Computerized Tomography Based Diagnosis of Visceral Obesity and Hepatic Steatosis is Associated with Low Urine pH.

PURPOSE: Uric acid nephrolithiasis is associated with an elevated visceral fat area in kidney stone formers. Hepatic steatosis has also been linked to visceral obesity and nephrolithiasis. We evaluated the association of noncontrast computerized tomography based diagnosis of visceral obesity and hepatic steatosis with 24-hour urine parameters and stone composition in kidney stone formers. MATERIALS AND METHODS: A total of 98 kidney stone formers were included in study who had computerized tomography imaging and 24-hour urine studies available. For each patient a single computerized tomography axial area measurement was obtained of the visceral fat area. Hepatic steatosis was diagnosed by comparing the HU of regions from the liver and spleen. Univariate analysis was performed to compare patients with or without an elevated visceral fat area and hepatic steatosis. Multivariate linear and logistic regression was done to assess for variables associated with 24-hour urine parameters and stone composition. RESULTS: An elevated visceral fat area was associated with higher 24-hour urine sodium (175 vs 157 mg per day, p <0.036) and lower 24-hour urine pH (5.724 vs 6.478, <0.0001). Urine pH less than 6 (OR 2.52) was associated with hepatic steatosis. Low urine pH less than 6 (OR 11.1, p = 0.004) and stone volume greater than 65 mm3 (OR 5.12, p = 0.023) were associated with an elevated visceral fat area. Low urine pH less than 6 (OR 5.87) and visceral fat area greater than 48% (OR 5.33) were associated with uric acid stones. Linear regression demonstrated that the percent of visceral fat area was associated with lower 24-hour urine pH (ß-coefficient -0.438, p <0.0001). CONCLUSIONS: Noncontrast computerized tomography based diagnosis of visceral obesity is associated with low urine pH, high urinary sodium and uric acid stone formation. Hepatic steatosis is associated with low urine pH.

Altered regulation of hepatic efflux transporters disrupts acetaminophen disposition in pediatric nonalcoholic steatohepatitis.

Nonalcoholic fatty liver disease (NAFLD) is the most common chronic liver disease, representing a spectrum of liver pathologies that include simple hepatic steatosis and the more advanced nonalcoholic steatohepatitis (NASH). The current study was conducted to determine whether pediatric NASH also results in altered disposition of acetaminophen (APAP) and its two primary metabolites, APAP-sulfate and APAP-glucuronide. Pediatric patients with hepatic steatosis (n = 9) or NASH (n = 3) and healthy patients (n = 12) were recruited in a small pilot study design. All patients received a single 1000-mg dose of APAP. Blood and urine samples were collected at 1, 2, and 4 hours postdose, and APAP and APAP metabolites were determined by high-performance liquid chromatography. Moreover, human liver tissues from patients diagnosed with various stages of NAFLD were acquired from the Liver Tissue Cell Distribution System to investigate the regulation of the membrane transporters, multidrug resistance-associated protein 2 and 3 (MRP2 and MRP3, respectively). Patients with the more severe disease (i.e., NASH) had increased serum and urinary levels of APAP-glucuronide along with decreased serum levels of APAP-sulfate. Moreover, an induction of hepatic MRP3 and altered canalicular localization of the biliary efflux transporter, MRP2, describes the likely mechanism for the observed increase in plasma retention of APAP-glucuronide, whereas altered regulation of sulfur activation genes may explain decreased sulfonation activity in NASH. APAP-glucuronide and APAP-sulfate disposition is altered in NASH and is likely due to hepatic membrane transporter dysregulation as well as altered intracellular sulfur activation.

Altered arsenic disposition in experimental nonalcoholic fatty liver disease.

