Morphologic alterations in patients with alpha-methyldopa-induced liver damage after short- and long-term exposure

Chronic liver injury induced by drugs: a systematic review

To examine the available literature and summarize what is known about chronic drug-induced liver injury. We reviewed PubMed/MEDLINE through March 2015. We developed a MEDLINE search strategy using PubMed medical subject heading terms chronic liver injury, hepatotoxicity, drug-induced liver injury, cirrhosis and chronic liver disease. We reviewed the reference list of included articles to identify articles missed in the database search. Chronic liver injury from drugs is more common than once thought with prevalence as high as 18% based on large national registries. Patients with cholestatic injury, age ≤65 years, and a long latency period (>365 days) are at increased risk. Of the most common drugs associated with drug-induced liver injury, antibiotics (amoxicillin-clavulanic acid, trimethoprim-sulfamethoxazole, azithromycin) are most likely to cause chronic injury. The presence of autoantibodies is common with chronic DILI, however, it is not diagnostic nor is it specific to autoimmune-like drug-induced liver injury. Immunosuppressive therapy may be necessary for individual cases of autoimmune-like drug-induced liver injury where cessation of the drug alone does not result in resolution of injury, however, the lowest dose should be used for the shortest duration with careful attention to the development of side effects. The effectiveness of treament of cholestatic liver injury with corticosteroids or ursodiol remains unclear. Cases of drug-induced fatty liver, nodular regenerative hyperplasia and peliosis hepatitis are less common subtypes of chronic drug-induced liver injury that deserve special consideration. A high degree of clinical suspicion is required for the diagnosis of chronic drug-induced liver injury and should be suspected in any patient with liver associated enzyme abnormalities that persist out past 6 months of initial presentation. Treatment with drug removal and/or immunosuppressive therapy appears to be effective for the majority of cases. More study into pharmacogenomics and personalized medicine may aid in predicting which patients will go on to develop chronic drug-induced liver injury.

Drug-induced autoimmune-like hepatitis

The clinical phenotype of classical autoimmune hepatitis can be mimicked by idiosyncratic drug-induced liver injury, and differentiation can be difficult. The goals of this review are to enumerate the major agents of drug-induced autoimmune-like hepatitis, describe the clinical findings and risk factors associated with it, detail the clinical tools by which to assess causality, discuss putative pathogenic mechanisms, and describe treatment and outcome. The frequency of drug-induced autoimmune-like hepatitis among patients with classical features of autoimmune hepatitis is 9%. Minocycline and nitrofurantoin are implicated in 90% of cases. Female predominance, acute onset, and absence of cirrhosis at presentation are important clinical manifestations. Genetic factors affecting phase I and phase II transformations of the drug, polymorphisms that protect against cellular oxidative stress, and human leukocyte antigens that modulate the immune response may be important pathogenic components. Clinical judgment is the mainstay of diagnosis as structured diagnostic methods for drug-induced liver injury are imperfect. The covalent binding of a reactive drug metabolite to a hepatocyte surface protein (commonly a phase I or phase II enzyme), formation of a neoantigen, activation of CD8 T lymphocytes with nonselective antigen receptors, and deficient immune regulatory mechanisms are the main bases for a transient loss of self-tolerance. Discontinuation of the offending drug is the essential treatment. Spontaneous improvement usually ensues within 1 month. Corticosteroid therapy is warranted for symptomatic severe disease, and it is almost invariably effective. Relapse after corticosteroid withdrawal probably does not occur, and its absence distinguishes drug-induced disease from classical autoimmune hepatitis.

Drug-induced liver injury: Is it somehow foreseeable?

