May circulating steroids reveal a predisposition to intrahepatic cholestasis of pregnancy in non-pregnant women?

Intrahepatic cholestasis of pregnancy (ICP) is a frequent liver disorder, mostly occurring in the third trimester. ICP is not harmful to the mothers but threatens the fetus. The authors evaluated steroid alterations in maternal and mixed umbilical blood to elucidate their role in the ICP development. Ten women with ICP were included in the study. Steroids in the maternal blood were measured by Gas Chromatography-Mass Spectrometry (GC-MS) (n=58) and RIA (n=5) at the diagnosis of ICP, labor, day 5 postpartum, week 3 postpartum and week 6 postpartum. The results were evaluated by ANOVA consisting of the subject factor, between subject factors ICP, gestational age at the diagnosis of ICP and gestational age at labor, within-subject factor Stage and ICP × Stage interaction. The 17 controls were firstly examined in the week 36 of gestation. ICP patients showed reduced CYP17A1 activity in the C17,20 lyase step thus shifting the balance between the toxic conjugated pregnanediols and harmless sulfated 5alpha/beta-reduced-17-oxo C19 steroids. Hence, more toxic metabolites originating in maternal liver from the placental pregnanes may penetrate backward to the fetal circulation. As these alterations persist in puerperium, the circulating steroids could be potentially used for predicting the predisposition to ICP even before next pregnancy.

Neuro-inflammatory effects of photodegradative products of bilirubin.

Phototherapy was introduced in the early 1950's, and is the primary treatment of severe neonatal jaundice or Crigler-Najjar syndrome. Nevertheless, the potential biological effects of the products generated from the photodegradation of bilirubin during phototherapy remain unknown. This is very relevant in light of recent clinical observations demonstrating that the use of aggressive phototherapy can increase morbidity or even mortality, in extremely low birthweight (ELBW) infants. The aim of our study was to investigate the effects of bilirubin, lumirubin (LR, its major photo-oxidative product), and BOX A and B (its monopyrrolic oxidative products) on the central nervous system (CNS) using in vitro and ex vivo experimental models. The effects of bilirubin photoproducts on cell viability and expression of selected genes were tested in human fibroblasts, three human CNS cell lines (neuroblastoma SH-SY5Y, microglial HMC3, and glioblastoma U-87 cell lines), and organotypic rat hippocampal slices. Neither bilirubin nor its photo-oxidative products affected cell viability in any of our models. In contrast, LR in biologically-relevant concentrations (25 µM) significantly increased gene expression of several pro-inflammatory genes as well as production of TNF-α in organotypic rat hippocampal slices. These findings might underlie the adverse outcomes observed in ELBW infants undergoing aggressive phototherapy.

Bilirubin and atherosclerotic diseases.

Bilirubin is the final product of heme catabolism in the systemic circulation. For decades, increased serum/plasma bilirubin levels were considered an ominous sign of an underlying liver disease. However, data from recent years convincingly suggest that mildly elevated bilirubin concentrations are associated with protection against various oxidative stress-mediated diseases, atherosclerotic conditions being the most clinically relevant. Although scarce data on beneficial effects of bilirubin had been published also in the past, it took until 1994 when the first clinical study demonstrated an increased risk of coronary heart disease in subjects with low serum bilirubin levels, and bilirubin was found to be a risk factor for atherosclerotic diseases independent of standard risk factors. Consistent with these results, we proved in our own studies, that subjects with mild elevation of serum levels of unconjugated bilirubin (benign hyperbilirubinemia, Gilbert syndrome) have much lower prevalence/incidence of coronary heart as well as peripheral vascular disease. We have also demonstrated that this association is even more general, with serum bilirubin being a biomarker of numerous other diseases, often associated with increased risk of atherosclerosis. In addition, very recent data have demonstrated biological pathways modulated by bilirubin, which are responsible for observed strong clinical associations.

Background levels of neomorphic 2-hydroxyglutarate facilitate proliferation of primary fibroblasts.