Nonalcoholic fatty liver disease (NAFLD) is represented by a spectrum of liver pathologies ranging from simple steatosis to nonalcoholic steatohepatitis (NASH). Liver damage sustained in the progressive stages of NAFLD may alter the ability of the liver to properly metabolize and eliminate xenobiotics. The purpose of the current study was to determine whether NAFLD alters the disposition of the environmental toxicant arsenic. C57BL/6 mice were fed either a high-fat or a methionine-choline-deficient diet to model simple steatosis and NASH, respectively. At the conclusion of the dietary regimen, all mice were given a single oral dose of either sodium arsenate or arsenic trioxide. Mice with NASH excreted significantly higher levels of total arsenic in urine (24 h) compared with controls. Total arsenic in the liver and kidneys of NASH mice was not altered; however, NASH liver retained significantly higher levels of the monomethyl arsenic metabolite, whereas dimethyl arsenic was retained significantly less in the kidneys of NASH mice. NASH mice had significantly higher levels of the more toxic trivalent form in their urine, whereas the pentavalent form was preferentially retained in the liver of NASH mice. Moreover, hepatic protein expression of the arsenic biotransformation enzyme arsenic (3+ oxidation state) methyltransferase was not altered in NASH animals, whereas protein expression of the membrane transporter multidrug resistance-associated protein 1 was increased, implicating cellular transport rather than biotransformation as a possible mechanism. These results suggest that NASH alters the disposition of arsenical species, which may have significant implications on the overall toxicity associated with arsenic in NASH.

Urinary excretion of 5-hydroxy-3-indoleacetic acid in dystimic/depressed, adult obese women: what correlations to hepatic steatosis?

The synthesis of serotonin at CNS level is influenced by diet. Moreover, insulin resistance is associated with lower serotonin levels. Visceral obesity, strictly linked to hepatic steatosis is specifically associated with mild to severe somatic affective-depressive symptom clusters. Previous data support the view that depression involves serotonergic systems, reflecting low levels of urinary 5- hydroxy-3-indoleacetic acid (5-HIAA). The 24-h urinary excretion of 5-HIAA was evaluated in 76 dystimic/depressed, obese/overweight females, divided into two groups, i.e., on a hyper-caloric diet, associated with a life style characterized by leisure time sedentary behavior (LTSB, 35 women), or on a normo-caloric diet, assisted by program-based strategies aimed at promoting physical activity participation (PAP, 41 women). Beck Depression Inventory (BDI) was carried out to score the severity of dystimia/depression. Anthropometric measures, metabolic indices, severity of hepatic steatosis at sonography and HOMA were studied. Urinary levels of 5-HIAA in controls and PAP groups were comparable with a great overlap, while in the LTSB group the urinary excretion of 5-HIAA was significantly reduced in respect to that of the PAP group and obviously compared to that of the control group, 3.4±1.4 mg/L versus 6.2±2.7 mg/L and 6.4±2.6 mg/L, respectively, ANOVA test, P= 0.001. Among metabolic indices, cholesterol, HDL-cholesterol, triglycerides and uric acid were not able to predict urinary concentrations of 5-HIAA, which were not associated with hepatic steatosis; vice versa, ferritin levels, and mainly HOMA values, were independent predictors of the urinary excretion of 5-HIAA (ß=0.235 and 0.45, respectively). Dystimia/depression severity was negatively predicted by urinary 5-HIAA levels in the sense that the highest BDI values were forecast by the lowest values of urinary 5-HIAA (ß= -0.72).The importance of measuring the 24-h urinary excretion of 5-HIAA in follow-ups could rely on a method simultaneously mirroring the well-being status, the adherence to physical activity, which leads to improved insulin sensitivity, and the eating habits acquired by dystimic/depressed overweight/obese patients. In contrast, the significance of the urinary 5-HIAA is reduced in evaluating the severity of hepatic steatosis, likely because it is a structured process.

A Metabolomic Study on the Intervention of Traditional Chinese Medicine Qushi Huayu Decoction on Rat Model of Fatty Liver Induced by High-Fat Diet.

Qushi Huayu Decoction (QHD), an important clinically proved herbal formula, has been reported to be effective in treating fatty liver induced by high-fat diet in rats. However, the mechanism of action has not been clarified at the metabolic level. In this study, a urinary metabolomic method based on gas chromatography-mass spectrometry (GC-MS) coupled with pattern recognition analysis was performed in three groups (control, model, and QHD group), to explore the effect of QHD on fatty liver and its mechanism of action. There was obvious separation between the model group and control group, and the QHD group showed a tendency of recovering to the control group in metabolic profiles. Twelve candidate biomarkers were identified and used to explore the possible mechanism. Then, a pathway analysis was performed using MetaboAnalyst 3.0 to illustrate the pathways of therapeutic action of QHD. QHD reversed the urinary metabolite abnormalities (tryptophan, uridine, and phenylalanine, etc.). Fatty liver might be prevented by QHD through regulating the dysfunctions of phenylalanine, tyrosine, and tryptophan biosynthesis, phenylalanine metabolism, and tryptophan metabolism. This work demonstrated that metabolomics might be helpful for understanding the mechanism of action of traditional Chinese medicine for future clinical evaluation.

