Shunt nephritis is a rare disease of the

kidney The kidneys are two reddish-brown bean-shaped organs found in vertebrates. They are located on the left and right in the retroperitoneal space, and in adult humans are about in length. They receive blood from the paired renal arteries; blo ...

that can occur in patients being treated for

hydrocephalus Hydrocephalus is a condition in which an accumulation of cerebrospinal fluid (CSF) occurs within the brain. This typically causes increased pressure inside the skull. Older people may have headaches, double vision, poor balance, urinary inc ...

with a

cerebral shunt A cerebral shunt is a device permanently implanted inside the head and body to drain excess fluid away from the brain. They are commonly used to treat hydrocephalus, the swelling of the brain due to excess buildup of cerebrospinal fluid (CSF). If ...

. It usually results from an infected shunt that produces a long-standing blood infection, particularly by the bacterium '' Staphylococcus epidermidis''. Kidney disease results from an

immune response An immune response is a reaction which occurs within an organism for the purpose of defending against foreign invaders. These invaders include a wide variety of different microorganisms including viruses, bacteria, parasites, and fungi which could ...

that deposits

immune complex An immune complex, sometimes called an antigen-antibody complex or antigen-bound antibody, is a molecule formed from the binding of multiple antigens to antibodies. The bound antigen and antibody act as a unitary object, effectively an antigen o ...

es in the kidney. The most common signs and symptoms of the condition are

blood Blood is a body fluid in the circulatory system of humans and other vertebrates that delivers necessary substances such as nutrients and oxygen to the cells, and transports metabolic waste products away from those same cells. Blood in the cir ...

and

protein Proteins are large biomolecules and macromolecules that comprise one or more long chains of amino acid residues. Proteins perform a vast array of functions within organisms, including catalysing metabolic reactions, DNA replication, res ...

in the

urine Urine is a liquid by-product of metabolism in humans and in many other animals. Urine flows from the kidneys through the ureters to the urinary bladder. Urination results in urine being excreted from the body through the urethra. Cellular ...

anemia Anemia or anaemia (British English) is a blood disorder in which the blood has a reduced ability to carry oxygen due to a lower than normal number of red blood cells, or a reduction in the amount of hemoglobin. When anemia comes on slowly, t ...

, and high blood pressure. Diagnosis is based on these findings in the context of characteristic laboratory values. Treatment includes antibiotics 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.

Presentation

The clinical presentation of shunt nephritis is variable, but the most common manifestations of shunt nephritis include

blood in the urine Hematuria or haematuria is defined as the presence of blood or red blood cells in the urine. “Gross hematuria” occurs when urine appears red, brown, or tea-colored due to the presence of blood. Hematuria may also be subtle and only detectable w ...

, protein in the urine,

, and high blood pressure. Recurrent

fever Fever, also referred to as pyrexia, is defined as having a temperature above the normal range due to an increase in the body's temperature set point. There is not a single agreed-upon upper limit for normal temperature with sources using val ...

, enlarged liver and spleen, and a

skin rash A rash is a change of the human skin which affects its color, appearance, or texture. A rash may be localized in one part of the body, or affect all the skin. Rashes may cause the skin to change color, itch, become warm, bumpy, chapped, dry, cr ...

may also be present. Rarely, the major complaint may be arthritis.

Pathophysiology

Shunt nephritis occurs when a shunt becomes infected with

bacteria Bacteria (; singular: bacterium) are ubiquitous, mostly free-living organisms often consisting of one Cell (biology), biological cell. They constitute a large domain (biology), domain of prokaryotic microorganisms. Typically a few micrometr ...

, most commonly ''Staphylococcus epidermidis''. Bacteria from this infected shunt seed the bloodstream, leading to blood infection ( bacteremia). In response to long-standing infection (months to years), the body mounts an immune response that results in deposition of

es in the kidney, leading to nephritis.

