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Polypeptide levels increase during acute onset of hepatic porphyrias.

Hepatic porphyrias are characterized by neurological symptoms manifested by abdominal pain, neuropathies and mental aberrations. Porphyrins are ubiquitous and essential biochemical constituents of living beings acting as mediators of oxidation reaction in the metabolism of the steroid, drugs, environmental chemicals or as a mean of exchanging gases, such as oxygen and carbon dioxide between the environment and the tissue of the body using endogenous polypeptide properties. The different porphyrins arising from the arrangement of normal heme synthesis are characterized by an accumulation and excretion of specific intermediate porphyrins and/or of precursors exerting toxic effect, initiating cascades of generations of polypeptides, neurotransmitters and gut-brain axis peptide responsible for the symptoms of clinical status. We studied polypeptide levels in 27 patients (19 females, 8 males) presenting acute attack of hepatic porphyria: 2 with ALA dehydratase-deficient porphyria; 9 with acute intermittent porphyria; 12 with porphyria cutanea tarda and 4 with variegate porphyria. During acute attacks of porphyria, polypeptides were found to be constantly increased: vasoactive intestinal polypeptide (VIP); neurotensin (NT); substance P; pancreatic polypeptide; gastrin-releasing peptide; gastrin and motilin. Administration of the somatostatin (antagonizing polypeptide), which was undetectable or low before treatment, apparently alleviated the acute symptomatology. Elevated levels of polypeptides, at least partly, contribute to appearance of acute symptoms in porphyria patients.

Acute Disease↗

L-tryptophan: a common denominator of biochemical and neurological events of acute hepatic porphyria?

Hepatic porphyrias are disorders of heme synthesis characterized by genetically determined lesions of one of the key enzymes of heme synthesis. In carriers of such lesions, several factors (drugs, environmental chemicals, or diet) precipitate acute and often fatal attacks of neurologic dysfunction, which are promptly relieved by intravenous infusion of heme. However, the mechanism of such heme-induced amelioration remains elusive. To probe this mechanism, the biochemical events triggered by acute hepatic heme deficiency were examined in an animal model of chemically induced porphyria. Acute hepatic heme depletion in porphyric rats was found to impair hepatic tryptophan pyrrolase activity which, in turn, elevated tryptophan and 5-hydroxytryptamine turnover in the brain. These alterations in porphyric rats were dramatically reversed by parenteral heme administration. These findings suggest that increased tryptophan and 5-hydroxytryptamine in the nervous system may be responsible for the neurologic dysfunctions observed in humans with acute attacks of hepatic porphyria.

Animals↗

[Cryomacroglobulinemic purpura with liver cirrhosis and hepatic porphyria].

Hepatic porphoria and histologically verified cirrhosis, teleangiectasia, purpose, papular skin lesions existing for eight years, as well as cryomacroglobulin were found in a 49 year old man. Pathogenetically the liver disease is considered to be the primary event, which was accompanied by secondary cryoglobulinemia. IgG and IgM type of thrombus in the vessels and of small granular deposits corresponding to the type of cryoprotein in the blood, were detected in the vessel walls of the upper part in the dermis and along these vessels of both purpuri and papular skin lesions. Immunoprecipitates could be revealed by FTC-labelled antihuman complement. In the skin lesions porphyrin could not be demonstrated. The investigation of cryoglobulin and of porphyrin disorders is reasonable in every patient with purpura accompanying pathological liver processes.

Cryoglobulins↗

[Chronic hepatic porphyria and hepatitis B and C virus infections].

BACKGROUND: It is known that in patients with porphyria cutanea tarda (PCT) there is an increased prevalence of the hepatitis B virus (HBV) and the hepatitis C virus (HCV). The incidence of anti-HCV in PCT in our country is 21.7% in estimations by the second generation method, however, the incidence of HBV in PCT was not assessed so far. METHODS AND RESULTS: In 60 patients with PCT antigens and antibodies against HBV and HCV were assessed (by the anti-HCV third generation ELISA method) and in subjects with signs of HBV or HCV. HBV DNA and HCV RNA were assessed by the method of the polymerase chain reaction. PCT without detectable HBV or HCV infection was found in 45 subjects (68%). HBV infection only was confirmed in seven subjects (10.6%), however none of the patients had positive HBsAg in serum. All had only antibodies against HBV. HCV infection only was detected in seven patients (10.6%) and HBV and HCV co-infection also in seven patients (10.6%). In the group of patients with HBV and HCV co-infection there was not a single HBsAg positive subject. The mean ALT serum activity was significantly higher as compared with subjects with HBV or HCV infection only (p < 0.05) and the histological finding on liver biopsy was more serious. CONCLUSION: HBV (21%) and HCV (21%) infection participates significantly in the clinical picture of PCT. A special subgroup is formed by patients with PCT and HBV and HCV co-infection who have as a rule a higher ALT activity and more severe histological changes in the liver. The incidence of HBV and HCV infection in PCT in the Czech Republic is double as compared with Germany or Great Britain.

