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No treatment modality has been unequivocally demonstrated to reduce the complications of alkaptonuria. Main treatment attempts have focused on preventing ochronosis through the reduction of accumulating homogentisic acid. Such commonly recommended treatments include large doses of ascorbic acid (vitamin C) or dietary restriction of amino acids phenylalanine and tyrosine. However, vitamin C treatment has not shown to be effective, and protein restriction (which can be difficult to adhere to) has not shown to be effective in clinical studies.
Several recent studies have suggested that the herbicide nitisinone may be effective in the treatment of alkaptonuria. Nitisinone inhibits the enzyme, 4-hydroxyphenylpyruvate dioxygenase, responsible for converting tyrosine to homogentisic acid, thereby blocking the production and accumulation of HGA. Nitisinone has been used for some time at much higher doses in the treatment of type I tyrosinemia. Nitisinone treatment has been shown to cause a larger than 95% reduction in plasma and urinary HGA. The main drawback is accumulation of tyrosine, the long-term risks of which are unknown; there is a particular concern about damage to the cornea of the eye. Long-term use would require frequent monitoring for complications.
No cures for lysosomal storage diseases are known, and treatment is mostly symptomatic, although bone marrow transplantation and enzyme replacement therapy (ERT) have been tried with some success. ERT can minimize symptoms and prevent permanent damage to the body. In addition, umbilical cord blood transplantation is being performed at specialized centers for a number of these diseases. In addition, substrate reduction therapy, a method used to decrease the production of storage material, is currently being evaluated for some of these diseases. Furthermore, chaperone therapy, a technique used to stabilize the defective enzymes produced by patients, is being examined for certain of these disorders. The experimental technique of gene therapy may offer cures in the future.
Ambroxol has recently been shown to increase activity of the lysosomal enzyme glucocerebrosidase, so it may be a useful therapeutic agent for both Gaucher disease and Parkinson's disease. Ambroxol triggers the secretion of lysosomes from cells by inducing a pH-dependent calcium release from acidic calcium stores. Hence, relieving the cell from accumulating degradation products is a proposed mechanism by which this drug may help.
Some children with LAL-D have had an experimental therapy called hematopoietic stem cell transplantation (HSCT), also known as bone marrow transplant, to try to prevent the disease from getting worse. Data are sparse but there is a known high risk of serious complications including death, graft-versus-host disease.
LAL deficiency can be treated with sebelipase alfa is a recombinant form of LAL that was approved in 2015 in the US and EU. The disease of LAL affects < 0.2 in 10,000 people in the EU. According to an estimate by a Barclays analyst, the drug will be priced at about US $375,000 per year.
It is administered once a week via intraveneous infusion in people with rapidly progressing disease in the first six months of life. In people with less aggressive disease, it is given every other week.
Before the drug was approved, treatment of infants was mainly focused on reducing specific complications and was provided in specialized centers. Specific interventions for infants included changing from breast or normal bottle formula to a specialized low fat formula, intravenous feeding, antibiotics for infections, and steroid replacement therapy because of concerns about adrenal function.
Statins were used in people with LAL-D prior to the approval of sebelipase alfa; they helped control cholesterol but did not appear to slow liver damage; liver transplantation was necessary in most patients.
Treatment consists of oral bicarbonate supplementation. However, this will increase urinary bicarbonate wasting and may well promote a bicarbonate . The amount of bicarbonate given may have to be very large to stay ahead of the urinary losses. Correction with oral bicarbonate may exacerbate urinary potassium losses and precipitate hypokalemia. As with dRTA, reversal of the chronic acidosis should reverse bone demineralization.
Thiazide diuretics can also be used as treatment by making use of contraction alkalosis caused by them.
As of today, no agreed-upon treatment of Dent's disease is known and no therapy has been formally accepted. Most treatment measures are supportive in nature:
- Thiazide diuretics (i.e. hydrochlorothiazide) have been used with success in reducing the calcium output in urine, but they are also known to cause hypokalemia.
- In rats with diabetes insipidus, thiazide diuretics inhibit the NaCl cotransporter in the renal distal convoluted tubule, leading indirectly to less water and solutes being delivered to the distal tubule. The impairment of Na transport in the distal convoluted tubule induces natriuresis and water loss, while increasing the reabsorption of calcium in this segment in a manner unrelated to sodium transport.