Serum resistin and hepatic fat content in nondiabetic individuals.

CONTEXT: Serum resistin concentration is increased in patients with nonalcoholic fatty liver disease in proportion with the histological severity of the disease, but the relevance of the contribution of fatty liver per se is undetermined. OBJECTIVE: The objective of the study was to assess the relationship between serum resistin and the degree of ectopic fat accumulation in vivo in humans. DESIGN AND SETTING: The hepatic fat (IHF) content, measured quantitatively by means of 1H magnetic resonance spectroscopy, serum resistin, and biochemical and hormonal metabolic correlates of fatty liver and insulin resistance were assessed in 28 affected patients, and 47 individuals with comparable anthropometric features served as controls. Insulin sensitivity was estimated using the computer homeostatic model assessment (HOMA)-2. A subset of volunteers (n = 18) also underwent 1H magnetic resonance spectroscopy of the calf muscles to assess the intramyocellular lipid content (IMCL). RESULTS: In patients with fatty liver, the IHF content (13 +/- 8 vs. 2 +/- 1% wet weight; P < 0.0001) and also the soleus IMCL content (P < 0.05) were increased in comparison with the controls. Patients with fatty liver had lower insulin sensitivity (HOMA2 insulin sensitivity: 59 +/- 24 vs. 72 +/- 29%; P < 0.04), serum resistin (3.4 +/- 0.8 vs. 3.9 +/- 1.0 ng/ml; P < 0.02), and adiponectin (P < 0.01) concentrations. Serum resistin was inversely correlated with the IHF content (r = -0.35; P < 0.003) and the soleus IMCL content (r = -0.51; P < 0.05) but not HOMA2 insulin sensitivity. CONCLUSION: This study demonstrates that excessive ectopic fat accumulation in the liver and skeletal muscle of insulin-resistant subjects is associated with lower serum resistin concentration and not with hyperresistinemia.

[Factors affecting the increase of urinary diacetylspermine levels : a study in patients with liver diseases].

Recently, diacetylspermine was identified in urine and several groups have reported its clinical significance as a tumor marker. However, abnormally high values of urinary diacetylspermine are found in not a few cases with benign diseases. In order to seek which factors influence its urinary levels, we analyzed the levels in patients with various liver diseases. Our results indicate that viral amount, steroid hormones, and low calorie diet may be responsible factors to increase the levels. When we interpret the data of urinary diacetylspermine in patients, it is needed to consider whether these factors exist in the patients.

Elevated urine neopterin levels in nonalcoholic steatohepatitis.

OBJECTIVES: The aim of this study was to relate urine levels of neopterin, a marker of activation of the cellular immune system, with grading and staging of NASH. DESIGN AND METHODS: Urine concentrations of neopterin, routine tests, insulin and C-peptide levels were assessed in 50 patients with NASH, 25 patients with chronic viral hepatitis (CVH), and in 26 healthy controls. RESULTS: Urine neopterin levels were found elevated in the NASH and CVH groups compared with controls. There was no significant correlation between urine neopterin levels and inflammation grade in the liver. CONCLUSIONS: Urine neopterin levels are a marker of cellular immunity and are higher in patients with NASH. However, neopterin levels were not significantly associated with histopathological grade and stage of disease.

Effects of Fatty Liver Induced by Excess Orotic Acid on B-Group Vitamin Concentrations of Liver, Blood, and Urine in Rats.

Fatty liver is caused when rats are given orotic acid of the pyrimidine base in large quantities. The lack of B-group vitamins suppresses the biosynthesis of fatty acids. We investigated how orotic acid-induced fatty liver affects the concentrations of liver, blood, and urine B-group vitamins in rats. The vitamin B6 and B12 concentrations of liver, blood, and urine were not affected by orotic acid-induced fatty liver. Vitamin B2 was measured only in the urine, but was unchanged. The liver, blood, and urine concentrations of niacin and its metabolites fell dramatically. Niacin and its metabolites in the liver, blood, and urine were affected as expected. Although the concentrations of vitamin B1, pantothenic acid, folate, and biotin in liver and blood were decreased by orotic acid-induced fatty liver, these urinary excretion amounts showed a specific pattern toward increase. Generally, as for the typical urinary excretion of B-group vitamins, these are excreted when the body is saturated. However, the ability to sustain vitamin B1, pantothenic acid, folate, and biotin decreased in fatty liver, which is hypothesized as a specific phenomenon. This metabolic response might occur to prevent an abnormally increased biosynthesis of fatty acids by orotic acid.