The classic view on the pathogenesis of drug-induced liver injury is that the so-called parent compounds are made hepatotoxic by metabolism (formation of neo-substances that react abnormally), mainly by cytochromes P-450 (CYP), with further pathways, such as mitochondrial dysfunction and apoptosis, also playing a role. Risk factors for drug-induced liver injury include concomitant hepatic diseases, age and genetic polymorphisms of CYP. However, some susceptibility can today be predicted before drug administration, working on the common substrate, by phenotyping and genotyping studies and by taking in consideration patients’ health status. Physicians should always think of this adverse effect in the absence of other clear hepatic disease. Ethical and legal problems towards operators in the health care system are always matters to consider.

Liver injury in subjects occupationally exposed to chemicals in low doses

The hepatic injury developing during occupational exposure to chemicals was investigated in 23 male patients, aged 23-49 years, by comparing case histories, liver function tests, hepatic microsomal enzyme activities in vivo and in vitro with histology. The subjects, 15 chemical industry workers and 8 painters, had disturbed liver tests after years of exposure to solvents, paints and lacquers. Characteristic for the patients was a 2-4-fold increase in serum aminotransferases associated with normal liver or reactive hepatitis with or without fatty liver. All patients, except subjects with fatty change, had metabolically active liver which was reflected as adaptive and toxic changes in cellular ultrastructure. The biochemical liver tests normalized within 3-6 weeks after cessation of the exposure. The findings demonstrate that occupational exposure to chemical solvents may insidiously damage the liver. The injury is detectable by biochemical, metabolic and histological investigations in the early phase.

Liver damage in nurses handling cytostatic agents

Three consecutive head nurses developed liver injury after years of handling cytostatic drugs. They had neurological symptoms associated with elevated serum alanine amino-transferase (ALAT) and alkaline phosphatase (ALP) levels. Liver histology showed portal hepatitis with piecemeal necrosis in one of them, the others had hepatic fibrosis and fat accumulation. The subjects' livers were metabolically active as reflected by adaptive and toxic changes in cellular ultrastructure. After withdrawal of the drugs, serum ALAT and ALP values fluctuated between normal and 2-3 times elevated. Follow-up biopsies demonstrated an increase in collagen fibres and a decrease in microsomal enzyme activity, as reflected by arylhydrocarbon hydroxylase activity in vitro. The findings suggest that handling of cytostatic drugs may insidiously damage the liver, which, with time, seems to lead to irreversible fibrosis.

Diabetes and elimination of antipyrine in man: an analysis of 298 patients classified by type of diabetes, age, sex, duration of disease and liver involvement

Effects of diabetes on hepatic drug metabolism in man has not yet been adequately clarified. Two hundred ninety-eight diabetic patients, classified by type of the disease, age, gender, duration of therapy and liver involvement, were investigated. The antipyrine plasma clearance rate and cytochrome P450 content determinations in liver biopsies of subjects with diagnostic liver biopsy were used as indices of hepatic drug metabolising capacity. Drug metabolism was reduced as a function of age. Antipyrine elimination rate was dependent on the type of diabetes (type 1 versus type 2) and gender. Untreated type 1 patients eliminated antipyrine rapidly and insulin treatment normalised antipyrine elimination (clearance rates 89.5 +/- 20.3 versus 58.8 +/- 17.2 ml/min.; P<0.001). Males aged 16-59 years, but not over 60, who responded insufficiently to insulin therapy, had a rapid antipyrine elimination, which could be normalised by readjustment of insulin administration. Women with insufficient glucose control on insulin therapy had antipyrine elimination rate comparable to controls. Among type 2 diabetic patients, women metabolised antipyrine normally, but men over 40 years of age showed a reduced antipyrine metabolism.

IN CONCLUSION

Drug metabolism in diabetes is affected by the type of disease, therapy and its effectiveness, and age and gender of the patients. These factors should be taken into account when evaluating overall drug metabolism in diabetic patients. This is especially important when investigating pharmacokinetics of new drugs for diabetic patients at different phases of the disease.

Age and cytochrome P450-linked drug metabolism in humans: an analysis of 226 subjects with equal histopathologic conditions

OBJECTIVES

The effect of aging on drug metabolism in humans has not yet been completely described.

