Renal tuberculosis

And other causes of hypercalcemia (and thus hypercalciuria)

- Immobilization (leading to hypercalcemia and hypercalciuria)

- Milk-alkali syndrome

- Hypervitaminosis D

- Multiple myeloma

Nephrocalcinosis Is connected with conditions that cause hypercalcemia, hyperphosphatemia, and the increased excretion of calcium, phosphate, and/or oxalate in the urine. A high urine pH can lead to Nephrocalcinosis. In conjustion with Nephrocalcinosis, hypercalcemia and hypercalciuria the following can occur:

- Primary hyperparathyroidism: Nephrocalcinosis is one of the most common symptoms of primary hyperparathyroidism.

- Sarcoidosis: Nephrocalcinosis is one of the most common symptoms.

- Vitamin D therapy: This can cause nephrocalcinosis because of Vitamin D therapy becauseit increase the absorption of ingested calcium and bone resorption, resulting in hypercalcemia and hypercalciuria.

The evidence linking vitamin C supplements with an increased rate of kidney stones is inconclusive. The excess dietary intake of vitamin C might increase the risk of calcium oxalate stone formation, in practice this is rarely encountered. The link between vitamin D intake and kidney stones is also tenuous. Excessive vitamin D supplementation may increase the risk of stone formation by increasing the intestinal absorption of calcium; correction of a deficiency does not.

There are no conclusive data demonstrating a cause-and-effect relationship between alcoholic beverage consumption and kidney stones. However, some have theorized that certain behaviors associated with frequent and binge drinking can lead to dehydration, which can, in turn, lead to the development of kidney stones.

The American Urological Association has projected that global warming will lead to an increased incidence of kidney stones in the United States by expanding the "kidney stone belt" of the southern United States.

People with lymphoproliferative/myeloproliferative disorders who were treated with chemotherapy developed symptomatic kidney stones 1.8% of the time in one study.

In ADPKD patients, gradual cyst development and expansion result in kidney enlargement, and during the course of the disease, glomerular filtration rate (GFR) remains normal for decades before kidney function starts to progressively deteriorate, making early prediction of renal outcome difficult. The CRISP study, mentioned in the treatment section above, contributed to build a strong rationale supporting the prognostic value of total kidney volume (TKV) in ADPKD; TKV (evaluated by MRI) increases steadily and a higher rate of kidney enlargement correlated with accelerated decline of GFR, while patient height-adjusted TKV (HtTKV) ≥600 ml/m predicts the development of stage 3 chronic kidney disease within 8 years.

Besides TKV and HtTKV, the estimated glomerular filtration rate (eGFR) has also been tentatively used to predict the progression of ADPKD. After the analysis of CT or MRI scans of 590 patients with ADPKD treated at the Mayo Translational Polycystic Kidney Disease Center, Irazabal and colleagues developed an imaging-based classification system to predict the rate of eGFR decline in patients with ADPKD. In this prognostic method, patients are divided into five subclasses of estimated kidney growth rates according to age-specific HtTKV ranges (1A, 6.0%) as delineated in the CRISP study. The decline in eGFR over the years following initial TKV measurement is significantly different between all five patient subclasses, with those in subclass 1E having the most rapid decline.

Epidemiologically speaking, nephronophthisis, occurs equally in both sexes, and has an estimate 9 in about 8 million rate in individuals. Nephronophthisis is the leading monogenic cause of end-stage renal disease.

It is accepted that kidney transplantation is the preferred treatment for ADPKD patients with end-stage renal disease (ESRD). Among American patients on the kidney transplant waiting list (as of December 2011), 7256 (8.4%) were listed due to cystic kidney disease and of the 16,055 renal transplants performed in 2011, 2057 (12.8%) were done for patients with cystic kidney disease, with 1,189 from deceased donors and 868 from living donors.

Prompt treatment of some causes of azotemia can result in restoration of kidney function; delayed treatment may result in permanent loss of renal function. Treatment may include hemodialysis or peritoneal dialysis, medications to increase cardiac output and increase blood pressure, and the treatment of the condition that caused the azotemia.

Azotemia has three classifications, depending on its causative origin. A BUN/Cr > 20 tends to herald prerenal azotemia (commonly secondary to dehydration but also any other reason perfusion to kidneys is decreased). The BUN-to-creatinine ratio (BUN:Cr) is a useful measure in determining the type of azotemia. A normal BUN:Cr is equal to 15.

The management of this condition can be done via-improvement of any electrolyte imbalance, as well as, hypertension and anemia treatment as the individuals condition warrants.

