Renal biopsy

kidney biopsyComplications
While renal biopsy is not indicated in all cases of haematuria, it may be performed in those with glomerular haematuria (blood that is thought to come from damage to the glomerulus) or when combined with features of progressive renal disease (e.g. increasing proteinuria, elevated blood pressure and kidney failure). One example is the nephritic syndrome. Proteinuria (or protein in the urine) occurs in many renal conditions. Renal biopsy is usually reserved for patients with high or increasing levels of proteinuria, or for patients who have proteinuria along with other signs of renal dysfunction. One example is the nephrotic syndrome.

Kidney failure

renal failurekidney problemsrenal impairment
Causes of acute kidney failure include low blood pressure, blockage of the urinary tract, certain medications, muscle breakdown, and hemolytic uremic syndrome. Causes of chronic kidney failure include diabetes, high blood pressure, nephrotic syndrome, and polycystic kidney disease. Diagnosis of acute failure is often based on a combination of factors such as decrease urine production or increased serum creatinine. Diagnosis of chronic failure is based on a glomerular filtration rate (GFR) of less than 15 or the need for renal replacement therapy. It is also equivalent to stage 5 chronic kidney disease. Treatment of acute failure depends on the underlying cause.

Lupus nephritis

systemic lupus erythematosus
Clinically, haematuria and proteinuria are present, frequently with nephrotic syndrome, hypertension, hypocomplementemia, elevated anti-dsDNA titres and elevated serum creatinine. Class V disease (membranous glomerulonephritis) is characterized by diffuse thickening of the glomerular capillary wall (segmentally or globally), with diffuse membrane thickening, and subepithelial deposits seen under the electron microscope. Clinically, stage V presents with signs of nephrotic syndrome. Microscopic haematuria and hypertension may also been seen. Stage V can also lead to thrombotic complications such as renal vein thromboses or pulmonary emboli.

Urinary cast

urinary castscastsRBC casts
They can also be associated with renal infarction and subacute bacterial endocarditis. They are a yellowish-brown color and are generally cylindrical with sometimes ragged edges; their fragility makes inspection of a fresh sample necessary. They are usually associated with nephritic syndromes or urinary tract injury. Indicative of inflammation or infection, the presence of white blood cells within or upon casts strongly suggests pyelonephritis, a direct infection of the kidney. They may also be seen in inflammatory states, such as acute allergic interstitial nephritis, nephrotic syndrome, or post-streptococcal acute glomerulonephritis.

Creatinine

serum creatininenormal kidney functioncreatinin
Cystatin C – novel marker of kidney function. Jaffe reaction – an example of creatinine assay methodology. Rhabdomyolysis – may be diagnosed using creatinine levels. Nephrotic syndrome. Creatinine at Lab Tests Online. Creatinine: analyte monograph – The Association for Clinical Biochemistry and Laboratory Medicine.

Urine

urinaryhuman urinepiss
The urinary system consists of the kidneys, ureters, urinary bladder, and urethra. The system produces urine by a process of filtration, reabsorption, and tubular secretion. The kidneys extract the soluble wastes from the bloodstream, as well as excess water, sugars, and a variety of other compounds. The resulting urine contains high concentrations of urea and other substances, including toxins. Urine flows from the kidneys through the ureter, bladder, and finally the urethra before passing from the body. Research looking at the duration of urination in a range of mammal species found that nine larger species urinated for 21 ± 13 seconds irrespective of body size.

Nephritic syndrome

Acute nephritic syndromechronic nephritisChronic nephritic syndrome
Nephritic syndrome is a syndrome comprising signs of nephritis, which is kidney disease involving inflammation. It often occurs in glomerulonephritis, which is characterized by a thin glomerular basement membrane and small pores in the podocytes of the glomerulus, large enough to permit proteins and red blood cells to pass into the urine (yielding proteinuria and hematuria). By contrast, nephrotic syndrome is characterized by only proteins moving into the urine. Nephritic syndrome, like nephrotic syndrome, may involve hypoalbuminemia due to the protein albumin moving from the blood to the urine.

Minimal change disease

lipoid nephrosisMinimal change lesionminimal change nephropathy
Minimal change disease (also known as MCD, minimal change glomerulopathy, and nil disease, among others) is a disease affecting the kidneys which causes a nephrotic syndrome. Nephrotic syndrome leads to the loss of significant amounts of protein in the urine, which causes the widespread oedema (soft tissue swelling) and impaired kidney function commonly experienced by those affected by the disease. It is most common in children and has a peak incidence at 2 to 6 years of age. MCD is responsible for 10-25% of nephrotic syndrome cases in adults. It is also the most common cause of nephrotic syndrome of unclear cause (idiopathic) in children.

Peritoneum

peritonealintraperitonealparietal peritoneum
Some structures, such as the kidneys, are "primarily retroperitoneal", while others such as the majority of the duodenum, are "secondarily retroperitoneal", meaning that structure developed intraperitoneally but lost its mesentery and thus became retroperitoneal. The peritoneum develops ultimately from the mesoderm of the trilaminar embryo. As the mesoderm differentiates, one region known as the lateral plate mesoderm splits to form two layers separated by an intraembryonic coelom. These two layers develop later into the visceral and parietal layers found in all serous cavities, including the peritoneum.