Each cell types or tissues contain certain "physiological" levels of R-2-hydroxyglutarate (2HG), as well as enzymes for its synthesis and degradation. 2HG accumulates in certain tumors, possessing heterozygous point mutations of isocitrate dehydrogenases IDH1 (cytosolic) or IDH2 (mitochondrial) and contributes to strengthening their malignancy by inhibiting 2-oxoglutarate-dependent dioxygenases. By blocking histone de-methylation and 5-methyl-cytosine hydroxylation, 2HG maintains cancer cells de-differentiated and promotes their proliferation. However, physiological 2HG formation and formation by non-mutant IDH1/2 in cancer cells were neglected. Consequently, low levels of 2HG might play certain physiological roles. We aimed to elucidate this issue and found that compared to highest 2HG levels in hepatocellular carcinoma HepG2 cells and moderate levels in neuroblastoma SH-SY5Y cells, rat primary fibroblast contained low basal 2HG levels at early passages. These levels increased at late passage and likewise 2HG/2OG ratios dropped without growth factors and enormously increased at hypoxia, reaching levels compared to cancer HepG2 cells. Responses in SH-SY5Y cells were opposite. Moreover, external 2HG supplementation enhanced fibroblast growth. Hence, we conclude that low 2HG levels facilitate cell proliferation in primary fibroblasts, acting via hypoxia-induced factor regulations and epigenetic changes.

Changes in Liver Ganglioside Metabolism in Obstructive Cholestasis - the Role of Oxidative Stress.

Bile acids have been implicated in cholestatic liver damage, primarily due to their detergent effect on membranes and induction of oxidative stress. Gangliosides can counteract these harmful effects by increasing the rigidity of the cytoplasmic membrane. Induction of haem oxygenase (HMOX) has been shown to protect the liver from increased oxidative stress. The aim of this study was to determine the changes in the synthesis and distribution of liver gangliosides following bile duct ligation (BDL), and to assess the effects of HMOX both on cholestatic liver injury and ganglioside metabolism. Compared to controls, BDL resulted in a significant increase in total as well as complex gangliosides and mRNA expression of corresponding glycosyltransferases ST3GalV, ST8SiaI and B3GalTIV. A marked shift of GM1 ganglioside from the intracellular compartment to the cytoplasmic membrane was observed following BDL. Induction of oxidative stress by HMOX inhibition resulted in a further increase of these changes, while HMOX induction prevented this effect. Compared to BDL alone, HMOX inhibition in combination with BDL significantly increased the amount of bile infarcts, while HMOX activation decreased ductular proliferation. We have demonstrated that cholestasis is accompanied by significant changes in the distribution and synthesis of liver gangliosides. HMOX induction results in attenuation of the cholestatic pattern of liver gangliosides, while HMOX inhibition leads to the opposite effect.

The effect of colesevelam treatment on bile acid and lipid metabolism and glycemic control in healthy men.

The treatment of hypercholesterolemia with bile acid (BA) sequestrants results in upregulation of BA synthesis through the classical pathway initiated by cholesterol 7alpha-hydroxylase (CYP7A1). To characterize the detailed dynamics of serum lipid and BA concentrations and the BA synthesis rate in response to treatment with BA sequestrants and to determine whether the -203A/C promoter polymorphism of the CYP7A1 encoding gene (CYP7A1) affects such a response, this pilot study was carried out in healthy men (8 homozygous for the -203A allele and 8 homozygous for the -203C allele of CYP7A1). The subjects were treated for 28 days with colesevelam and blood was drawn for analysis before and on days 1, 3, 7, 14 and 28 of treatment. The response of lipids, BA, fibroblast growth factor-19 (FGF19) and 7alpha-hydroxy-4-cholesten-3-one (C4) to colesevelam did not differ between carriers of -203A and -203C alleles; their data were then aggregated for further analysis. Colesevelam treatment caused immediate suppression of FGF19 concentration and a fivefold increase in CYP7A1 activity, as assessed from C4 concentration, followed by a 17 % decrease in LDL-cholesterol. Although total plasma BA concentrations were not affected, the ratio of cholic acid/total BA rose from 0.25+/-0.10 to 0.44+/-0.16 during treatment at the expense of decreases in chenodeoxycholic and deoxycholic acid.

Heme oxygenase is not involved in the anti-proliferative effects of statins on pancreatic cancer cells.

