Nephrotic Syndrome

from Wikipedia, the free encyclopedia
Classification according to ICD-10
N04.9 Nephrotic Syndrome
ICD-10 online (WHO version 2019)

The nephrotic syndrome is a collective medical term for several symptoms that occur in various diseases of the glomerulum (in the kidney corpuscle). In general, nephrotic syndrome is differentiated from nephritic syndrome , as is nephrosis from nephritis and nephropathy from nephrosclerosis . Renal insufficiency without kidney disease must also be considered; these are the extrarenal kidney syndromes according to Wilhelm Nonnenbruch .

The nephrotic syndrome is characterized by four main symptoms:

So-called large proteinuria is when the amount of protein in the urine is more than 3–3.5 g per 24 hours, in children it is more than 1 g per m²  body surface area in 24 hours. The albumin in the serum is reduced to below 2.5 g / dl.

Pathogenesis

The nephrotic syndrome results from the increased permeability of the glomerulum for proteins (proteins), protein molecules> 60 kDa are filtered. Albumin , which has a mass of approx. 65 kD and makes up approx. 60% of the protein dissolved in the blood plasma, has the largest share in the protein losses . There is hypoproteinemia with hypoalbuminemia and proteinuria due to the increased renal protein excretion . A daily protein excretion of more than 4 g indicates considerable damage to the filter function of the kidneys. Less than 0.05 g protein per day is normally excreted via the kidneys.

When the albumin content in the blood drops, hypoalbuminemic edema also occurs . These arise due to a decreased colloid osmotic pressure in the vessels due to the loss of protein . There is a loss of fluid from the blood plasma into the tissue surrounding the vessels . The edema is more pronounced the lower the protein or albumin content in the blood. Pleural effusion can also occur as a result of the hypoalbuminemia .

The body tries to counteract the loss of protein by replacing this loss as quickly as possible. There is an increased production of lipoproteins by the liver , which together with the loss of the enzyme lipoprotein lipase, which occurs in the context of proteinuria, leads to hyperlipidemia . In addition, due to the size and nature of the particles, the loss of cholesterol and triglyceride-transporting lipoproteins is relatively lower, so that the ratio of blood lipids to one another changes in an unfavorable manner ( dyslipidemia ).

The increased loss of fluid from the vessels into the tissue leads to hypovolemia . This lack of fluid now stimulates the body's so-called RAAS ( renin-angiotensin-aldosterone system ). This system is intended to compensate for the loss of fluid by narrowing the blood vessels and thus increasing blood pressure . In addition, the kidneys retain more water and sodium in the body. However, it is precisely this mechanism that leads to an increase in the glomerular filtration rate (GFR) via increased blood pressure and thus to further protein loss (positive feedback).

causes

The nephrotic syndrome does not in itself represent a disease, but rather a complex of symptoms of the same type, behind which various diseases are hidden. The most common causes of nephrotic syndrome:

Less common causes:

Symptoms

Child with massive edema (anasarca) due to malaria-related renal failure

In addition to the key symptoms of the nephrotic syndrome already mentioned, the patient also has the symptoms of the underlying disease. As the disease progresses, there is an increased tendency to become infected, as the loss of protein means that antibodies , especially IgG , are also lost. Furthermore, there is a loss of antithrombin III . AT III is a component of the blood plasma and has a strong inhibitory effect on blood clotting . If AT III is lost, there is increased coagulation of the blood in the vessels and thus thrombosis , especially of the renal veins . Persistent damage to the kidneys shows signs of renal insufficiency in advanced stages, such as flank pain, bloody urine , reduced urine output .

Other possible consequences include anemia , hypothyroidism , vitamin D deficiency, hypovolemic shock, and intussusception .

therapy

  • The treatment of the underlying disease or the elimination of toxic causes that trigger the nephrotic syndrome are at the forefront of therapy .
  • Low-salt diet
  • Adequate protein intake (1–2 g / kg body weight per day) from natural, low-fat sources with the aim of a positive nitrogen balance . Some sources recommend a protein restriction.
  • Restriction of fluid intake and diuretics (mainly potassium-sparing diuretics and thiazide diuretics , later possibly loop diuretics )
  • Treatment of bacterial infections and their prophylaxis (recommended pneumococcal - vaccination ); there is little point in giving immunoglobulins : they quickly suffer the same fate as albumins.
  • Lowering cholesterol levels with CSE inhibitors
  • Therapy of high blood pressure , depending on the degree of kidney function. The drug of choice is an ACE inhibitor .
  • standardized prednisolone therapy as a causal treatment (usually 1 mg / kg per day), because it affects the protein permeability of the basement membrane.
  • If the AT III drops to below 70%, marcoumarization is indicated.