There are three main mechanisms to cause proteinuria:

- Due to disease in the glomerulus

- Because of increased quantity of proteins in serum (overflow proteinuria)

- Due to low reabsorption at proximal tubule (Fanconi syndrome)

Proteinuria can also be caused by certain biological agents, such as bevacizumab (Avastin) used in cancer treatment. Excessive fluid intake (drinking in excess of 4 litres of water per day) is another cause.

Also leptin administration to normotensive Sprague Dawley rats during pregnancy significantly increases urinary protein excretion.

Proteinuria may be a sign of renal (kidney) damage. Since serum proteins are readily reabsorbed from urine, the presence of excess protein indicates either an insufficiency of absorption or impaired filtration. People with diabetes may have damaged nephrons and develop proteinuria. The most common cause of proteinuria is diabetes, and in any person with proteinuria and diabetes, the cause of the underlying proteinuria should be separated into two categories: diabetic proteinuria versus the field.

With severe proteinuria, general hypoproteinemia can develop which results in

diminished oncotic pressure. Symptoms of diminished oncotic pressure may include ascites, edema and hydrothorax.

Nephrosis is any of various forms of kidney disease (nephropathy). In an old and broad sense of the term, it is any nephropathy, but in current usage the term is usually restricted to a narrower sense of nephropathy without inflammation or neoplasia, in which sense it is distinguished from nephritis, which involves inflammation. It is also defined as any purely degenerative disease of the renal tubules. Nephrosis is characterized by a set of signs called the nephrotic syndrome. Nephrosis can be a primary disorder or can be secondary to another disorder. Nephrotic complications of another disorder can coexist with nephritic complications. In other words, nephrosis and nephritis can be pathophysiologically contradistinguished, but that does not mean that they cannot occur simultaneously.

Types of nephrosis include amyloid nephrosis and osmotic nephrosis.

Proteinuria may be a feature of the following conditions:

- 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. NSAIDs, nicotine, penicillamine, lithium carbonate, gold and other heavy metals, ACE inhibitors, antibiotics, or opiates (especially heroin)

- Fabry's disease

- Infections (e.g. HIV, syphilis, hepatitis, poststreptococcal infection, urinary schistosomiasis)

- Aminoaciduria

- Fanconi syndrome in association with Wilson disease

- Hypertensive nephrosclerosis

- Interstitial nephritis

- Sickle cell disease

- Hemoglobinuria

- Multiple myeloma

- Myoglobinuria

- Organ rejection:

- Ebola virus disease

- Nail patella syndrome

- Familial Mediterranean fever

- HELLP Syndrome

- Systemic lupus erythematosus

- Granulomatosis with polyangiitis

- Rheumatoid arthritis

- Glycogen storage disease type 1

- Goodpasture's syndrome

- Henoch–Schönlein purpura

- A urinary tract infection which has spread to the kidney(s)

- Sjögren's syndrome

- Post-infectious glomerulonephritis

While most cases of horseshoe kidneys are asymptomatic and discovered upon autopsy, the condition may increase the risk for:

- Kidney obstruction – abnormal placement of ureter may lead to obstruction and dilation of the kidney.

- Kidney infections – associated with vesicoureteral reflux.

- Kidney stones – deviant orientation of kidneys combined with slow urine flow and kidney obstruction may lead to kidney stones.

- Kidney cancer – increased risk of renal cancer, especially Wilms' tumor, transitional cell carcinoma, and an occasional case report of carcinoid tumor. Despite increased risk, the overall risk is still relatively low.

The prevalence of horseshoe kidneys in females with Turner Syndrome is about 15%.

It can be associated with trisomy 18.

It can be associated with venous anomalies like left sided IVC 9.

Renal osteodystrophy has been classically described to be the result of hyperparathyroidism secondary to hyperphosphatemia combined with hypocalcemia, both of which are due to decreased excretion of phosphate by the damaged kidney. Low activated vitamin D levels are a result of the damaged kidneys' inability to convert vitamin D into its active form, calcitriol, and result in further hypocalcaemia. High levels of fibroblast growth factor 23 seem now to be the most important cause of decreased calcitriol levels in CKD patients. In CKD the excessive production of parathyroid hormone increases the bone resorption rate and leads to histologic bone signs of secondary hyperparathyroidism. However, in other situations, the initial increase in parathyroid hormone and bone remodeling may be slowed down excessively by a multitude of factors including age, ethnic origin, sex, and treatments such as vitamin D, calcium salts, calcimimetics, steroids, and so forth, leading to low bone turnover or adynamic bone disease. Both high and low bone turnover diseases are currently observed equally in CKD patients treated by dialysis, and all types of renal osteodystrophy are associated with an increased risk of skeletal fractures, reduced quality of life, and poor clinical outcomes.