3 alpha-Hydroxylated bile acid profiles in clinically normal cats, cats with severe hepatic lipidosis, and cats with complete extrahepatic bile duct occlusion.

Concentrations of 3 alpha-hydroxylated bile acids were measured in serum and urine of clinically normal (healthy) cats (n = 6), cats with severe hepatic lipidosis (n = 9), and cats with complete bile duct occlusion (n = 4). Bile acid concentrations were measured by use of a gradient flow high-performance liquid chromatography procedure with an acetonitrile and ammonium phosphate mobile phase and an in-line postanalytic column containing 3 alpha-hydroxy-steroid dehydrogenase and a fluorescence detector. Specific identification of all bile acid peaks was not completed; unidentified moieties were represented in terms of their elution time (in minutes). Significant differences in serum and urine bile acid concentrations, quantitative and proportional, were determined among groups of cats. Cats with hepatic lipidosis and bile duct occlusion had significantly (P > or = 0.05) greater total serum and urine bile acids concentrations than did healthy cats. The proportion of hydrophobic bile acids in serum, those eluting at > or = 400 minutes, was 1.9% for healthy cats, 3.3% for cats with lipidosis, and 5.4% for bile duct-obstructed cats. Both groups of ill cats had a broader spectrum of unidentified late-eluting serum bile acids than did healthy cats; the largest spectrum developed in bile duct-occluded cats.(ABSTRACT TRUNCATED AT 250 WORDS)

Urinary orotic acid-to-creatinine ratios in cats with hepatic lipidosis.

OBJECTIVE: To determine urinary orotic acid (OA) concentration and evaluate the urinary OA-to-creatinine ratio (OACR) in cats with hepatic lipidosis (HL). ANIMALS: 20 cats with HL and 20 clinically normal cats. PROCEDURE: Hepatic lipidosis was diagnosed on the basis of clinical signs, results of serum biochemical analyses, exclusion of other concurrent illness, and cytologic or histologic evaluation of liver biopsy specimens. Urine samples were collected from each cat and frozen at -20 C until assayed. Urine creatinine concentrations were determined, using an alkaline picrate method followed by spectrophotometric assay. Urine OA concentration was determined, using high-performance liquid chromatography. Minimum amount of detectable OA in feline urine was 1 microg/ml. Because of small interfering peaks near the base of the OA peak, the minimum quantifiable concentration of OA was determined to be 5 microg/ml. Urinary OACR was compared in both groups of cats. RESULTS: Differences in urinary OACR were not detected between clinically normal cats and cats with HL. Peaks were not detected for urinary OA in any of the 20 clinically normal cats. Of the 20 HL cats, 14 did not have detectable peaks for urinary OA. Of the 6 HL cats that had detectable urinary OA peaks, 3 had values of <5 microg/ml. CONCLUSIONS: Apparently, OACR does not increase significantly in cats with HL. CLINICAL RELEVANCE: Urinary OACR is not a useful diagnostic test for HL in cats.

[Polyuria and polydipsia in acute fatty liver of pregnancy. Discussion based on a case]. / Polyuro-polydipsie et stéatose hépatique aiguë gravidique. Discussion à propos d'un cas.

We report the case of a 25-year-old nullipara in whom polyuria and polydipsia occurred 8 weeks before the first symptoms of acute fatty liver of pregnancy and disappeared a few days after delivery. This time course suggests that polyuria and polydipsia were closely related to acute fatty liver of pregnancy. Thus, this diagnosis should be envisaged in any woman with normal blood levels of glucose and calcium, and complaining of polyuria and polydipsia in the third trimester of pregnancy.

[Xanthurenuria at different stages of liver lesion induced by protein and choline deficiency]. / Izuchenie ksanturenurii na razlichnykh stadiiakh povrezhdeniia pecheni, vyzbannogo defitsitom belka i kholina.

The parallelism between xanthurenuria and liver affections caused by protein and choline deficiency was studied. At the stages marking the development of lipohepatosis and fibrosis there occurred an intensive passage of xanthurenic acid. The intensity of xanthurenuria at the stage marking the appearance of hyperplastic nodes continued to gain strength. With progressive advance of pathological changes, which by the 9--12th months of the experiment reached the stage of a fully developed nodular cirrhosis xanthurenuria gradually stopped.