METHODS

Two hundred twenty-six patients with equal histopathologic conditions were investigated. The cytochrome P450 contents in the liver biopsy samples, the plasma antipyrine clearance rates after oral administration and, as an independent control of vitality, serum testosterone levels were determined.

RESULTS

Cytochrome P450 content in subjects from 20 to 29 years of age was 7.2 +/- 2.6 nmol.gm-1, increased during the fourth decade (+7.2%, p = NS), declined after 40 years (-16%, p < 0.01) to a level that remained unaltered up to 69 years, and declined further after 70 years (-32%, p < 0.001). The antipyrine (phenazone) clearance rate in young subjects was 46.4 +/- 18.5 ml.min-1, remained unaltered during the fourth decade, and declined after 40 years by a rate of 0.34 ml.min-1 per year toward old age (-29%, p < 0.001). The half-life in young subjects was 9.5 +/- 2.0 hours and increased after 30 years toward old age (+26%, p < 0.001). The volume of antipyrine distribution, 0.46 +/- 0.12 L.kg-1 in young subjects, decreased after 30 years (-11%). In line with the testosterone content, the decrease in drug metabolism was equal in both sexes.

CONCLUSION

This study shows a reduction of in vitro and in vivo drug metabolism with age in humans. The data suggest that at least three age groups--young, middle-aged, and elderly--should be included in the evaluation of the pharmacokinetics of a new drug. The reduction of drug metabolism (-30%) after 70 years of age indicates that care is needed in the prescription of drugs for elderly subjects.

Experimental biliary fibrosis correlates with increased numbers of fat-storing and Kupffer cells, and portal endotoxemia

In the present study, we have investigated the correlation between hepatic fibrosis in rats subjected to bile duct ligation, the numbers of Kupffer and fat-storing cells, and the level of endotoxin in both the portal and systemic circulation. The extent of hepatic fibrosis was measured by morphometry. Kupffer cells were identified by indirect immunoperoxidase staining using ED-2 anti-macrophage antibody. Fat-storing cells were stained with DE-B-5 anti-desmin antibody. Endotoxin levels were determined by the Limulus Lysate test. Following bile duct ligation, connective tissue septa rapidly developed in periportal areas. After 1 week, the volume density of connective tissue had increased from 0.6 +/- 0.1% in control animals to 3.8 +/- 1.1%. After 2 weeks, this volume increased to 19.9 +/- 1.3%, and after 3 weeks to 34.3% +/- 2.7%. The number of periportal fat-storing cells increased 2.8-fold during the first 2 weeks, whereas pericentral fat-storing cells increased only 1.7-fold. After 2 weeks, no further increase was observed. During the first week of bile duct ligation, the number of Kupffer cells increased nearly two-fold. Thereafter, no further increase was detected. In control rats, only two of ten rats showed low amounts of endotoxin in the portal blood. Portal endotoxemia increased with time after bile duct ligation. After 3 weeks, all rats were positive. The measured endotoxin levels were approximately 7 times higher than in control rats. We conclude that the development of fibrosis secondary to experimental bile duct ligation is accompanied by protal endotoxemia, and increases in the numbers of Kupffer and periportal fat-storing cells. We found a significant correlation between portal endotoxemia, the number of Kupffer and fat-storing cells, and the extent of fibrous septa, supporting the view that high endotoxemia levels coincide with Kupffer cell activation and fibrogenesis.

Biliary cystadenoma of the liver with elevated CA 19-9

A case of intrahepatic biliary cystadenoma with mesenchymal stroma is reported. The tumor was associated with strikingly elevated serum and intracystic levels of the tumor-associated antigen CA19-9. Two months after surgical enucleation, serum CA 19-9 levels returned to normal.