BACKGROUND: Pancreatic cancer is recognized as one of the most fatal tumors due to its aggressiveness and resistance to therapy. Statins were previously shown to inhibit the proliferation of cancer cells via various signaling pathways. In healthy tissues, statins activate the heme oxygenase pathway, nevertheless the role of heme oxygenase in pancreatic cancer is still controversial. The aim of this study was to evaluate, whether anti-proliferative effects of statins in pancreatic cancer cells are mediated via the heme oxygenase pathway. METHODS: In vitro effects of various statins and hemin, a heme oxygenase inducer, on cell proliferation were evaluated in PA-TU-8902, MiaPaCa-2 and BxPC-3 human pancreatic cancer cell lines. The effect of statins on heme oxygenase activity was assessed and heme oxygenase-silenced cells were used for pancreatic cancer cell proliferation studies. Cell death rate and reactive oxygen species production were measured in PA-TU-8902 cells, followed by evaluation of the effect of cerivastatin on GFP-K-Ras trafficking and expression of markers of invasiveness, osteopontin (SPP1) and SOX2. RESULTS: While simvastatin and cerivastatin displayed major anti-proliferative properties in all cell lines tested, pravastatin did not affect the cell growth at all. Strong anti-proliferative effect was observed also for hemin. Co-treatment of cerivastatin and hemin increased anti-proliferative potential of these agents, via increased production of reactive oxygen species and cell death compared to individual treatment. Heme oxygenase silencing did not prevent pancreatic cancer cells from the tumor-suppressive effect of cerivastatin or hemin. Cerivastatin, but not pravastatin, protected Ras protein from trafficking to the cell membrane and significantly reduced expressions of SPP1 (p < 0.05) and SOX2 (p < 0.01). CONCLUSIONS: Anti-proliferative effects of statins and hemin on human pancreatic cancer cell lines do not seem to be related to the heme oxygenase pathway. While hemin triggers reactive oxygen species-induced cell death, cerivastatin targets Ras protein trafficking and affects markers of invasiveness.

Gene variants at FTO, 9p21, and 2q36.3 are age-independently associated with myocardial infarction in Czech men.

AIM: Cardiovascular disease (CVD) is a major cause of morbidity and mortality in developed countries. This study aimed to confirm the effect of common putative CVD-associated gene variants (FTO rs17817449, KIF6 rs20455, 9p21 rs10757274 and 2q36.3 rs2943634) on CVD manifestation, and determine whether this effect differs between younger (< 50 years) and older CVD patients. METHODS: 1191 controls and 1889 MI patients were analyzed. All participants were Caucasian Czech males aged <65 years (532 were <50 years) who were examined at cardiology clinics in Prague, Czech Republic. Variants of FTO, 9p21, 2q36.3, and KIF-6 were genotyped using PCR-RFLP or TaqMan assay. RESULTS: Variants of FTO (OR 1.48; 95% CI, 1.19-1.84 in a TT vs. GG comparison, p=0.0005); 9p21 (OR 1.74; 95% CI, 1.41-2.14 in an AA vs. GG comparison, p=0.0001); and 2q36.3 (OR 1.34; 95%CI, 1.09-1.65 in an AA vs. +C comparison, p=0.006) were significantly associated with MI in the male Czech population. In contrast, genotype frequencies of KIF-6 (rs20455) were the same in patients and controls (P=1.00). Nearly identical results were observed when a subset of young MI patients (N=532, aged <50 years) was analyzed. CONCLUSION: We confirmed the importance of determining FTO, 9p21, and 2q36.3 variants as part of the genetic determination of MI risk in the Czech male population.

The role of steroid hormones in the development of intrahepatic cholestasis of pregnancy.

Intrahepatic cholestasis of pregnancy (ICP) is a disorder of liver function, commonly occurring in the third trimester but sometimes also as soon as the end of the second trimester of pregnancy. Symptoms of this disorder include pruritus, plus abnormal values of bile acids and hepatic transaminases. After birth, symptoms disappear and liver function returns to normal. Though ICP is relatively non-complicated and often symptomatically mild from the point-of-view of the mother, it presents a serious risk to the fetus, making this disease the subject of great interest. The etiology and pathogenesis of ICP is multifactorial and as yet not fully elucidated. Hormonal factors likely play a significant role, along with genetic as well as exogenous factors. Here we summarize the knowledge of changes in steroid hormones and their role in the development of intrahepatic cholestasis of pregnancy. In addition, we consider the role of exogenous factors as possible triggers of steroid hormone changes, the relationship between metabolic steroids and bile acids, as well as the combination of these factors in the development of ICP in predisposed pregnant women.