Cigarette smoke toxins deposited on surfaces: implications for human health.

Cigarette smoking remains a significant health threat for smokers and nonsmokers alike. Secondhand smoke (SHS) is intrinsically more toxic than directly inhaled smoke. Recently, a new threat has been discovered - Thirdhand smoke (THS) - the accumulation of SHS on surfaces that ages with time, becoming progressively more toxic. THS is a potential health threat to children, spouses of smokers and workers in environments where smoking is or has been allowed. The goal of this study is to investigate the effects of THS on liver, lung, skin healing, and behavior, using an animal model exposed to THS under conditions that mimic exposure of humans. THS-exposed mice show alterations in multiple organ systems and excrete levels of NNAL (a tobacco-specific carcinogen biomarker) similar to those found in children exposed to SHS (and consequently to THS). In liver, THS leads to increased lipid levels and non-alcoholic fatty liver disease, a precursor to cirrhosis and cancer and a potential contributor to cardiovascular disease. In lung, THS stimulates excess collagen production and high levels of inflammatory cytokines, suggesting propensity for fibrosis with implications for inflammation-induced diseases such as chronic obstructive pulmonary disease and asthma. In wounded skin, healing in THS-exposed mice has many characteristics of the poor healing of surgical incisions observed in human smokers. Lastly, behavioral tests show that THS-exposed mice become hyperactive. The latter data, combined with emerging associated behavioral problems in children exposed to SHS/THS, suggest that, with prolonged exposure, they may be at significant risk for developing more severe neurological disorders. These results provide a basis for studies on the toxic effects of THS in humans and inform potential regulatory policies to prevent involuntary exposure to THS.

A switch in hepatic cortisol metabolism across the spectrum of non alcoholic fatty liver disease.

CONTEXT: Non alcoholic fatty liver disease (NAFLD) is the hepatic manifestation of the metabolic syndrome. NAFLD represents a spectrum of liver disease ranging from reversible hepatic steatosis, to non alcoholic steato-hepatitis (NASH) and cirrhosis. The potential role of glucocorticoids (GC) in the pathogenesis of NAFLD is highlighted in patients with GC excess, Cushing's syndrome, who develop central adiposity, insulin resistance and in 20% of cases, NAFLD. Although in most cases of NAFLD, circulating cortisol levels are normal, hepatic cortisol availability is controlled by enzymes that regenerate cortisol (F) from inactive cortisone (E) (11ß-hydroxysteroid dehydrogenase type 1, 11ß-HSD1), or inactivate cortisol through A-ring metabolism (5α- and 5ß-reductase, 5αR and 5ßR). OBJECTIVE AND METHODS: In vitro studies defined 11ß-HSD1 expression in normal and NASH liver samples. We then characterised hepatic cortisol metabolism in 16 patients with histologically proven NAFLD compared to 32 obese controls using gas chromatographic analysis of 24 hour urine collection and plasma cortisol generation profile following oral cortisone. RESULTS: In patients with steatosis 5αR activity was increased, with a decrease in hepatic 11ß-HSD1 activity. Total cortisol metabolites were increased in this group consistent with increased GC production rate. In contrast, in patients with NASH, 11ß-HSD1 activity was increased both in comparison to patients with steatosis, and controls. Endorsing these findings, 11ß-HSD1 mRNA and immunostaining was markedly increased in NASH patients in peri septal hepatocytes and within CD68 positive macrophages within inflamed cirrhotic septa. CONCLUSION: Patients with hepatic steatosis have increased clearance and decreased hepatic regeneration of cortisol and we propose that this may represent a protective mechanism to decrease local GC availability to preserve hepatic metabolic phenotype. With progression to NASH, increased 11ß-HSD1 activity and consequent cortisol regeneration may serve to limit hepatic inflammation.