- Amiloride also increases distal tubular calcium reabsorption and has been used as a therapy for idiopathic hypercalciuria.
- A combination of 25 mg of chlorthalidone plus 5 mg of amiloride daily led to a substantial reduction in urine calcium in Dent's patients, but urine pH was "significantly higher in patients with Dent’s disease than in those with idiopathic hypercalciuria (P < 0.03), and supersaturation for uric acid was consequently lower (P < 0.03)."
- For patients with osteomalacia, vitamin D or derivatives have been employed, apparently with success.
- Some lab tests on mice with CLC-5-related tubular damage showed a high-citrate diet preserved kidney function and delayed progress of kidney disease.
Standard intravenous preparations of potassium phosphate are available and are routinely used in malnourished patients and alcoholics. Oral supplementation is also useful where no intravenous treatment are available. Historically one of the first demonstrations of this was in concentration camp victims who died soon after being re-fed: it was observed that those given milk (high in phosphate) had a higher survival rate than those who did not get milk.
Monitoring parameters during correction with IV phosphate
- Phosphorus levels should be monitored after 2 to 4 hours after each dose, also monitor serum potassium, calcium and magnesium. Cardiac monitoring is also advised.
Alkaptonuria does not appear to affect life expectancy, although the last study on the topic is from 1985. The main impact is on quality of life; many people with alkaptonuria have disabling symptoms such as pain, poor sleep and breathing symptoms. These generally start in the fourth decade. The average age at requiring joint replacement surgery is 50–55 years.
Since the conversion of dihydroxyphenylserine (Droxidopa; trade name: Northera; also known as L-DOPS, L-threo-dihydroxyphenylserine, L-threo-DOPS and SM-5688), to norepinephrine bypasses the dopamine beta-hydroxylation step of catecholamine synthesis, L-Threo-DOPS is the ideal therapeutic agent. In humans with DβH deficiency, L-Threo-DOPS, a synthetic precursor of noradrenaline, administration has proven effective in dramatic increase of blood pressure and subsequent relief of postural symptoms.
L-DOPS continues to be studied pharmacologically and pharmacokinetically and shows an ability to increase the levels of central nervous system norepinephrine by a significant amount. This is despite the fact that L-DOPS has a relative difficulty crossing the blood-brain barrier when compared to other medications such as L-DOPA. When used concurrently, there is evidence to show that there is increased efficacy as they are both intimately involved and connected to the pathway in becoming norepinephrine.
There is hope and evidence that L-DOPS can be used much more widely to help other conditions or symptoms such as pain, chronic stroke symptoms, and progressive supranuclear palsy, amongst others. Clinically, L-DOPS has been already shown to be helpful in treating a variety of other conditions related to hypotension including the following:
- Diabetes induced orthostatic hypotension
- Dialysis-induced hypotension
- Orthostatic intolerance
- Familial amyloidotic polyneuropathy
- Spinal Cord Injury related hypotension
Empirical evidence of mild effectiveness has been reported using mineralocorticoids or adrenergic receptor agonists as therapies.
Other medications that can bring relief to symptoms include:
- phenylpropanolamine- due to pressor response to vascular α-adrenoceptors
- indomethacin
Vitamin C (ascorbic acid) is also a required cofactor for the Dopamine beta hydroxylase enzyme. Recent research has shown that vitamin C rapidly catalyzes the conversion of dopamine to norepinephrine through stimulation of the dopamine beta hydroxylase enzyme.
Resection of the tumor is the ideal treatment and results in correction of hypophosphatemia (and low calcitriol levels) within hours of resection. Resolution of skeletal abnormalities may take many months.
If the tumor cannot be located, treatment with calcitriol (1-3 µg/day) and phosphorus (1-4 g/day in divided doses) is instituted. Tumors which secrete somatostatin receptors may respond to treatment with octreotide. If hypophosphatemia persists despite calcitriol and phosphate supplementation, administration of cinacalcet has been shown to be useful
Untreated individuals with DβH deficiency should avoid hot environments, strenuous exercise, standing still, and dehydration.