Renal osteodystrophy is currently defined as an alteration of bone morphology in patients with chronic kidney disease (CKD). It is one measure of the skeletal component of the systemic disorder of chronic kidney disease-mineral and bone disorder (CKD-MBD). The term "renal osteodystrophy" was coined in 1943, 60 years after an association was identified between bone disease and renal failure. The traditional types of renal osteodystrophy have been defined on the basis of turnover and mineralization as follows: mild, slight increase in turnover and normal mineralization; osteitis fibrosa, increased turnover and normal mineralization; osteomalacia, decreased turnover and abnormal mineralization; adynamic, decreased turnover and acellularity; mixed, increased turnover with abnormal mineralization. A Kidney Disease: Improving Global Outcomes report has suggested that bone biopsies in patients with CKD should be characterized by determining bone turnover, mineralization, and volume (TMV system). On the other hand, CKD-MBD is defined as a systemic disorder of mineral and bone metabolism due to CKD manifested by either one or a combination of the following: 1) abnormalities of calcium, phosphorus, PTH, or vitamin D metabolism; 2) abnormalities in bone turnover, mineralization, volume, linear growth, or strength (renal osteodystrophy); and 3) vascular or other soft-tissue calcification.

When originally characterized by Giedion, there was a relatively high mortality rate due to untreated kidney failure (end stage renal disease - ESRD). The remarkable improvements in kidney transplantation have reduced the mortality of Conorenal Syndrome substantially if not eliminated it entirely. Most diagnosis of the disease occurs when children present with kidney failure – usually between the ages of 10 and 14. There are no known cures for the syndrome and management of the symptoms seems to be the typical approach.

Chronic kidney disease–mineral and bone disorder (CKD-MBD) is one of the many complications associated with chronic kidney disease. It represents a systemic disorder of mineral and bone metabolism due to CKD manifested by either one or a combination of the following:

- Abnormalities of calcium, phosphorus (phosphate), parathyroid hormone, or vitamin D metabolism

- Abnormalities in bone turnover, mineralization, volume, linear growth, or strength

- Vascular or other soft-tissue calcification

CKD-MBD explains, at least in part, the high morbidity and mortality of CKD patients, linking kidney and bone disease with cardiovascular complications. It is a matter of discussion whether CKD-MBD may be considered a real syndrome or not.

CKD-MBD broadens the "old" concept of "renal osteodystrophy", which now should be restricted to describing the "bone pathology" associated with CKD. Thus, renal osteodystrophy is currently considered "one" measure of the skeletal component of the systemic disorder of CKD–MBD that is quantifiable by histomorphometry of bone biopsy.

Conorenal syndrome, also called Mainzer-Saldino syndrome or Saldino-Mainzer disease, is a collection of medical conditions that seem to have a common genetic cause.

Based on studies conducted in the United States, the prognosis for individuals with ALECT2 amyloidosis is guarded, particularly because they are elderly and their kidney disease is usually well-advanced at the time of presentation. End-stage renal disease develops in 1 out of 3 patients and has a median renal survival of 62 months. A suggested prognostic tool is to track creatinine levels in ALect2 patients. The attached Figure gives survival plotss for individuals with LECT2 renal amyloidosis and serum creatinine levels less than 2 mg/100 ml versus 2 mg/100 ml or greater than 2 mg/100 ml. The results show that afflicted individuals with lower creatinine levels have a ~four-fold higher survival rate.

Iminoglycinuria is believed to be inherited in an autosomal recessive manner. This means a defective gene responsible for the disorder is located on an autosome, and inheritance requires two copies of the defective gene—one from each parent. Parents of an individual with an autosomal recessive disorder both carry one copy of the defective gene, but usually do not experience any signs or symptoms of the disorder.

A non-inherited cause of excess urinary excretion of proline and glycine, similar to that found in iminoglycinuria, is quite common to newborn infants younger than 6 months. Sometimes referred to as neonatal iminoglycinuria, it is due to underdevelopment of high-affinity transport mechanisms within the renal circuit, specifically PAT2, SIT1 and SLC6A18. The condition corrects itself with age. In cases where this persists beyond childhood, however, inherited hyperglycinuria or iminoglycinuria may be suspected.

The frequency is unknown, but the disease is considered to be very rare.

This is much more common, but is not usually of any major health consequence, as long as the other kidney is healthy.

It may be associated with an increased incidence of Müllerian duct abnormalities, which are abnormalities of the development of the female reproductive tract and can be a cause of infertility, blocked menstrual flow (hematocolpos), increased need for Caesarean sections, or other problems. Herlyn-Werner-Wunderlich syndrome is one such syndrome in which unilaterial renal agenesis is combined with a blind hemivagina and uterus didelphys. Up to 40% of women with a urogenital tract anomaly also have an associated renal tract anomaly.