Diagnosis

Urinalysis Urinalysis, a portmanteau of the words ''urine'' and ''analysis'', is a panel of medical tests that includes physical (macroscopic) examination of the urine, chemical evaluation using urine test strips, and microscopic examination. Macroscopic ...

typically demonstrates

hematuria Hematuria or haematuria is defined as the presence of blood or red blood cells in the urine. “Gross hematuria” occurs when urine appears red, brown, or tea-colored due to the presence of blood. Hematuria may also be subtle and only detectable w ...

and

proteinuria Proteinuria is the presence of excess proteins in the urine. In healthy persons, urine contains very little protein; an excess is suggestive of illness. Excess protein in the urine often causes the urine to become foamy (although this symptom ma ...

. Levels of the

complement A complement is something that completes something else. Complement may refer specifically to: The arts * Complement (music), an interval that, when added to another, spans an octave ** Aggregate complementation, the separation of pitch-clas ...

protein C3 are low, while levels of

C-reactive protein C-reactive protein (CRP) is an annular (ring-shaped) pentameric protein found in blood plasma, whose circulating concentrations rise in response to inflammation. It is an acute-phase protein of hepatic origin that increases following interleukin- ...

and

cryoglobulin Cold sensitive antibodies (CSA) are antibodies sensitive to cold temperature. Some cold sensitive antibodies are pathological and can lead to blood disorder. These pathological cold sensitive antibodies include cold agglutinins, Donath–Landstei ...

s may be modestly elevated.

Blood culture A blood culture is a medical laboratory test used to detect bacteria or fungi in a person's blood. Under normal conditions, the blood does not contain microorganisms: their presence can indicate a bloodstream infection such as bacteremia or ...

s and

cerebrospinal fluid Cerebrospinal fluid (CSF) is a clear, colorless body fluid found within the tissue that surrounds the brain and spinal cord of all vertebrates. CSF is produced by specialised ependymal cells in the choroid plexus of the ventricles of the ...

cultures demonstrate '' Staphylococcus epidermidis'', a

coagulase Coagulase is a protein enzyme 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. Importantly, '' S. aureus'' ...

-negative species of '' Staphylococcus''.

Biopsy A biopsy is a medical test commonly performed by a surgeon, interventional radiologist, or an interventional cardiologist. The process involves extraction of sample cells or tissues for examination to determine the presence or extent of a dise ...

of the kidney frequently demonstrates

membranoproliferative glomerulonephritis Membranoproliferative glomerulonephritis (MPGN) is a type of glomerulonephritis caused by deposits in the kidney glomerular mesangium and basement membrane ( GBM) thickening, activating complement and damaging the glomeruli. MPGN accounts for appr ...

, with deposits of C3,

IgM Immunoglobulin M (IgM) is one of several isotypes of antibody (also known as immunoglobulin) that are produced by vertebrates. IgM is the largest antibody, and it is the first antibody to appear in the response to initial exposure to an antig ...

, and

IgG Immunoglobulin G (Ig G) is a type of antibody. Representing approximately 75% of serum antibodies in humans, IgG is the most common type of antibody found in blood circulation. IgG molecules are created and released by plasma B cells. Each IgG ...

Treatment

Management is focused on removing the infectious source. The shunt is removed immediately and antibiotics 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%.

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 epidermidis'' being the infectious agent in 75% of cases.

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 brain to the

atria of the heart The heart is a muscular organ in most animals. This organ pumps blood through the blood vessels of the circulatory system. The pumped blood carries oxygen and nutrients to the body, while carrying metabolic waste such as carbon diox ...

( ventriculoatrial shunts). Less commonly, shunt nephritis has been reported to arise from infections of shunts connecting the ventricular system to the abdominal cavity ( ventriculoperitoneal shunts).{{cite journal , vauthors=Noe HN, Roy S , title=Shunt nephritis , journal=J. Urol. , volume=125 , issue=5 , pages=731–3 , date=May 1981 , pmid=7230350 , doi= 10.1016/S0022-5347(17)55183-6

References

Kidney diseases