There has been no specific drug therapy developed for hepatitis, with the exception of hepatitis C. Patients are advised to rest in the early stages of the illness, and to eat small, high-calorie, high-protein meals in order to battle anorexia. Larger meals are more easily tolerated in the morning, for patients often experience nausea later in the day. Although high-protein meals are recommended, protein intake should be reduced if signs of precoma — lethargy, confusion, and mental changes — develop.
In acute viral hepatitis, hospitalization is usually required only for patients with severe symptoms (severe nausea, vomiting, change in mental status, and PT greater than 3 seconds above normal) or complications. If the patient experiences continuous vomiting and is unable to maintain oral intake, parenteral nutrition may be required.
In order to relieve nausea and also prevent vomiting, antiemetics (diphenhydramine or prochlorperazine) may be given 30 minutes before meals. However, phenothiazines have a cholestatic effect and should be avoided. The resin cholestyramine may be given only for severe pruritus.
D-Bifunctional protein deficiency (officially called 17β-hydroxysteroid dehydrogenase IV deficiency) is an autosomal recessive peroxisomal fatty acid oxidation disorder. Peroxisomal disorders are usually caused by a combination of peroxisomal assembly defects or by deficiencies of specific peroxisomal enzymes. The peroxisome is an organelle in the cell similar to the lysosome that functions to detoxify the cell. Peroxisomes contain many different enzymes, such as catalase, and their main function is to neutralize free radicals and detoxify drugs, such as alcohol. For this reason peroxisomes are ubiquitous in the liver and kidney. D-BP deficiency is the most severe peroxisomal disorder, often resembling Zellweger syndrome.
Characteristics of the disorder include neonatal hypotonia and seizures, occurring mostly within the first month of life, as well as visual and hearing impairment. Other symptoms include severe craniofacial disfiguration, psychomotor delay, and neuronal migration defects. Most onsets of the disorder begin in the gestational weeks of development and most affected individuals die within the first two years of life.
D-Glyceric Acidemia should not be confused with L-Glyceric Acidemia (a.k.a. L-glyceric aciduria, a.k.a. primary hyperoxaluria type II ), which is associated with mutations in the "GRHPR" (encoding for the enzyme 'glyoxylate reductase/hydroxypyruvate reductase').
In season 2 of the USA Network series Royal Pains, Reshma Shetty (as Divya Katdare) diagnoses a storm chaser (Jamie Ray Newman) with recurring fractures to have tumor-induced osteomalacia.
Treatment for renal osteodystrophy includes the following:
- calcium and/or native vitamin D supplementation
- restriction of dietary phosphate (especially inorganic phosphate contained in additives)
- phosphate binders such as calcium carbonate, calcium acetate, sevelamer hydrochloride or carbonate, lanthanum carbonate, sucroferric oxyhydroxide, ferric citrate among others
- active forms of vitamin D (calcitriol, alfacalcidol, paricalcitol, maxacalcitol, doxercalciferol, among others)
- cinacalcet
- renal transplantation
- haemodialysis five times a week is thought to be of benefit
- parathyroidectomy for symptomatic medication refractive end stage disease
D-Glyceric Acidemia (a.k.a. D-Glyceric Aciduria) is an inherited disease, in the category of inborn errors of metabolism. It is caused by a mutation in the gene "GLYCTK", which encodes for the enzyme "glycerate kinase".
The majority of patients is initially screened by enzyme assay, which is the most efficient method to arrive at a definitive diagnosis. In some families where the disease-causing mutations are known and in certain genetic isolates, mutation analysis may be performed. In addition, after a diagnosis is made by biochemical means, mutation analysis may be performed for certain disorders.
Alternatively, a single-dose therapy is used for instance if there are concerns regarding the patient's compliance. The single-dose therapy can be given as an injection, but is normally given in form of an oral medication.
Increasing fluid intake to yield a urine output of greater than 2 liters a day can be advantageous for all patients with nephrocalcinosis. Patients with hypercalciuria can reduce calcium excretion by restricting animal protein, limiting sodium intake to less than 100 meq a day and being lax of potassium intake. If changing ones diet alone does not result in an suitable reduction of hypercalciuria, a thiazide diuretic can be administered in patients who do not have hypercalcemia. Citrate can increase the solubility of calcium in urine and limit the development of nephrocalcinosis. Citrate is not given to patients who have urine pH equal to or greater than 7.