Immunogenicity studies of a synthetic antigen of alpha methyl dopa

Since the idiosyncratic liver toxicity of methyl dopa (L-alpha-methyl-3,4- dihydroxy-phenylalanine) may be due to immune mediated mechanisms, immunologic tools are needed to detect methyl dopa induced antibody and antigen. Hapten (methyl dopa)--carrier (albumin) conjugates were synthesized to generate antibodies reactive with this drug. Studies were also conducted to test the immunogenicity of this hapten-carrier conjugate and its cross reactivity with methyl catechol and levodopa. Methyl dopa (MD), levodopa (LD) or methyl catechol (MC) were conjugated to rabbit serum albumin (RSA) under high pH (base) conditions or by a tyrosinase (tyr) catalyzed reaction. Under the base conjugation conditions, MD-RSA, LD-RSA and MC-RSA conjugates were produced at higher hapten: carrier ratios than conjugates produced by the enzyme catalyzed reaction. Rabbits were subsequently immunized with either MD-RSA(base) or MD-RSA(tyr). Antibodies elicited by MD-RSA(base) had marked reactivity to the carrier protein, albumin, whereas antibodies elicited by MD-RSA(tyr) did not. In addition, reactivity of anti-MD antibody was equal to or greater with MC-RSA than reactivity with either MD-RSA or LD-RSA. This work suggests that the conjugation method using the tyr catalyzed reaction produces the optimal immunogen with minimal modification of the carrier protein. In addition, the catechol moiety of MD, MC and LD appears to be the immunogenic epitope on these haptens.

Chronic hepatitis with fatty change

Ten patients with clinical features of chronic hepatitis showed on liver biopsy histologic evidence of chronic hepatitis plus predominantly moderate to severe fatty change. No patient had a history of excess alcohol intake, or prolonged intake of hepatotoxic drugs and steroids, and were not obese or malnourished. These cases differ from the reported cases of non-alcoholic steatohepatitis resembling alcoholic hepatitis as they occurred in relatively young health adults, predominantly males, who were not diabetic or obese. Mallory's hyalin in liver was absent in all cases. Ingestion of toxic substances was possible but no history was obtained to account for it. While these could be unusual cases of chronic non-A, non-B hepatitis, this can be only speculation until a serologic test for non-A, non-B hepatitis becomes available. Follow-up of eight patients for 1-3 years with liver biopsy showed that they had a relatively benign course with no evidence of progression to cirrhosis.

Insulin-mediated glucose metabolism is related to liver structure and microsomal function

The role of the liver in glucose metabolism was investigated in 24 consecutive patients undergoing diagnostic liver biopsy by comparing hepatic morphometry and microsomal enzyme activity in vivo (antipyrine) with fasting blood glucose (BG) and immunoreactive insulin (IRI) levels and with the metabolic clearance rate of insulin and the insulin sensitivity index. The patients had elevated BG and IRI levels and reduced insulin-mediated glucose metabolism, insulin sensitivity index, and microsomal enzyme activity as compared with controls. The insulin metabolic clearance rate did not diverge among the groups. Patients with fatty liver had a high BG associated with a reduced glucose disposal rate, whereas fasting IRI did not diverge when compared with other liver patients. Glucose disposal rate was related to the amount of unaltered liver (r2 = 0.640; p less than 0.001) and antipyrine metabolism (r = 0.631; p less than 0.01) and inversely related to the amount of fat (r2 = 0.585; p less than 0.01). The findings demonstrate that insulin-mediated glucose metabolism is related to liver structure and microsomal function. Accumulation of fat in the liver seems to be a major factor associated with reduced insulin sensitivity and glucose tolerance.