Adult↗

Effects of clonidine in a primed rat model of acute hepatic porphyria.

Acute hepatic porphyrias can be induced by several drugs and acute attacks of porphyrias are often associated with severe hypertension. Therefore it is important to know if an antihypertensive drug used has porphyrogenic potency or not. As previously demonstrated in normal rats the alpha-receptor blocker clonidine (CAS 4205-90-7) has no significant influence on the porphyrin metabolism. Pretreatment of rats with 3,5-diethoxycarbonyl-1,4-dihydrocollidine (DDC) or allyl-isopropyl-acetamide (AIA) induces hepatic delta-aminolaevulinic acid synthase (ALA-S) and increases the urinary excretion of porphyrin precursors (ALA and PBG) comparable to the latent phase of acute hepatic porphyrias in humans. Clonidine did not induce hepatic ALA-S or urinary excretion of ALA or PBG in normal as well as in DDC or AIA pretreated rats. Moreover the induction of P4501A1 (7-ethoxyresorufin-O-deethylase) by DDC was abolished by simultaneous application of clonidine. From these findings one can probably conclude that clonidine is a safe drug in human acute hepatic porphyria.

5-Aminolevulinate Synthetase↗

[The course of acute hepatic porphyria].

Acute hepatic porphyrias are the diseases dependent on the congenital metabolic defects of the hem biosynthesis. The diagnosis of porphyria only on the grounds of clinical picture is extremely difficult as it is presented by the variety of symptoms, often imitating other diseases. In each case the diagnosis must be confirmed by the biochemical and enzymatic investigations. In the paper we described different clinical courses of the acute hepatic porphyrias. The acquaintance with the symptoms of porphyrias enables to decrease the number of complications connected with diagnostic and therapeutic errors what is still a serious economic problem.

Acute Disease↗

[Liver cirrhosis and chronic hepatic porphyria].

Chronic hepatic porphyrias (CHP) are associated with different degrees of liver damage. They range from minimal histological changes to cirrhosis and primary liver carcinomas. Forty patients with early stages of porphyrias were compared to 85 patients with clinically manifest porphyrias, Porphyria cutanea tarda. This comparison resulted in the fact that cirrhosis occurred more often in early (or latent) stages (65%) than in PCT (31%) confirmed by laparoscopy. Thus the severity of the liver disease does not depend on the duration and intensity of cutaneous symptoms or pathobiochemical syndromes but they more often depend on the long-term influence of so-called trigger factors, among them above all alcohol and iron overloading. We conclude that the proof of latent CHP has an index function for severer liver damage.

Female↗

Hereditary uroporphyrinogen-decarboxylase deficiency predisposing porphyria cutanea tarda (chronic hepatic porphyria) in females after oral contraceptive medication.

Porphyria cutanea tarda (PCT) was diagnosed in 27 women aged 23-48 years (mean, 35 years) who had been under oral-hormonal-contraceptive medication for 1-18 years, in 3 women under substitutional estrogen treatment in the menopause, and in 2 men aged 65 and 76 years after estrogen treatment of prostatic carcinoma. In all patients, total urinary porphyrin excretion was elevated, with an average uro- and heptacarboxyporphyrin predominance of 88%, thus proving PCT. Of the patients, 84% showed a significant decrease of erythrocyte uroporphyrinogen-decarboxylase (UD; EC 4.1.1.37) activity to approximately 50% of control levels suggesting a hereditary predisposition for the development of a chronic hepatic porphyria. Estrogens and alcohol are capable of reducing hepatic UD activity. Women with hereditary red cell UD deficiency may be regarded as predisposed to PCT when under estrogen intake, especially in combination with the potentiating influence of alcohol and chronic liver disease. Normal erythrocyte UD values in patients with additive alcohol consumption may implicate a stronger inhibitory effect for alcohol on UD, suggesting a merely toxic form of chronic hepatic porphyria.