Classification

  • Type I: Complete healing after an attack
  • Type II: tendency to relapse with complete remission
  • Type III: Permanent impaired kidney function despite partial remission
  • Type IV: Rapid progression with poor prognosis

history

In ancient Greece, the accumulation of body water was regarded as a uniform clinical picture ( dropsy , hydropisis). In 1827 Richard Bright recognized that some of the patients with dropsy also suffered from increased urine protein excretion and from abnormal kidney changes. In 1914 Franz Volhard and Theodor Fahr differentiated between degenerative (nephrosis), inflammatory (nephritis) and arteriosclerotic ( sclerosis ) kidney diseases. In 1963 George Schreiner examined the urinary protein excretion of 186 patients with the clinical signs of a nephrotic syndrome. The lowest amount of protein he observed was 3.5 g per day. In 1983, Ginsberg suggested that instead of collecting urine over 24 hours, the ratio between protein and creatinine should be determined in a urine sample that was left spontaneously. Since the excretion of creatinine in the urine happens to be about 1 g per day, he suggested a protein / creatinine ratio in urine of 3.5 g protein / g creatinine as a limit value for nephrotic syndrome . Recently, the excretion of albumin in the urine has been increasingly determined, which should provide more precise values ​​than the determination of total protein . As the lower limit of the nephrotic syndrome, Stoycheff suggested an albumin / creatinine ratio in urine of 2.2 g albumin per g creatinine.

See also

literature

Individual evidence

  1. ^ Roche Lexicon Medicine , 5th edition, Urban & Fischer , Munich, Jena 2003, ISBN 978-3-437-15156-9 , S 1303-1305.
  2. ^ Wilhelm Nonnenbruch : The double-sided kidney diseases , Ferdinand Enke Verlag , Stuttgart 1949, pp. 180−192.
  3. ↑ a b Gerd Herold: Internal medicine: a lecture-oriented presentation , 2012. Edition, Herold, Cologne 2012, ISBN 978-3-9814660-1-0 .
  4. ↑ Berthold Jany, Tobias Welte: Pleural effusion in adults - causes, diagnosis and therapy. In: Deutsches Ärzteblatt , Volume 116, Issue 21/2019, May 24, 2019, pp. 377–386, here: pp. 379 and 381 f.
  5. ^ Society for Pediatric Nephrology (GPN): AWMF guideline (S2e): Idiopathic nephrotic syndrome in childhood: diagnosis and therapy. In: Working Group of Scientific Medical Associations. Accessed on October 28, 2018 .
  6. ^ Article "Hypoalbuminemia Medication" in Medscape
  7. ↑ Article "Nephrotic Syndrome Treatment & Management in Medscape
  8. ^ Article "Nephrotic Syndrome: Lifestyle and home remedies" in mayoclinic.com
  9. ^ G. Eknoyan: A history of edema and its management . In: Kidney International . Supplement . 59, June 1997, ISSN  0098-6577 , pp. S118-126. PMID 9185118 .
  10. ↑ Bright's disease in the English language Wikipedia
  11. ↑ JS Cameron Bright's Disease Today: The Pathogenesis and Treatment of glomerulonephritis - I . In: British Medical Journal . 4, No. 5832, October 14, 1972, ISSN  0007-1447 , pp. 87-90. PMC 1786202 (free full text).
  12. ^ A. Heidland, et al .: Franz Volhard and Theodor Fahr: achievements and controversies in their research in renal disease and hypertension . In: Journal of Human Hypertension . 15, No. 1, January 2001, ISSN  0950-9240 , pp. 5-16. PMID 11223997 .
  13. ↑ MB Strauss, LG World. Diseases of the Kidney. (ed 2). MA Boston: Little Brown; 1963.
  14. ↑ JM Ginsberg, et al .: Use of single voided urine samples to estimate quantitative proteinuria . In: The New England Journal of Medicine . 309, No. 25, December 22, 1983, ISSN  0028-4793 , pp. 1543-1546. doi : 10.1056 / NEJM198312223092503 . PMID 6656849 .
  15. ^ W. Greg Miller, et al .: Current issues in measurement and reporting of urinary albumin excretion . In: Clinical Chemistry . 55, No. 1, January 2009, ISSN  1530-8561 , pp. 24-38. doi : 10.1373 / clinchem.2008.106567 . PMID 19028824 .
  16. ↑ Nicholas Stoycheff, et al .: Nephrotic syndrome in diabetic kidney disease: an evaluation and update of the definition . In: American Journal of Kidney Diseases . 54, No. 5, November 2009, ISSN  1523-6838 , pp. 840-849. doi : 10.1053 / j.ajkd.2009.04.016 . PMID 19556043 .