For treating rickets, the American Academy of Pediatrics (AAP) has recommended that pediatric patients receive an initial two- to three-month treatment of "high-dose" vitamin D therapy. In this regime, the daily dose of cholecalciferol is 1,000 IU for newborns, 1,000 to 5,000 IU for 1- to 12-months old infants, and 5,000 IU for patients over 1 year of age.
For adults, other dosages have been called for. A review of 2008/2009 recommended dosages of 1,000 IU cholecalciferol per 10 ng/ml required serum increase, to be given daily over two to three months. In another proposed cholecalciferol loading dose guideline for vitamin D-deficient adults, a weekly dosage is given, up to a total amount that is proportional to the required serum increase (up to the level of 75 nml/l) and, within certain body weight limits, to body weight.
Sirolimus is an mTOR inhibitor that stabilizes lung function and improves some measures of life in LAM patients. It is approved by the FDA for use in LAM, based on the results of the Multicenter International LAM Efficacy and Safety of Sirolimus (MILES) Trial. MILES data supports the use of sirolimus in patients who have abnormal lung function (i.e. FEV1<70% predicted). Whether the benefits of treatment outweigh the risks for asymptomatic LAM patients with normal lung function is not clear, but some physicians consider treatment for declining patients who are approaching the abnormal range for FEV1. Sirolimus also appears to be effective for the treatment chylous effusions and lymphangioleiomyomatosis. The benefits of sirolimus only persist while treatment continues. The safety of long term therapy has not been studied.
Potential side effects from mTOR inhibitors include swelling in the ankles, acne, oral ulcers, dyspepsia, diarrhea, elevation of cholesterol and triglycerides, hypertension and headache. Sirolimus pneumonitis and latent malignancy are more serious concerns, but occur infrequently. Sirolimus inhibits wound healing. It is important to stop therapy with the drug for 1–2 weeks before and after elective procedures that require optimal wound healing. Precautions must be taken to avoid prolonged sun exposure due to increased skin cancer risk.
Treatment with another mTOR inhibitor, everolimus, was reported in a small, open-label trial to be associated with improvement in FEV1 and six-minute walk distance. Serum levels of VEGF-D and collagen IV were reduced by treatment. Adverse events were generally consistent with those known to be associated with mTOR inhibitors, although some were serious and included peripheral edema, pneumonia, cardiac failure and "Pneumocystis jirovecii" infection. Escalating doses of everolimus were used, up to 10 mg per day; higher than what is typically used clinically for LAM.
Serum VEGF-D concentration is useful, predictive and prognostic biomarker. Higher baseline VEGF-D levels predicts more rapid disease progression and a more robust treatment response.
Hormonal approaches to treatment have never been tested in proper trials. In the absence of proven benefit, therapy with progesterone, GnRh agonists (e.g., Lupron, goserelin) and tamoxifen are not routinely recommended. Doxycycline had no effect on the rate of lung function decline in a double blind trial.
Sirolimus is often effective as first-line management for chylothorax. If chylous leakage or accumulations persist despite treatment, imaging with heavy T2 weighted MRI, MRI lymphangiography or thoracic duct lymphangiography can be considered. Pleural fusion procedures can be considered in refractory cases.
Bile acid sequestrants are the main agents used to treat bile acid malabsorption. Cholestyramine and colestipol, both in powder form, have been used for many years. Unfortunately many patients find them difficult to tolerate; although the diarrhea may improve, other symptoms such as pain and bloating may worsen. Colesevelam is a tablet and some patients tolerate this more easily. A proof of concept study of the farnesoid X receptor agonist obeticholic acid has shown clinical and biochemical benefit.
As of March 15, 2016, Novartis Pharmaceuticals is conducting a phase II clinical study involving a farnesoid X receptor agonist named LJN452.
Nutritional osteomalacia responds well to administration of 2,000-10,000 IU of vitamin D3 by mouth daily. Vitamin D3 (cholecalciferol) is typically absorbed more readily than vitmin D2 (ergocalciferol). Osteomalacia due to malabsorption may require treatment by injection or daily oral dosing of significant amounts of vitamin D3.
Prevention of osteomalacia rests on having an adequate intake of vitamin D and calcium. Vitamin D3 Supplementation is often needed due to the scarcity of Vitamin D sources in the modern diet.