Two cases of spuriously elevated cerebrospinal glucose concentration.

We present two cases of spuriously high cerebrospinal fluid glucose concentration with approximately normal blood glucose concentrations. The cause of these abnormal findings was the use of inappropriate collection tubes during the pre-analytical phase. Whilst no patient harm was identified following this error, significant time and effort were expended by both laboratory and clinical staff to explain the cause of these findings.

The effect of heme oxygenase on ganglioside redistribution within hepatocytes in experimental estrogen-induced cholestasis.

Cholestasis is characterized by the elevation of serum total bile acids (TBA), which leads to the production of both free radicals and oxidative stress. Although they do not share the same mechanisms, membrane glycosphingolipids (GSL) and the antioxidant enzyme heme oxygenase-1 (HMOX1) both act against the pro-oxidative effect of TBA. The aim of the study was to assess the role of HMOX on GSL redistribution and composition within hepatocytes in the rat model of estrogen-induced cholestasis. Compared to the controls, an increase of total gangliosides in the liver homogenates of the cholestatic group (P=0.001) was detected; further, it paralleled along with the activation of their biosynthetic b-branch pathway (P<0.01). These effects were partially prevented by HMOX activation. Cholestasis was accompanied by a redistribution of GM1 ganglioside from the cytoplasm to the sinusoids; while HMOX activation led to the retention of GM1 in the cytoplasm (P=0.014). Our study shows that estrogen-induced cholestasis is followed by changes in the synthesis and/or distribution of GSL. These changes are not only triggered by the detergent power of accumulated TBA, but also by their pro-oxidant action. Increases in the antioxidant defenses might represent an important supportive therapeutic measure for patients with cholestatic liver disease.

Protective effects of inhaled carbon monoxide in endotoxin-induced cholestasis is dependent on its kinetics.

Carbon monoxide (CO), a product of heme oxygenase (HMOX), has many beneficial biological functions and is a promising therapeutic agent for many pathological conditions. However, the kinetics of inhaled CO and its protective role in endotoxin-induced cholestasis is not fully known. Thus, our objective was to characterize the kinetics of inhaled CO and then investigate its use in early phase experimental endotoxin-induced cholestasis. Female Wistar rats were randomly divided into 4 groups: CON (control), LPS (lipopolysaccharide, 6 mg/kg), CO (250 ppm COx1h), and CO + LPS. Rats were sacrificed at 0-12 h after LPS administration. Tissues and blood were collected for liver injury markers and tissue CO distribution measurements. Livers were harvested for measurements of Hmox activity, Hmox1 mRNA expression, cytokines (IL10, IL6, TNF), and bile lipid and pigment transporters. Half-lives of CO in spleen, blood, heart, brain, kidney, liver, and lungs were 2.4 ± 1.5, 2.3 ± 0.8, 1.8 ± 1.6, 1.5 ± 1.2, 1.1 ± 1.1, 0.6 ± 0.3, 0.6 ± 0.2 h, respectively. CO treatment increased liver IL10 mRNA and decreased TNF expression 1 h after LPS treatment and prevented the down-regulation of bile acid and bilirubin hepatic transporters (Slc10a1, Abcb11, and Abcc2, p < 0.05), an effect closely related to the kinetics. The protective effect of CO against cholestatic liver injury persisted even 12 h after CO exposure, as shown by attenuation of serum cholestatic markers in CO-treated animals. CO exposure substantially attenuated endotoxin-induced cholestatic liver injury and was directly related to the kinetics of inhaled CO. This data underscores the importance of the kinetics of inhaled CO for the proper design of experimental and clinical studies of using CO as a treatment strategy.

[Relationship of bilirubin to diseases caused by increased oxidative stress]. / Vztah bilirubinu k nemocem vyvolaným zvýseným oxidacním stresem.

Oxidative stress contributes importantly to pathogenesis of numerous civilization diseases, including cardiovascular diseases, cancer, as well as autoimmune and neurodegenerative conditions. Bilirubin is the major product of the heme catabolic pathway in the intravascular compartment. For long time, bilirubin was considered to be only a waste product, however, recent data from the last 2 decades have proved its important antioxidant properties, which contributes to defense against increased oxidative stress. Numerous experimental as well as clinical studies have demonstrated association between low bilirubin concentrations and cardiovascular diseases, diabetes, certain cancers, autoimunne diseases, such as lupus erythematodes, or rheumatoid arthritis or neurological psychiatric disorders, such as schizofrenia. On the other hand, subjects with mildly elevated blood bilirubin levels, typical for Gilbert syndrome, have decreased risk of these diseases.

