Nephrotic syndrome (NS) is one of the clinical manifestations of glomerulonephritis (GN) are marked with anasarka edema, massive proteinuria ≥ 3.5 g / dl, hypercholesterolemia and lipiduria. At the beginning of the process or the mild NS stage, to make the diagnosis, not all symptoms must be found. Massive proteinuria is a typical sign of NS, but in severe NS accompanied low serum albumin concentration, excretion of protein in urine was also reduced.
Proteinuria also contributes to various complications that occur in the NS. Not only Proteinuria,hypoalbuminemia, hiperlipidemia and lipiduria also found in NS. Nitrogen balance diorders, hypercoaguloability, disturbances of calcium and bone metabolism, and thyroid hormones are often found in NS. Generally, NS with normal renal function can heal itself and showed a good response to steroid therapy. However, for some cases develop into end stage renal disease or develop inti chronic.
Nephrotic syndrome can be caused by primary and secondary Glomerulonephritis.
A. Primary Glomerulonephritis
- GN with minimal lessions
- Glomerulosclerotic focal
- Membranous Glomerulonephritis
- GN membranoproliferatif
- Other proliferative
B. Secondary Glomerulonephritis
- HIV, Hepatitis B and C virus
- Syphilis, Malaria
- TBC, Leprosy
- Multiple Myeloma
- Renal Carcinoma
3. Connective Tissue Disease:
- Rhematoid Arthritis
- Mixed Cinnective Tissue Disease
4. Drugs and Toxins:
- Gold Preparations
- Diabetes Mellitus
- Vesikoureter reflux
Primary or idiopathic Glomerulonephritis is the most frequent cause of NS. in Primary GN, histopathological abnormality was found. Due to secondary causes such as infections that are often encountered in post infectious GN Stretococcus or Hepatitis B virus infection, caused by medications such as non steroidal anti-inflammatory drugs or preparations of organic gold, and caused by systemic disease.
Proteinuria caused by increased capillary permeability to proteins due to glomerulus damage. Normally, Glomerular basement membrane (GBM) has a barrier mechanism to prevent leakage of protein.
The first barrier mechanism based on moleculear size (size barrier) and the second based on electrical charge. In the NS, two mechanism are invloved disrupted. Besides the configuration of protein molecules also determine wether the protein passes through the GBM. Proteinuria is divided into selective and non-selective based on size of protein molecules that come out through urine.
Selective proteinuria outif a protein consisits of small molecules such as albumin, while non-selective when the protein comes out such a large molecule composed of immunoglobulin. selectivity of proteinuria determined by GBM structural integrity. In the NS which caused by GN Minimal Lessions, found selective proteinuria.
Electron microscope examination showed fusion of foot processor glomerular visceral epithelial cells and the released of cells from GBM structure. In Glomerulosclerotic Focal, GBM increased permeability caused by a factor involved in the circulation. These factors lead to glomerular visceral epithelial cells regardless of GBM that permeability increases. In Glomerulonephritis Membranous, GBM structural are damage caused by immune complex deposition in the sub-epithelium.
Plasma Albumin concetration determined by protein intake, Liver albumin synthesis, and loss of protein through urine. Hypoalbuminemia is caused by masive proteinuria due to reduced plasma oncotic presure. To maintain plasma oncotic pressure, the liver increases production of albumin. Improvement of liver albumin synthesis was not succesfully to block the emergence hypoalbuminemia. High protein diet can improve liver albumin synthesis, but it may encourage increased excretion of albumin in the urine. Hypoalbuminemia may also occur due to increased reabsorption and catabolism of albumin by the proximal tubule.
Edema can be explained by theory of UNDERFILL and OVERFILL.
- Underfill theory explains that hypoalbuminemia is a factor of edema of NS. Hypoalbuminemia caused a decrease in plasma oncotic pressure so that fluid shifts from intravascular to the network interstitium and edema. Consequent of Oncotic pressure drop due to plasma and plasma fluid shift occurs hypovolemia and to compnsate by increasing renal sodium and water retention. These compensatory mechanisms will improve intravascularvolume but will also excerbates occurence of edema increasingly hypoalbuminemia so continues.