Adults with unilateral renal agenesis have considerably higher chances of hypertension (high blood pressure). People with this condition are advised to approach contact sports with caution.

The odds of a person being born with unilateral renal agenesis are approximately 1 in 750.

In patients with this condition, the central portion of the kidney may be found just inferior to the inferior mesenteric artery because the normal embryologic ascent of the kidneys is arrested by its presence in people with central fusion of the kidneys. Horseshoe kidney is often asymptomatic, though persons affected by this condition may experience nausea, abdominal discomfort, kidney stones and urinary tract infections at greater frequency than those without renal fusion. There is currently no treatment for renal fusion other than symptomatic treatment.

Imaging Findings -

The 2 kidneys on opposite sides of the body with the lower poles fused in midline. Midline or symmetrical fusion (90% of cases).

May be missed on US, therefore pay careful attention to identification of lower poles of kidneys.

Renal long axis medially orientated,

Lower poles with curved configuration, elongation and poorly defined

Isthmus crosses midline anterior to spine and great vessels.

US for diagnosis in utero

IVP followed by CT or scintigraphy for pre-operative assessment

Variant arterial supply -

Bilateral renal arteries,

Inferior mesenteric Artery,

Arteries arising from aorta or common iliac, internal iliac, external iliac or inferior mesenteric arteries.

The lower poles of these kidneys fuse in the midline anterior to the aorta and spine. The isthmus is usually located at L4/5 level between the aorta and IMA.

Nuclear medicine (DMSA) scan confirms horseshoe kidney with fusion of both renal lower poles.

It is well-known that as kidney function declines, there is a progressive deterioration in mineral homeostasis, with a disruption of normal serum and tissue concentrations of phosphorus and calcium, and changes in circulating levels of hormones. These include parathyroid hormone (PTH), 25-hydroxyvitamin D (25(OH) vitamin D; calcidiol), 1,25-dihydroxyvitamin D (1,25(OH)2 vitamin D; calcitriol), and other vitamin D metabolites, fibroblast growth factor 23 (FGF-23), and growth hormone. Beginning in CKD stage 3, the ability of the kidneys to appropriately excrete a phosphate load is diminished, leading to hyperphosphatemia, elevated PTH (secondary hyperparathyroidism), and decreased 1,25(OH)2 vitamin D with associated elevations in the levels of FGF-23. The conversion of 25(OH) vitamin D to 1,25(OH)2 vitamin D is impaired, reducing intestinal calcium absorption and increasing PTH. The kidney fails to respond adequately to PTH, which normally promotes phosphaturia and calcium reabsorption, or to FGF-23, which also enhances phosphate excretion. In addition, there is evidence at the tissue level of a downregulation of vitamin D receptor and of resistance to the actions of PTH. Therapy is generally focused on correcting biochemical and hormonal abnormalities in an effort to limit their consequences.

The mineral and endocrine functions disrupted in CKD are critically important in the regulation of both initial bone formation during growth (bone modeling) and bone structure and function during adulthood (bone remodeling). As a result, bone abnormalities are found almost universally in patients with CKD requiring dialysis (stage 5D), and in the majority of patients with CKD stages 3–5. More recently, there has been an increasing concern of extraskeletal calcification that may result from the deranged mineral and bone metabolism of CKD and from the therapies used to correct these abnormalities.

Numerous cohort studies have shown associations between disorders of mineral metabolism and fractures, cardiovascular disease, and mortality. These observational studies have broadened the focus of CKD-related mineral and bone disorders (MBDs) to include cardiovascular disease (which is the leading cause of death in patients at all stages of CKD). All three of these processes (abnormal mineral metabolism, abnormal bone, and extraskeletal calcification) are closely interrelated and together make a major contribution to the morbidity and mortality of patients with CKD. The traditional definition of renal osteodystrophy did not accurately encompass this more diverse clinical spectrum, based on serum biomarkers, noninvasive imaging, and bone abnormalities. The absence of a generally accepted definition and diagnosis of renal osteodystrophy prompted Kidney Disease: Improving Global Outcomes (KDIGO)] to sponsor a controversies conference, entitled "Definition, Evaluation, and Classification of Renal Osteodystrophy", in 2005. The principal conclusion was that the term "CKD–Mineral and Bone Disorder (CKD–MBD)" should now be used to describe the "broader clinical syndrome encompassing mineral, bone, and calcific cardiovascular abnormalities that develop as a complication of CKD".