[Intrahepatic cholestasis of pregnancy]. / Intrahepatální cholestáza v tehotenství

The review of intrahepatic cholestasis of pregnancy attempts to summarize the current knowledge of this disease by analysing available literary sources. Intrahepatic cholestasis of pregnancy is a disease that typically appears in the third trimester of pregnancy, sometimes already at the end of the second trimester of pregnancy. The main symptom of the disease is pruritus. In addition, the disease is characterized by increased levels of liver enzymes and bile acids. The symptoms of the disease disappear spontaneously after delivery. The disease is associated with high incidence of fetal distress, as well as with a high risk of premature labour. The most serious obstetric complication is antenatal sudden fetal death. Fetal complications are probably caused by elevated levels of bile acids. Therefore the aim of treatment should be to minimize negative effects of bile acids on the fetus, to prolong pregnancy and reduce maternal symptoms at the same time.

Laparoscopic sleeve gastrectomy differentially affects serum concentrations of FGF-19 and FGF-21 in morbidly obese subjects.

OBJECTIVE: Fibroblast growth factor (FGF)-19 and FGF-21 are novel metabolic regulators that improve insulin resistance and obesity in rodents. The aim of the study was to assess the effects of laparoscopic sleeve gastrectomy (LSG) on serum concentrations of FGF-19 and FGF-21 along with circulating bile acids and other relevant hormonal and biochemical parameters. DESIGN AND METHODS: Seventeen females with obesity undergoing LSG and 15 lean healthy females were included into the study. Anthropometric and biochemical parameters, serum concentrations of FGF-19 and -21, insulin, adiponectin, leptin, C-reactive protein, resistin, amylin (total), ghrelin (active), glucagon-like peptide 1 (GLP-1, active), glucose-dependent insulinotropic peptide (GIP, total), peptide YY (PYY, total), pancreatic polypeptide (PP), and bile acids, and mRNA expression of selected adipokines and inflammatory markers in bioptic samples of subcutaneous fat were assessed at baseline and 6, 12, and 24 months after LSG. RESULTS: LSG markedly decreased body weight, BMI, waist circumference, and insulin levels and improved systemic inflammation and lipid levels. FGF-19 concentrations increased and FGF-21 concentrations decreased after LSG along with increased adiponectin and decreased leptin, amylin, and ghrelin levels. GLP-1, GIP, PP, and circulating bile acids were not affected by LSG. PYY decreased significantly 24 months after surgery only. mRNA expression analysis in subcutaneous fat showed markedly reduced proinflammatory state. CONCLUSIONS: Our results indicate that increased FGF-19 and decreased ghrelin concentrations could have partially contributed to the improvement of systemic inflammation and some metabolic parameters after LSG, while changes of FGF-21 are rather secondary because of weight loss.

[Acute myocardial infarction in young patients--severe failures in the system of acute and secondary care]. / Akutní infarkt myokardu u mladých nemocných - závazné nedostatky v systému akutní a následné péce.

INTRODUCTION: The incidence of cardiovascular (CV) diseases and acute myocardial infarction (AMI) in Czech Republic is de-clining. In spite of this in a proportion of patients AMI occurs in young age. The aim of our project was to assess the character of risk factors, precipitating diseases and the quality of care in young AMI survivors. METHODS: We included 132 patients (97 men and 35 women) in whom AIM with ST elevations occurred before age of 45 years in men and age of 50 years in women. Several results were compared to a control group composed of 84 healthy volunteers of comparable age. We assessed the course of the disease, extent of coronary involvement, subsequent therapy and control of risk factors after 3 years from the index event. RESULTS: Smoking represented the main risk factor - 85% patents were active smokers at the time of AMI and 9% were former smokers, 64% patients had a positive family history of CV disease. We found a higher prevalence of dyslipidemia history in men. In spite of high rate of statin use, laboratory examination during follow-up revealed higher triglyceride values and low levels of HDL-cholesterol in both genders. All together 23% of patients had a history of provoking underlying disease or precipitating factors (inflammatory diseases, malignancies, combined thrombophilias, drug abuse). In total 95% of patients underwent coronary angiography during the acute phase of AMI, the median time from pain onset to intervention was 9 hours. Most patients had single vessel disease, 14% had even coronary angiogram without clinically significant stenosis. The subsequent care was satisfactory concerning the rate of drug prescriptions. However, target lipid values were not reached in 78% patients and blood pressure targets in 37%. CONCLUSIONS: In patients who suffered AMI in young age, risk factors are dominated by smoking and positive family history of CV diseases. One fifth of patients suffer from other underlying disease (inflammatory disease, malignancies, combined thrombophilia) or have another precipitating factor (febrile disease, drug abuse). The acute care seems unsatisfactory due to late arrival of most patients to catheterization laboratories (underestimation of the disease, incorrect initial diagnosis). Subsequent therapy is well composed but lacks in intensity.