- Overfill theory explains that the retention of sodium as a primary renal defect. retention of Sodium by the kidneys causes increased extracelluler fluid causing edema. Decrease of GFR (glomerulus filtrate rate) due to kidney damage would increase the occurence of sodium retention and edema. Both mechanism found together in patients with NS.
1. Nitrogen balance.
Massive proteinuria in the NS will cause a negative nitrogen balance. Decreased muscle mass is found but these symptoms are often found covered with new symptoms and edema anasarka looked after the edema disappeared. Loss of muscle mass by 10-20% of body mass (lean body mass) are not rare in NS.
2. Hyperlipidemia and Lipiduria.
Hyperlipidemia is a condition that often accompanies SN. Cholesterol levels generally increased, while triglyceride levels vary from normal to slightly rising. Increased cholesterol levels caused by increasing LDL (low density lipoprotein), the major lipoprotein carrier of cholesterol. Trigliserid high levels are associated with increased VLDL (very low density lipoprotein). Also found increased IDL (intermediate density lipoproteins) and lipoprotein (Lp)a, while HDL (high density lipoprotein) cholesterol tends to be normal or low.
Mechanism of hyperlipidemia in the NS associated with elevated lipid and lipoprotein synthesis and decreased catabolism of the liver. Originally thought to hyperlipidemia is the result of non-specific stimulation of protein synthesis by the liver. Therefore, no correlation with protein synthesis concluded that hyperlipidemia hyperlipidemia indirectly caused by hipoalbunemia. Hyperlipidemia can be found in the NS with near-normal albumin levels and vice versa in patients with hypoalbuminemia may be a normal cholesterol level.
High levels of LDL in the NS due to increased synthesis of heart without interruption catabolism. Improved synthesis and disruption of liver VLDL and IDL conversion into LDL causes high levels of VLDL in the NS. The reduced activity of the enzyme LPL (lipoprotein lipase) are thought to cause reduced VLDL catabolism in the NS. Increased lipoprotein synthesis of the liver caused by pressure or viscosity of plasma. Decrease in HDL cholesterol levels in NS allegedly due to reduced enzyme activity HUW (colesterol acyltransferase lecithin) that function catalyzing the formation of HDL. This enzyme also serves to transport cholesterol and circulation to the liver for catabolism.
Decrease in the enzyme activity associated with hypoalbuminemia who allegedly occurred in NS. Lipiduria often found in the SN and is characterized by accumulation of lipids in the cell debris and casts, such as oval fat bodies (oval fat bodies) and fatty casts. Lipiduria more associated with proteinuria than with hyperlipidemia.
Thromboembolic complications are often found in the NS due to increased intravascular coagulation. In the NS occurred due to the tendency GNMN renal vein thrombosis is quite high while the NS on GNMP GN Minimal Lessions and small frequency. Pulmonary embolism and deep venous thrombosis (deep vein thrombosis) are often seen in this NS. Antitrombin caused by loss of (AT) III, protein S, C and plasminogen activating factor in the urine and increased factor V, VII, VIII, X, platelets, fibrinogen, increased platelet aggregation, changes in endothelial cell function and the decrease zimogen factor (factor IX, XI).
4. Calcium and Bone Metabolism
Vitamin D is an important element in calcium and bone metabolism in humans. Vitamin D which banned will be excreted through urine protein causing a decrease in plasma levels. Levels of 25 (OH) D and 12.5 (OH2) D also decreased plasma levels of vitamin D, while free is not susceptible to interference. Therefore, kidney function is generally normal in the NS osteomalasia or uncontrolled hyperparathyroidism is rarely encountered.
NS also happen to lose on thyroid hormone binding protein (thyroid binding protein) through urine and decreased levels of plasma thyroxine. And free thyroxine stimulating hormone, thyroxine (thyroxine stimulating hormone) remained clinically normal so do not cause interference.