Lung-dominant connective tissue disease among patients with interstitial lung disease: prevalence, functional stability, and common extrathoracic features / Colagenose pulmão dominante em pacientes com doença pulmonar intersticial: prevalência, estabilidade funcional e manifestações extratorácicas comuns

OBJECTIVE: To describe the characteristics of a cohort of patients with lung-dominant connective tissue disease (LD-CTD). METHODS: This was a retrospective study of patients with interstitial lung disease (ILD), positive antinuclear antibody (ANA) results (≥ 1/320), with or without specific autoantibodies, and at least one clinical feature suggestive of connective tissue disease (CTD). RESULTS: Of the 1,998 patients screened, 52 initially met the criteria for a diagnosis of LD-CTD: 37% were male; the mean age at diagnosis was 56 years; and the median follow-up period was 48 months. During follow-up, 8 patients met the criteria for a definitive diagnosis of a CTD. The remaining 44 patients comprised the LD-CTD group, in which the most prevalent extrathoracic features were arthralgia, gastroesophageal reflux disease, and Raynaud's phenomenon. The most prevalent autoantibodies in this group were ANA (89%) and anti-SSA (anti-Ro, 27%). The mean baseline and final FVC was 69.5% and 74.0% of the predicted values, respectively (p > 0.05). Nonspecific interstitial pneumonia and usual interstitial pneumonia patterns were found in 45% and 9% of HRCT scans, respectively; 36% of the scans were unclassifiable. A similar prevalence was noted in histological samples. Diffuse esophageal dilatation was identified in 52% of HRCT scans. Nailfold capillaroscopy was performed in 22 patients; 17 showed a scleroderma pattern. CONCLUSIONS: In our LD-CTD group, there was predominance of females and the patients showed mild spirometric abnormalities at diagnosis, with differing underlying ILD patterns that were mostly unclassifiable on HRCT and by histology. We found functional stability on follow-up. Esophageal dilatation on HRCT and scleroderma pattern on nailfold capillaroscopy were frequent findings and might come to serve as diagnostic criteria. .

OBJETIVO: Descrever as características de uma coorte de pacientes com colagenose pulmão dominante (CPD). MÉTODOS: Estudo retrospectivo de pacientes com doença pulmonar intersticial (DPI), anticorpo antinuclear (ANA) positivo (≥ 1/320), com ou sem autoanticorpos específicos, e com a presença de ao menos uma manifestação clínica sugestiva de doença do tecido conjuntivo (DTC). RESULTADOS: Dos 1.998 avaliados, 52 preencheram inicialmente os critérios para o diagnóstico de CPD: 37% eram homens; a média de idade ao diagnóstico era de 56 anos e a mediana do tempo de seguimento era de 48 meses. Durante o seguimento, 8 pacientes preencheram os critérios para um diagnóstico definitivo de DTC. Os 44 pacientes restantes formaram o grupo CPD, no qual as manifestações extratorácicas mais prevalentes foram artralgia, doença do refluxo gastroesofágico e fenômeno de Raynaud. Os autoanticorpos mais prevalentes nesse grupo foram ANA (89%) e anti-SSA (anti-Ro, 27%). A média de CVF no início e na última avaliação foi de 69,5% e 74,0% do predito, respectivamente (p > 0,05). Pneumonia intersticial não específica e pneumonia intersticial usual foram identificadas em 45% e 9% das TCARs, respectivamente; 36% das TCARs eram não classificáveis. Uma prevalência semelhante foi identificada na histologia. Dilatação esofágica difusa foi identificada em 52% das TCARs. Capilaroscopia subungueal foi realizada em 22 pacientes; 17 apresentavam um padrão de esclerodermia. CONCLUSÕES: No grupo CPD, houve predominância feminina, e os pacientes apresentaram alterações espirométricas leves ao diagnóstico, com diferentes padrões de DPI, em sua maioria não classificáveis, tanto em TCAR como na histologia. Estabilidade funcional foi identificada no seguimento. A dilatação esofágica em TCAR e o padrão de esclerodermia na capilaroscopia subungueal foram achados frequentes que poderiam servir como critérios diagnósticos. .

A comparative study of urinary xanthopterin and neopterin in liver diseases.

By adsorption to activated charcoal, various pteridine derivatives in human urine are oxidized to xanthopterin. Following this oxidation, xanthopterin in urine from healthy subjects and from patients with liver diseases was assayed by high performance liquid chromatography. The mean values for xanthopterin in healthy subjects were 532 +/- 116 mumol/mol creatinine (mean +/- SD) in males and 585 +/- 153 mumol/mol creatinine in females; the difference was statistically significant (p < 0.01). Xanthopterin concentrations in patients with liver disease were significantly higher than those in normal subjects. When compared with urinary neopterin, which is a marker of activated cell immunity, xanthopterin was significantly increased even in fatty liver disease. These findings suggest that increased concentrations of urinary xanthopterin in liver diseases reflect not only the status of activated cell-mediated immunity, but also injury to liver cells.