Adult↗

[Anesthesia and acute hepatic porphyrias].

Acute hepatic porphyrias are inherited disorders of heme biosynthesis. A characteristic feature of acute porphyrias is the occurrence of acute attacks which are often precipitated by drugs. Many of the commonly used anaesthetic agents may trigger such a potentially lethal attack. Thus, only safe agents should be administered to predisposed patients. Recommendations given are based on results from animal experiments and on a series of anecdotal reports. Regional anaesthesia is presented as anaesthetic technique of choice. General anaesthesia should be based on a fentanyl-nitrous oxide regimen, with propofol as induction agent. In the case of an acute attack, treatment consists of glucose and haematin administration.

Anesthetics↗

[Porphyria cutanea tarda (chronic hepatic porphyria): new aspects on pathogenesis, diagnosis and therapy with a review of the workshop, "Cutaneous porphyrias" at the 17th World Congress of Dermatology in Berlin 1987].

Porphyria cutanea tarda (PCT) is the most frequent type of porphyria. As a rule, it is associated with chronic liver disease. The disturbance of the hepatic porphyrin metabolism is regarded as the cause and center of the disease. Thus PCT is also designated as chronic hepatic porphyria. Reduced activity of hepatic uroporphyrinogen decarboxylase is considered the most important prerequisite for the development of PCT. The cutaneous manifestations are preceded by non-cutaneous latent phases of various degrees. These phases may be proved by urinary porphyrin studies, especially by the increase of uro- and heptacarboxyporphyrins. The hereditary form of PCT can be identified by the determination of the uroporphyrinogen decarboxylase in erythrocytes. The enzyme deficiency in red blood cells follows dominant autosomal inheritance. Alcohol and estrogens are the predominant factors of clinical manifestation. The application of chloroquine in low doses has proved an effective treatment. The present review includes a report on the workshop "Cutaneous Porphyrias", which reflects the clinical, toxic, pharmacogenetic, pathophysiological, enzymologic, and molecular aspects from the authors' point of view.

Chloroquine↗

Vinyl chloride-induced hepatic coproporphyrinuria with transition to chronic hepatic porphyria.

A chronic hepatic disorder of porphyrin metabolism was found in 36 workers with vinyl chloride (VC)-induced hepatic injury following long-time industrial exposure. Pathologic porphyrinuria, especially secondary coproporphyrinuria with transition to subclinical chronic hepatic porphyria, is a consistent pathobiochemical parameter for the recognition of VC hepatic lesions. The porphyrinuria is of diagnostic value for the incipient toxic phase. Erythrocyte uroporphyrinogen decarboxylase activity studied in six cases with initial chronic hepatic porphyria was normal, suggesting that VC affects only this enzyme in the liver.

Chemical Industry↗

Human hereditary hepatic porphyrias.

The human hereditary hepatic porphyrias are diseases due to marked deficiencies of enzymes in the heme biosynthetic pathway. Porphyrias can be classified as either hepatic or erythroid, depending on the major production site of porphyrins or their precursors. The pathogenesis of inherited hepatic porphyrias has now been defined at the molecular level. Some gene carriers are vulnerable to a range of exogenous and endogenous factors, which may trigger neuropsychiatric and/or cutaneous symptoms. Early diagnosis is of prime importance since it makes way for counselling. In this article we present an overview of recent advances on hepatic porphyrias: 5-aminolevulinic acid dehydratase deficiency porphyria, acute intermittent porphyria (AIP), porphyria cutanea tarda (PCT), hereditary coproporphyria (HC), and variegate porphyria (VP).

Animals↗

Hepatic porphyrias in children.

Clinically overt hepatic porphyria is uncommon in children. The autosomal dominant acute hepatic porphyrias, acute intermittent porphyria (AIP), variegate porphyria (VP) and hereditary coproporphyria (HCP), are rarely present before puberty. Identification of asymptomatic children who have inherited these disorders is an important aspect of the management of the disease in their families and requires either enzymatic or DNA methods. Homozygous variants of AIP, VP and HCP usually present in early childhood and have phenotypes of variable severity. Mutational analysis is currently elucidating the relationship between these disorders and their autosomal dominant counterparts. 5-Aminolaevulinate dehydratase deficiency porphyria is a rare, autosomal recessive acute porphyria that may present at any age. Two cutaneous hepatic porphyrias are seen in children. Porphyria cutanea tarda (PCT), although mainly an adult disease, has been reported in young children with the autosomal dominant (type II) form of the disorder. Hepatoerythropoietic porphyria usually develops before the age of 2 years; patients are homo- or heteroallelic for uroporphyrinogen decarboxylase mutations, at least one of which is known to cause type II PCT.