Before the era of antibiotics, infection is often the cause of death in the NS, especially by organism (encapsulated organism). Infections caused by defects in humoral immunity, cellular, and disruption of the complement system. Decrease in IgG, IgA, and gamma globulin are often found in patients with SN , therefore decreased synthesis or increased catabolism and increased in numbers is wasted through urine.
The number of T cells in the circulation is reduced which describes cellular immunity disorders. This is associated with the release of transferrin and zinc are required by T cells to function normally.
6. Impaired Renal Function
NS patients have the potential to occur with acute renal failure through various mechanisms. Decrease in plasma volume or sepsis often causes acute tubular necrosis. Another mechanism which is expected to cause acute renal failure intrarenal edema causing compression of the renal tubules. Nephrotic syndrome can be progressive and developed into PGTA.
Proteinuria is a risk factor determinants of the progression of SN. Progression of glomerular damage, glomerulosklerosis developments, and damage associated with proteinuria tubulointerstisium. Hyperlipidemia are also associated with the occurrence mechanism and fibrosis glomerulosklerosis tubulointerstisium on SN, although the role of the progression of the disease is not known with certainty.
7. Other complications
Protein-calorie malnutrition can occur in adults, especially if accompanied NS massive proteinuria, less oral intake, and high catabolism process. Possible toxic effects of drugs that are bound to increase due to hypoalbuminemia causing proteinakan OTC levels in plasma higher. Hypertension is not uncommon as a complication of NS mainly associated with sodium and water retention.
E. NS DIAGNOSE
NS diagnosis is made based on clinical and laboratory examination of proteinuri massive (> 3.5 g / dl), hipoalbuminemi (<3 g / dl), edema, hiperlipidemi, lipiduri and hypercoagulabilityvenografi required to diagnose venous thrombosis which can occur due to hypercoagulability. In NS primer to determine the type of renal histopathologic abnormalities that determine the prognosis and response to therapy, renal biopsy is necessary.
In patients can be diagnosed with NS because:
1. From physical examination found the existence of edema anasarka especially in the second leg, both legs and abdomen.
2. From examination laboratorim can be found:
- Lipd: elevated triglycerides, total cholesterol, and LDL cholesterol
- Urine: proteinuria found the existence of twoThe radiological examination did not reveal any abnormality.
The treatment of NS include specific therapies for disorders or diseases causing kidney foundation (at secondary NS), reduce or eliminate proteinuria, repairing and preventing and overcoming hipoalbuminemi complication. Minimal lesions nephropathy and membranous nephropathy are two disorders that respond well to steroid therapy. Other researchers found that the focal segmental glomerulosklerosis up 40% of patients responded well to steroids with complete remission.
Schieppati found that in most patients with idiopathic membranous nephropathy, symptomatic therapy with better kidney function for a long time and can heal spontaneously. Therefore they do not support the use of glucocorticoids and immunosuppressive in this type of nephropathy. Use of corticosteroid regimens in a variety of NS, including prednisone 125 mg once every two days during two months later reduced the dose gradually and stopped after 1-2 months if relapse, therapy may be repeated. Other regimens in adults is prednisone / corticosteroid 1 to 1.5 mg / kg body weight / day for 4 weeks followed by 1 mg / kg of body weight one day intervals for 4 weeks.
Up to 90% of patients remission if therapy will be continued until 20-24 weeks, but 50% of patients will experience a relapse after corticosteroid is stopped. Hopper uses doses of 100 mg/48 hours. If there is no progress in 2-4 weeks, the dose was increased to 200 mg per 48 hours and maintained until proteinuri down to 2 grams or less per 24 hours, or until the therapy is considered to no avail. In children given prednisone 60 mg/m2 body surface area or 2 mg / kg body weight / day for 4 weeks, followed by 40 mg/m2 body surface area every two days during four weeks clinical.