Liver disease in recipients of long-functioning renal allografts

After noting that hepatic failure was the leading cause of death in our transplant recipients whose renal allografts had functioned for more than five years, we reviewed retrospectively the post-transplant course of these patients to assess the long-term effect of liver disease in this population. Sufficient data was available to evaluate 184 of 217 long-term survivors (85%). Twenty-six patients (14%) experienced a doubling of SGOT and/or SGPT of greater than six months' duration and were defined as having chronic liver disease. The etiology of chronic liver disease was identified in 14 patients (54%), of whom 11 were HBsAg positive. Evidence of chronic hepatitis developed in only six of 26 patients (22%) during the first four years post transplant. Once enzyme abnormalities occurred, they were unremitting until death or end of the study in 73% of patients. Actuarial survival of patients with chronic liver disease was markedly decreased compared to long-surviving transplanted controls. Ten of the 12 deaths in patients with hepatocellular abnormalities were due to hepatic failure, of which eight occurred in the setting of extrahepatic sepsis. Chronic liver disease is a late complication of transplantation and is associated with significant mortality due to an increased susceptibility to overwhelming sepsis.

Treatment of liver cirrhosis with microsomal enzyme-inducing compound in the rat

The effect of therapy with a microsomal enzyme-inducing drug on the cirrhotic liver in male Wistar rats was investigated by morphological and biochemical means. The cirrhotic animals were treated with medroxyprogesterone acetate (MPA) 100 mg/kg body wt, i.p. daily for a week. In the cirrhotic rats liver weight was enhanced, liver protein content was increased while total liver DNA content remained unchanged upon MPA treatment. The hepatic regenerative nodule size increased, as determined by morphological means. Hepatic microsomal metabolic activity was improved, as seen by increases in NADPH-cytochrome P-450 reductase and aminopyrine N-demethylase activities and cytochrome P-450 content. Since the increases in liver protein content and metabolic activity were relatively greater in the cirrhotic than intact animals upon MPA treatment, it was suggested that the spontaneous regeneration associated with liver cirrhosis may affect the induction phenomenon. The results demonstrate that an enzyme inducer may have beneficial effects on the cirrhotic liver by elevating metabolic activity and parenchymal mass.

Carbohydrate intolerance associated with reduced hepatic glucose phosphorylating and releasing enzyme activities and peripheral insulin resistance in alcoholics with liver cirrhosis

Carbohydrate intolerance was investigated in 8 alcoholics with liver cirrhosis and in controls. Indices of carbohydrate metabolism, glucose and insulin levels after glucose loading, were compared with glucose phosphorylating (glucokinase, hexokinase) and releasing (glucose-6-phosphatase) enzymes. Comparison was also made with pericellular collagen in liver biopsies and with insulin sensitivity assessed by the euglycemic clamp technique and with conventional liver function tests including oral antipyrine test. Glucokinase activity was low or absent, hexokinase activity increased and the GK/HK ratio reduced. Glucose-6-phosphatase activity was lowered and insulin sensitivity decreased. Pericellular collagen was increased (P less than 0.001) and related to the fasting glucose (r0.593) and insulin levels (r0.526). Blood glucose was related to antipyrine metabolism (r-0.727) but not to the other liver tests. Glucose intolerance in cirrhosis seems to be associated with reduced glucose phosphorylating and liberating enzyme activities. Hyperinsulinaemia, developing secondarily, may then lead to insulin resistance.

Drug metabolism in diabetic subjects with fatty livers

The effect of fatty degeneration of liver parenchyma on drug metabolism was investigated in 21 obese non-insulin-dependent diabetic subjects by measuring plasma antipyrine kinetics, hepatic cytochrome P-450, liver size and the extent of fatty infiltration. The hepatic drug metabolising capacity, as measured by total antipyrine clearance and the estimated total amount of cytochrome P-450, was at the same level as in non-diabetic control subjects with normal livers. Relative antipyrine clearance (per unit weight of liver) and cytochrome P-450 concentrations were significantly lower in the diabetics than in controls. The extent of fatty infiltration correlated poorly with the indices of drug metabolism. In non-insulin-dependent diabetics, slight to moderate hepatic fatty infiltration, without more serious structural distortion interfering with hepatic blood flow or hepatocellular function, seems to have only a minor influence on drug metabolism.

