amino acids bonded together by peptide bonds between the carboxyl and amino groups of...
in the urine
Urine
Urine is a typically sterile liquid by-product of the body that is secreted by the kidneys through a process called urination and excreted through the urethra. Cellular metabolism generates numerous by-products, many rich in nitrogen, that require elimination from the bloodstream...
, anemia
Anemia
Anemia is a decrease in number of red blood cells or less than the normal quantity of hemoglobin in the blood. However, it can include decreased oxygen-binding ability of each hemoglobin molecule due to deformity or lack in numerical development as in some other types of hemoglobin...
, and high blood pressure
Hypertension
Hypertension or high blood pressure is a cardiac chronic medical condition in which the systemic arterial blood pressure is elevated. What that means is that the heart is having to work harder than it should to pump the blood around the body. Blood pressure involves two measurements, systolic and...
. Diagnosis is based on these findings in the context of characteristic laboratory values. Treatment includes antibiotic
Antibiotic
An antibacterial is a compound or substance that kills or slows down the growth of bacteria.The term is often used synonymously with the term antibiotic; today, however, with increased knowledge of the causative agents of various infectious diseases, antibiotic has come to denote a broader range of...
s and the prompt removal of the infected shunt. Over half of individuals with shunt nephritis recover completely; most of the remainder have some degree of persistent kidney disease.
Epidemiology
Shunt nephritis is a rare condition affecting males and females of all ages. It occurs in approximately 0.7-2.3% of patients with shunt infections. Approximately 12% of ventriculoatrial shunts become infected, with Staphylococcus epidermidisStaphylococcus epidermidis
Staphylococcus epidermidis is one of thirty-three known species belonging to the genus Staphylococcus. It is part of human skin flora, and consequently part of human flora. It can also be found in the mucous membranes and in animals. Due to contamination, it is probably the most common species...
being the infectious agent in 75% of cases.
Pathophysiology
Shunt nephritis occurs when a shunt becomes infected with bacteriaBacteria
Bacteria are a large domain of prokaryotic microorganisms. Typically a few micrometres in length, bacteria have a wide range of shapes, ranging from spheres to rods and spirals...
, most commonly Staphylococcus epidermidis. Bacteria from this infected shunt seed the bloodstream, leading to blood infection (bacteremia
Bacteremia
Bacteremia is the presence of bacteria in the blood. The blood is normally a sterile environment, so the detection of bacteria in the blood is always abnormal....
). In response to long-standing infection (months to years), the body mounts an immune response that results in deposition of immune complex
Immune complex
An immune complex is formed from the integral binding of an antibody to a soluble antigen. The bound antigen acting as a specific epitope, bound to an antibody is referred to as a singular immune complex....
es in the kidney, leading to nephritis
Nephritis
Nephritis is inflammation of the nephrons in the kidneys. The word "nephritis" was imported from Latin, which took it from Greek: νεφρίτιδα. The word comes from the Greek νεφρός - nephro- meaning "of the kidney" and -itis meaning "inflammation"....
.
Clinical manifestations
The clinical presentation of shunt nephritis is variable, but the most common manifestations of shunt nephritis include blood in the urineHematuria
In medicine, hematuria, or haematuria, is the presence of red blood cells in the urine. It may be idiopathic and/or benign, or it can be a sign that there is a kidney stone or a tumor in the urinary tract , ranging from trivial to lethal...
, protein in the urine
Proteinuria
Proteinuria means the presence of anexcess of serum proteins in the urine. The protein in the urine often causes the urine to become foamy, although foamy urine may also be caused by bilirubin in the urine , retrograde ejaculation, pneumaturia due to a fistula, or drugs such as pyridium.- Causes...
, anemia
Anemia
Anemia is a decrease in number of red blood cells or less than the normal quantity of hemoglobin in the blood. However, it can include decreased oxygen-binding ability of each hemoglobin molecule due to deformity or lack in numerical development as in some other types of hemoglobin...
, and high blood pressure
Hypertension
Hypertension or high blood pressure is a cardiac chronic medical condition in which the systemic arterial blood pressure is elevated. What that means is that the heart is having to work harder than it should to pump the blood around the body. Blood pressure involves two measurements, systolic and...
. Recurrent fever
Fever
Fever is a common medical sign characterized by an elevation of temperature above the normal range of due to an increase in the body temperature regulatory set-point. This increase in set-point triggers increased muscle tone and shivering.As a person's temperature increases, there is, in...
, enlarged liver and spleen
Hepatosplenomegaly
Hepatosplenomegaly is the simultaneous enlargement of both the liver and the spleen . Hepatosplenomegaly can occur as the result of acute viral hepatitis or infectious mononucleosis, or it can be the sign of a serious and life threatening lysosomal storage disease...