Respondof corticosteroids can be divided into:
a. Complete remission
- proteinuri minimal (<200 mg/24 hours) • Serum albumin> 3 g / dl
- serum cholesterol <300 mg / dl
- Current diuresis and edema disappeared
b. Partial Remission
- proteinuri <3.5 g / day • Serum albumin> 2.5 g / dl
- serum cholesterol <350 mg / dl
- diuresis substandard and still edema
- clinical and laboratory showed no change or improvement after four months of treatment with corticosteroids.
Corticosteroids provide a complete remission in 67% cases of minimal lesion nephropathy NS, complete or partial remission in 50% NS membranous nephropathy and 20% -40% in focal segmental glomerulosklerosis. Please note the side effects of long-term corticosteroid use include aseptic necrosis, cataracts, osteoporosis, hypertension, diabetes mellitus.
In patients unresponsive to corticosteroids, to reduce proteinuria use symptomatic therapy with angiotensin converting enzyme inhibitor (ACEI), such a low dose of captopril or enalapril, and the dose increased after 2 weeks or non-steroidal antiinflammatory drugs (NSAIDs), such as indomethacin 3 × 50mg. Angiotensin converting enzyme inhibitors reduce glomerular protein ultrafiltration by reducing pressure and improving intrakapiler glomerulus glomerular size selective barrier.
Antiproteinuria effects of this drug lasts longer (approximately two months after the drug was stopped). Angiotensin receptor blockers (ARBs) was also able to improve proteinuri because it inhibits inflammation and fibrosis interstisium, inhibiting the release of cytokines, growth factors, adhesion molecules due to the work of local angiotensin II in the kidneys. Combination ACEI and ARB was reported to give greater antiproteinuria effect on primary glomerulonephritis compared with ACEI or ARB use only.
Non-steroidal antiinflammatory drugs can be used in patients with membranous nephropathy and focal segmental glomerulosklerosis to reduce prostaglandin synthesis. This causes renal vasoconstriction, decreased glomerular capillary pressure, filtration surface area and reduce proteinuria up to 75%. Besides NSAIDs can reduce the levels of fibrinogen, fibrin-related antigenic and prevent platelet aggregation. However, please note that NSAIDs cause a progressive decline in renal function in some patients.
This medicine should not be given if the creatinine clearance <50 ml / min. In patients who frequently relapse with corticosteroids or corticosteroid resistant to other therapies can be used with cyclophosphamide or chlorambucil. Cyclophosphamide gives a longer remission than corticosteroids (75% over two years) with a dose of 2-3 mg / kg bw / day for 8 weeks. Side effects of cyclophosphamide is bone marrow depression, infection, alopecia, hemorrhagic cystitis and infertility if given more than six months.
Chlorambucil given at a dose of 0.1 to 0.2 mg / kg bb. / day for 8 weeks. Side effects of chlorambucil is azoospermia and agranulocytosis. Ponticelli and colleagues found that in idiopathic membranous nephropathy, a combination of methylprednisolone and chlorambucil for six months earlier to induce remission and maintain renal function as compared with methylprednisolone alone, but this difference diminished with time (in four years this difference was not significant anymore) . Regimen used was methylprednisolone 1 g / day intravenously for 3 days, then 0.4 mg / kg / day for 27 days followed by peroral chlorambucil 0.2 mg / kg / day one month ago seling. Another alternative therapy membranous nephropathy is cyclophosphamide 2 mg / kg / day plus 30 mg of corticosteroid every 2 days for several months (maximum 6 months).
Levamisol a antihelmintic, can be used for minimal lesions nephropathy NS therapy in children with a dose of 2.5 mg / kg body weight every two days at least 112 days. A rare side effect is netropeni, thrombocytopenia and skin rash. Cyclosporine A can be attempted in patients who relapse after being given cyclophosphamide or to prolong remission after administration of corticosteroids. Dose of 3-5 mg / kg / day for six months to one year (after 6 months of reduced doses of 25% every two months). Cyclosporin A can also be used in combination with a corticosteroid in the case of a failed SN in combination with other therapies. Side effects of this drug is hiperplasi gingival, hypertrichosis, hiperurisemi, hypertension and nefrotoksis.