Nephron

renal tubulenephronsrenal tubules
The nephron (from Greek νεφρός – nephros, meaning "kidney") is the microscopic structural and functional unit of the kidney. It is composed of a renal corpuscle and a renal tubule. The renal corpuscle consists of a tuft of capillaries called a glomerulus and an encompassing Bowman's capsule. The renal tubule extends from the capsule. The capsule and tubule are connected and are composed of epithelial cells with a lumen. A healthy adult has 0.8 to 1.5 million nephrons in each kidney. Blood is filtered as it passes through three layers: the endothelial cells of the capillary wall, its basement membrane, and between the foot processes of the podocytes of the lining of the capsule.

Adrenal gland

adrenal glandsadrenalsuprarenal gland
The adrenal glands are located on both sides of the body in the retroperitoneum, above and slightly medial to the kidneys. In humans, the right adrenal gland is pyramidal in shape, whereas the left is semilunar or crescent shaped and somewhat larger. The adrenal glands measure approximately 3 cm in width, 5.0 cm in length, and up to 1.0 cm in thickness. Their combined weight in an adult human ranges from 7 to 10 grams. The glands are yellowish in colour. The adrenal glands are surrounded by a fatty capsule and lie within the renal fascia, which also surrounds the kidneys. A weak septum (wall) of connective tissue separates the glands from the kidneys.

Electrolyte

electrolyteselectrolyticionic solution
The interpretation of these values is somewhat meaningless without analysis of the clinical history and is often impossible without parallel measurements of renal function. The electrolytes measured most often are sodium and potassium. Chloride levels are rarely measured except for arterial blood gas interpretations, since they are inherently linked to sodium levels. One important test conducted on urine is the specific gravity test to determine the occurrence of an electrolyte imbalance.

Kidney transplantation

kidney transplantrenal transplantationrenal transplant
Kidney transplantation or renal transplantation is the organ transplant of a kidney into a patient with end-stage renal disease. Kidney transplantation is typically classified as deceased-donor (formerly known as cadaveric) or living-donor transplantation depending on the source of the donor organ. Living-donor renal transplants are further characterized as genetically related (living-related) or non-related (living-unrelated) transplants, depending on whether a biological relationship exists between the donor and recipient. Exchanges and chains are a novel approach to expand the living donor pool.

Renin–angiotensin system

renin–angiotensin–aldosterone systemrenin-angiotensin-aldosterone systemrenin angiotensin system
When renal blood flow is reduced, juxtaglomerular cells in the kidneys convert the precursor prorenin (already present in the blood) into renin and secrete it directly into circulation. Plasma renin then carries out the conversion of angiotensinogen, released by the liver, to angiotensin I. Angiotensin I is subsequently converted to angiotensin II by the angiotensin-converting enzyme (ACE) found on the surface of vascular endothelial cells, predominantly those of the lungs. Angiotensin II is a potent vasoconstrictive peptide that causes blood vessels to narrow, resulting in increased blood pressure.

Dialysis

kidney dialysisrenal dialysisdialysis machine
In medicine, dialysis (from Greek διάλυσις, Dialysis, "dissolution"; from διά, dia, "through", and λύσις, lysis, "loosening or splitting") is the process of removing excess water, solutes, and toxins from the blood in people whose kidneys can no longer perform these functions naturally. This is referred to as renal replacement therapy. Dialysis is used in patients with rapidly developing loss of kidney function, called acute kidney injury (previously called acute renal failure), or slowly worsening kidney function, called Stage 5 chronic kidney disease, (previously called chronic kidney failure and end-stage renal disease and end-stage kidney disease).

Diabetic nephropathy

diabetic kidney diseasenephropathydiabetic nephropathies
Diabetic nephropathy (DN), also known as diabetic kidney disease, is the chronic loss of kidney function occurring in those with diabetes mellitus. Protein loss in the urine due to damage to the glomeruli may become massive, and cause a low serum albumin with resulting generalized body swelling (edema) and result in the nephrotic syndrome. Likewise, the estimated glomerular filtration rate (eGFR) may progressively fall from a normal of over 90 ml/min/1.73m 2 to less than 15, at which point the patient is said to have end-stage kidney disease (ESKD). It usually is slowly progressive over years.

Clinical urine tests

urinalysisurine testurine sample
A sodium-related parameter is fractional sodium excretion, which is the percentage of the sodium filtered by the kidney which is excreted in the urine. It is a useful parameter in acute kidney failure and oliguria, with a value below 1% indicating a prerenal disease and a value above 3% indicating acute tubular necrosis or other kidney damage. Urine may be tested to determine whether an individual has engaged in recreational drug use. In this case, the urinalysis would be designed to detect whatever marker indicates drug use.