Evaluation of liver steatotic and fibrous content by computerized tomography and ultrasound

Twenty-four patients with steatotic liver underwent computerized tomography (CT) and ultrasound (US) examinations and liver biopsy, performed within a maximum interval of 6 weeks. The CT and US findings were compared with the fat and fibrous content of the biopsy specimens. A good linear inverse correlation between the CT findings and fat content was found. The ranges of CT values were 39-60 HU (mean, 52 HU) for mild fat content (less than or equal to 9.9%), 4-46 HU (mean, 27 HU) for moderate fat content (10.0-24.9%), and -6 to 19 HU (mean, 10 HU) for severe fat content (greater than or equal to 25.0%). With US it was possible to estimate roughly the fat and fibrous content of the liver. There was always the 'bright liver' finding in patients with 10.0% or more fat content, but it was impossible to estimate the content of fat more accurately. 'Bright liver' was also found in most patients with mildly and in all patients with severely increased fibrous content. It was impossible to differentiate the latter from each other or from the 'bright liver' caused by fatty degeneration.

Drug effects on the liver. An updated tabular compilation of drugs and drug-related hepatic diseases

Generic and chemical names of drugs and the possible adverse effects of these drugs on the human liver are tabulated. Most drugs compiled in these tables have been approved by the Federal Drug Administration. They are currently available in the United States, and they are listed in the 1983 Physicians' Desk Reference. Some important investigational drugs are listed also. The tables include: (1) generic names of drugs that have caused a characteristic morphologic change, such as granulomatous hepatitis; (2) morphologic diagnoses that have been documented after administration of each drug; and (3) references that can be matched to each drug and to its effects on the liver.

Medroxyprogesterone induced changes in rat liver. A light and electron microscopic study

Medroxyprogesterone acetate (MPA) induced morphological alterations in the normal female rat liver and after carbon tetrachloride exposure were assessed by light and electron microscopy and morphometry. Administration of MPA increased the smooth endoplasmic reticulum (SER) in normal rat. Carbon tetrachloride, injected intraperitoneally for four weeks, caused fatty accumulation, enlargement of the cell nucleus and decrease of the rough endoplasmic reticulum (RER) and increase of the SER. After one week of recovery, without treatment, the fatty infiltration and the SER membranes decreased and the RER increased. MPA, following injury, induced a decrease in the fatty accumulation and mitochondrial volume density and the hepatocyte nuclear and cytoplasm size normalized. The SER membrane volume density increased and the surface density decreased, the RER membrane volume density increased while the surface density did not alter significantly. The volume densities of the mitochondria and the peroxisomes decreased in the MPA treated CCl4 exposed groups. The results demonstrate that MPA induces a proliferation of the SER in normal rat liver and after hepatic injury the compound has a beneficial effect on the regeneration.

Histologic follow-up of alpha-methyldopa-induced liver injury

Alpha-methyldopa-induced liver injury was studied in six patients by clinical, biochemical, histologic, and morphometric methods. The patients, all women, developed hepatic injury after long-term therapy lasting 2 to 8 years. Withdrawal of the drug resulted in improvement of the symptoms. Hepatitis with fibrosis and moderate to severe fatty accumulation was seen in most of the liver biopsies at onset of symptoms. Follow-up ranged from 7 to 24.5 months, at the end of which the liver function test results were in the normal range. A second liver biopsy showed significant decrease in fatty infiltration. Three patients showed a decrease in lipid content from moderate to mild or normal and two other patients from severe to moderate. A 73-year-old patient had chronic aggressive hepatitis with massive necrosis of the parenchyma after 8 years of therapy, and follow-up biopsy 12 months later showed cirrhosis. In this study alpha-methyldopa withdrawal resulted in a reduction of lipid and fibrous trabeculae content, possibly caused by alpha-methyldopa-induced derangement of liver function.