Other therapies that have not proven their effectiveness is azatioprin 2 to 2.5 mg / kg / day for 12 months. In the case of NS that were resistant to steroid and drug imunospresan, this time can be given a new immunosuppressive mycophenolate mofetil (MMF), which has the effect of inhibiting the proliferation of B lymphocytes and T lymphocytes, inhibits antibody production of B cells and adhesion molecule expression, inhibit cell proliferation vascular smooth muscle.
Resistance to this diuretic is multifactorial. Hipoalbuminemi Allegedly reduce drug transport to work, while binding by the urine protein is not the main mechanism for this resistance. In such patients can be given intravenous salt-poor human albumin. This therapy is said to increase plasma volume, increased glomerular filtration rate, urine flow and sodium excretion. However, albumin infusion is still doubt its effectiveness as quickly excreted through the urine albumin, other than that can increase blood pressure and even pulmonary edema in patients hipervolemi. Hiperlipidemia in the long term increase the risk of early atherosclerosis.
To overcome the barrier can be used hiperlipidemia hidroxymethyl glutaryl co-enzyme A (HMG Co-A) reductase that effectively lower plasma cholesterol. These drugs are said to be most effective with minimal side effects. Gemfibrozil, bezafibrat, klofibrat significantly lower triglyceride levels and slightly lower cholesterol levels. Klofibrat can be toxic at normal levels due to increased levels of free klofibrat cause muscle damage and acute renal failure. Probukol reduce total cholesterol and LDL cholesterol, but minimal effect on triglycerides. Nicotinic acid (niacin) can lower cholesterol and more effective when combined with gemfibrozil.
Kolestipol Kolestiramin and effectively lower total cholesterol and LDL cholesterol, but this drug is not recommended because of their effect on intestinal absorption of vitamin D in vitamin D deficiency is exacerbated in the NS. To prevent thromboembolic complications of hypercoagulability that occurs in approximately 20% of cases of NS (most frequently in membranous nephropathy), used dipiridamol (3 x 75 mg) or aspirin (100 mg / day) as an anti-platelet aggregation and deposition of fibrin / thrombus. Besides these drugs can reduce significantly decreased kidney function and the occurrence of end stage renal failure. This therapy is given for patients experiencing nephrotic proteinuri, albumin <2 g / dl, or both. In case of thromboembolism, heparin should be given intravenous / infusion for 5 days, followed by oral warfarin administration until three months or after a healing SN. Giving heparin with activated partial thromboplastin time monitoring (aPTT) 1.5 to 2.5 times control, whereas the effect of warfarin was evaluated by prothrombin time (PT) is usually expressed as International Normalized Ratio (INR) 2-3 times normal.
In the event of complications of bacterial infections (pneumococcal pneumonia or peritonitis) are given the appropriate antibiotics and can be accompanied with intravenous immunoglobulin G administration. For pneumococcal vaccine used to prevent infection. The use of immunosuppressive virus infections cause problems such as measles and herpes. Another complication that can occur include hypertension, hypovolaemic shock, acute renal failure, chronic renal failure (after 5-15 years). Handling similar to handling this situation in general. In case of chronic renal failure, in addition to hemodialysis, kidney transplantation can be performed. Dantal et al found in patients with focal segmental glomerulosklerosis who underwent kidney transplants, 15% -55% NS will happen again. Recurrence may be caused by plasma factors (circulating factors) or factors that increase glomerular permeability.
Imunoadsorption plasma protein A decrease urine protein excretion in patients with focal segmental NS because glomerulosklerosis, membranous nephropathy and secondary NS because of diabetes mellitus. Imunoadsorpsi suspected release of plasma factors that alter hemodynamic or factors that increase glomerular permeability.