Child↗

Safety of general anaesthesia and surgery in acute hepatic porphyria.

Patients with acute hepatic porphyria are denied essential operations because of concern that general anaesthesia and surgery will precipitate a life threatening porphyric crisis. This study assessed the safety of surgery under general anaesthesia in these patients. A combined prospective and retrospective case note study, with a biochemical study, was conducted in 25 patients with acute hepatic porphyria undergoing 38 surgical operations. Clinical outcome measures were survival and occurrence of porphyric crisis after surgery. The biochemical activity of porphyria was assessed by measurement of the perioperative 24 hour excretion of the haem precursors delta amino-laevulinic acid (ALA) and porphobilinogen (PBG). There were no deaths or crises after 29 operations in 19 patients who were known to have porphyria before their surgery, and therefore given only appropriate drugs. These operations include such major procedures as mitral valve replacement, hip replacement, coronary artery grafting, cholecystectomies, and renal transplantation. In eight of these patients the urinary excretion of ALA and PBG were studied, and showed no sustained postoperative increase. Nine operations were performed in eight patients before the diagnosis of porphyria was known and who thus received routine anaesthetic agents. Seven of these patients developed a postoperative porphyric crisis. Two of them died. It is concluded therefore that even the most major surgery can be undertaken safely in patients with porphyria. The risk is for undiagnosed cases.

Acute Disease↗

[The hepatic porphyrias: experience with 105 cases].

Hepatic porphyria is a rare metabolic syndrome caused by abnormal enzyme activity in heme biosynthesis. Between 1974 and 1991; 105 patients have met criteria for diagnosis of hepatic porphyria based on typical clinical findings and/or laboratory abnormalities. According to type, 42% had porphyria cutanea tarda, 21% porphyria variegate, 15% protoporphyria, 6.7% acute intermittent porphyria, 6.7% coproporphyria and 1.9% porphyria due to porphobilinogen deficit. A proper classification was not established in 6.7% of patients. Porphyria cutanea tarda was more common in males (70%) and porphyria variegata, in females (90%). A family history of the disease was present in 33% of patients; 20% of patients were of European descent and 4% of Mapuche descent. Diagnosis was usually established in the third decade, somewhat later in porphyria cutanea tarda (45 years of age) and very early in protoporphyria. 10% of patients were asymptomatic and 29 patients developed at least one porphyric crisis. These were related to pregnancy in 6 patients, to hormone administration in 7, to antibiotics in 5. No cause was established in 21 cases. Severe crisis were successfully treated with Hematin. Venipuncture was used to treat 50% of patients with porphyria cutanea tarda with 95% success. Thus, hepatic porphyria is recognized with increasing frequency and can be treated successfully in most cases.

Adolescent↗

Studies in porphyria. V. Drug oxidation rates in hereditary hepatic porphyria.

The mean plasma half-life (T1/2) of antipyrine was prolonged (21.69 +/- 1.92 hr) in a group of 10 patients with hereditary hepatic porphyria, 8 of whom had acute intermittent porphyria (AIP) confirmed by decreased erythrocyte uroporphyrinogen-1-synthetase (URO-S) activities and 2 of whom had mixed hepatic porphyria, in comparison to the mean of 20 normal control subjects (12.65 +/- 0.86 hr, p less than 0.01). Antipyrine T1/2 was especially prolonged in patients with a history of more severe symptoms, but there was no correlation with the degree of elevation in urinary excretion of the porphyrin precursors delta-aminolevulinic acid (ALA) and porphobilinogen (PBG). In 7 completely latent carriers of the AIP gene defect who had normal urinary ALA and PBG levels, the elimination rates of antipyrine from plasma were entirely normal. Phenylbutazone T1/2s were normal in 10 porphyric patients tested. These results demonstrate that the cytochrome P-450-dependent enzyme system for oxidizing antipyrine, but not that for phenylbutazone, is impaired in some AIP individuals in whom the gene defect for the disorder is clinically expressed and that this impairment may be related to the severity of the disease. The partial decrease in URO-S activity characteristic of AIP does not result in a profound or generalized decrease in hepatic cytochrome P-450 function, however, even when there is sufficient derangement in the hepatic heme biosynthetic pathway to lead to excessive excretion of chemical intermediates in the pathway.

Adult↗