Nephrology

nephrologistrenal medicinekidney disease
Nephrology (from Greek nephros "kidney", combined with the suffix -logy, "the study of") is a specialty of medicine and pediatric medicine that concerns itself with the kidneys: the study of normal kidney function and kidney disease, the preservation of kidney health, and the treatment of kidney disease, from diet and medication to renal replacement therapy (dialysis and kidney transplantation). Nephrology also studies systemic conditions that affect the kidneys, such as diabetes and autoimmune disease; and systemic diseases that occur as a result of kidney disease, such as renal osteodystrophy and hypertension.

Renal function

glomerular filtration ratekidney functioncreatinine clearance
The most relevant assessments in a renal ultrasound are renal sizes, echogenicity and any signs of hydronephrosis. Renal enlargement usually indicates diabetic nephropathy, focal segmental glomerular sclerosis or myeloma. Renal atrophy suggests longstanding chronic renal disease. Risk factors for kidney disease include diabetes, high blood pressure, family history, older age, ethnic group and smoking. For most patients, a GFR over 60 mL/min/1.73m 2 is adequate. But significant decline of the GFR from a previous test result can be an early indicator of kidney disease requiring medical intervention.

Blood pressure

systolic blood pressurediastolic blood pressurearterial blood pressure
This system allows the kidney to compensate for loss in blood volume or drops in arterial pressure by activating an endogenous vasoconstrictor known as angiotensin II. Aldosterone release: This steroid hormone is released from the adrenal cortex in response to angiotensin II or high serum potassium levels. Aldosterone stimulates sodium retention and potassium excretion by the kidneys. Since sodium is the main ion that determines the amount of fluid in the blood vessels by osmosis, aldosterone will increase fluid retention, and indirectly, arterial pressure.

Cancer

cancersmalignanciescancerous
Currently, targeted therapies exist for many of the most common cancer types, including bladder cancer, breast cancer, colorectal cancer, kidney cancer, leukemia, liver cancer, lung cancer, lymphoma, pancreatic cancer, prostate cancer, skin cancer, and thyroid cancer as well as other cancer types. The efficacy of chemotherapy depends on the type of cancer and the stage. In combination with surgery, chemotherapy has proven useful in cancer types including breast cancer, colorectal cancer, pancreatic cancer, osteogenic sarcoma, testicular cancer, ovarian cancer and certain lung cancers.

Hypoalbuminemia

hypoalbuminaemiaLow albuminlow blood albumin levels
After renal biopsy, these syndromes are commonly diagnosed as minimal change disease, membranoproliferative glomerulonephritis, or focal segmental glomerulosclerosis. In adults, on the other hand, nephrotic syndrome is commonly a secondary disease process due to a variety of inciting factors. These inciting factors can be diverse, including toxins, drugs, heavy metals, autoantibodies, post-infectious antibody complexes, or immune complexes formed after malignancies like multiple myeloma. Albuminuria and resultant hypoalbuminemia can also occur in chronic kidney disease without protein loss levels as high as seen in nephrotic syndrome.

Proteinuria

protein in the urineproteinIsolated proteinuria
Nephrotic syndromes (i.e. intrinsic renal failure). Pre-eclampsia. Eclampsia. Toxic lesions of kidneys. Amyloidosis. Collagen vascular diseases (e.g. systemic lupus erythematosus). Dehydration. Glomerular diseases, such as membranous glomerulonephritis, focal segmental glomerulonephritis, minimal change disease (lipoid nephrosis). Strenuous exercise. Stress. Benign orthostatic (postural) proteinuria. Focal segmental glomerulosclerosis (FSGS). IgA nephropathy (i.e. Berger's disease). IgM nephropathy. Membranoproliferative glomerulonephritis. Membranous nephropathy. Minimal change disease. Sarcoidosis. Alport's syndrome. Diabetes mellitus (diabetic nephropathy). Drugs (e.g.

Focal segmental glomerulosclerosis

focal segmental glomerular sclerosisFSGSFocal and segmental glomerular lesions
Focal segmental glomerulosclerosis (FSGS) is a cause of nephrotic syndrome in children and adolescents, as well as a leading cause of kidney failure in adults. It is also known as "focal glomerular sclerosis" or "focal nodular glomerulosclerosis." It accounts for about a sixth of the cases of nephrotic syndrome. (Minimal change disease (MCD) is by far the most common cause of nephrotic syndrome in children: MCD and primary FSGS may have a similar cause. ) Depending on the cause it is broadly classified as: There are many other classification schemes also.

Membranous glomerulonephritis

membranous nephropathymembranous nephritisglomerulonephritis, membranous
Membranous glomerulonephritis (MGN) is a slowly progressive disease of the kidney affecting mostly people between ages of 30 and 50 years, usually Caucasian. It is the second most common cause of nephrotic syndrome in adults, with focal segmental glomerulosclerosis (FSGS) recently becoming the most common. Some people may present as nephrotic syndrome with proteinuria, edema with or without kidney failure. Others may not have symptoms and may be picked up on screening or urinalysis as having high amounts of protein loss in the urine.