, and a skin rash
Purpura
Purpura is the appearance of red or purple discolorations on the skin that do not blanch on applying pressure. They are caused by bleeding underneath the skin...
may also be present. Rarely, the major complaint may be arthritis
Arthritis
Arthritis is a form of joint disorder that involves inflammation of one or more joints....
.
Urinalysis
Urinalysis
A urinalysis , also known as Routine and Microscopy , is an array of tests performed on urine, and one of the most common methods of medical diagnosis...
typically demonstrates hematuria
Hematuria
In medicine, hematuria, or haematuria, is the presence of red blood cells in the urine. It may be idiopathic and/or benign, or it can be a sign that there is a kidney stone or a tumor in the urinary tract , ranging from trivial to lethal...
and proteinuria
Proteinuria
Proteinuria means the presence of anexcess of serum proteins in the urine. The protein in the urine often causes the urine to become foamy, although foamy urine may also be caused by bilirubin in the urine , retrograde ejaculation, pneumaturia due to a fistula, or drugs such as pyridium.- Causes...
. Levels of the complement
Complement system
The complement system helps or “complements” the ability of antibodies and phagocytic cells to clear pathogens from an organism. It is part of the immune system called the innate immune system that is not adaptable and does not change over the course of an individual's lifetime...
protein C3 are low, while levels of C-reactive protein
C-reactive protein
C-reactive protein is a protein found in the blood, the levels of which rise in response to inflammation...
and cryoglobulins may be modestly elevated. Blood culture
Blood culture
Blood culture is a microbiological culture of blood. It is employed to detect infections that are spreading through the bloodstream...
s and cerebrospinal fluid
Cerebrospinal fluid
Cerebrospinal fluid , Liquor cerebrospinalis, is a clear, colorless, bodily fluid, that occupies the subarachnoid space and the ventricular system around and inside the brain and spinal cord...
cultures demonstrate Staphylococcus epidermidis
Staphylococcus epidermidis
Staphylococcus epidermidis is one of thirty-three known species belonging to the genus Staphylococcus. It is part of human skin flora, and consequently part of human flora. It can also be found in the mucous membranes and in animals. Due to contamination, it is probably the most common species...
, a coagulase
Coagulase
Coagulase is a protein produced by several microorganisms that enables the conversion of fibrinogen to fibrin. In the laboratory, it is used to distinguish between different types of Staphylococcus isolates. Coagulase negativity excludes S. aureus. That is to say, S...
-negative species of Staphylococcus
Staphylococcus
Staphylococcus is a genus of Gram-positive bacteria. Under the microscope they appear round , and form in grape-like clusters....
. Biopsy
Biopsy
A biopsy is a medical test involving sampling of cells or tissues for examination. It is the medical removal of tissue from a living subject to determine the presence or extent of a disease. The tissue is generally examined under a microscope by a pathologist, and can also be analyzed chemically...
of the kidney frequently demonstrates membranoproliferative glomerulonephritis
Membranoproliferative glomerulonephritis
Membranoproliferative glomerulonephritis , also known as mesangiocapillary glomerulonephritis, is a type of glomerulonephritis caused by deposits in the kidney glomerular mesangium and basement membrane thickening, activating complement and damaging the glomeruli.MPGN accounts for approximately 4%...
, with deposits of C3, IgM
IGM
IGM as an acronym or abbreviation can refer to:* Immunoglobulin M , the primary antibody against A and B antigens on red blood cells* International Grandmaster, a chess ranking* intergalactic medium* Intragroup medium - see: Intracluster medium...
, and IgG.
Treatment
Management is focused on removing the infectious source. The shunt is removed immediately and antibioticAntibiotic
An antibacterial is a compound or substance that kills or slows down the growth of bacteria.The term is often used synonymously with the term antibiotic; today, however, with increased knowledge of the causative agents of various infectious diseases, antibiotic has come to denote a broader range of...
s are begun. The infected shunt, typically a ventriculoatrial shunt, may be replaced with a ventriculoperitoneal shunt.
Prognosis
In one review, over half of individuals with shunt nephritis made a complete recovery. An additional 40% of individuals had persistent urine abnormalities or end-stage renal disease. Death occurred in 9%.History
Shunt nephritis was first described by Black in 1965. Early cases and most cases since then are associated with infections of shunts that connect the ventricular system of the brainVentricular system
The ventricular system is a set of structures containing cerebrospinal fluid in the brain. It is continuous with the central canal of the spinal cord.-Components:The system comprises four ventricles:* right and left lateral ventricles* third ventricle...
to the atria of the heart (ventriculoatrial shunts). Less commonly, shunt nephritis has been reported to arise from infections of shunts connecting the ventricular system to the abdominal cavity
Abdominal cavity
The abdominal cavity is the body cavity of the human body that holds the bulk of the viscera. It is located below the thoracic cavity, and above the pelvic cavity. Its dome-shaped roof is the thoracic diaphragm , and its oblique floor is the pelvic inlet...
(ventriculoperitoneal shunts).