Can adequate treatment influence the postembolization syndrome and cytokine release in patients undergoing iatrogenic renal artery embolization?

The complete renal artery embolization is an alternative to surgical nephrectomy in seriously ill patients. Iatrogenic embolization can be used in many different conditions. Refractory nephrotic syndrome represents a very rare indication for embolization. Complete renal artery embolization has usually been complicated by postembolization syndrome (PES) which is characterized by flank pain and fever. Possible immunologic contribution to the PES leads some authors to the administration of corticosteroids to the patients undergoing embolization. We report here a cohort of 13 patients undergoing complete embolization of total 21 kidneys due to refractory nephrotic syndrome non-responding to the various specific treatment regimes. We treated our patients undergoing renal artery embolization according to special protocol containing combination of antibiotic drugs and corticosteroids (CS) to diminish PES and evaluated its influence to the cytokine production. The incidence of PES was less frequent and milder in comparison with the historical group of patients. Significant decrease in plasma levels of tumor necrosis factor α during first post-embolization day (8.37 pre- vs. 5.74 pg/ml post-embolization, P=0.0002) could partially explain the reduction of PES symptoms. The procedure was not complicated by severe complications and represents an elegant alternative to surgical procedure. The accurate timing of the embolization remains a controversial point in this intervention.

Sleep disorders in Wilson's disease.

BACKGROUND: Wilson's disease (WD) is an autosomal recessive inherited disease with copper accumulation; neurodegeneration is associated with dopaminergic deficit. The aim of the study is to verify sleep co-morbidity by questionnaire and objective sleep examinations (polysomnography, multiple sleep latency test). METHODS: fifty-five patients with WD (22 hepatic, 28 neurological, five asymptomatic form) and 55 age- and sex-matched control subjects completed a questionnaire concerning their sleep habits, sleep co-morbidity, Epworth sleepiness scale (ESS), and answered screening questions for rapid eye movement (REM) behaviour disorder (RBD-SQ). Twenty-four patients with WD and control subjects underwent polysomnographic examination. RESULTS: unlike the controls, patients with WD were more prone to daytime napping accompanied by tiredness and excessive daytime sleepiness, cataplexy-like episodes and poor nocturnal sleep. Their mean ESS as well as RBD-SQ was higher than that of the controls. Total sleep time was lower, accompanied by decreased sleep efficiency and increased wakefulness. Patients with WD had lower latency of stage 1 and stage 2 of non-rapid eye movement (NREM) sleep and less amount of NREM sleep stage 2. One-third of the patients with WD were found to have short or borderline multiple sleep latency test (MSLT) values independent of nocturnal pathology (sleep apnoea, periodic leg movements and/or restless leg syndrome). CONCLUSIONS: patients with WD often suffer from sleep disturbances (regardless of the clinical form). The spectrum of sleep/wake symptoms raises the suspicion that altered REM sleep function may also be involved.

Association of systemic lupus erythematosus with low serum bilirubin levels.

OBJECTIVE: Systemic lupus erythematosus (SLE) is accompanied by severe oxidative stress. Bilirubin has been reported as a strong negative predictor of oxidative stress-mediated diseases, such as atherosclerosis. The objective of our study was to evaluate the association between serum bilirubin levels and SLE manifestation. METHODS: The study was performed with 259 SLE patients, diagnosed according to American Rheumatism Association (ARA) criteria. A subset of these patients, having normal hepatic function (n = 218, mean age 39.5 years), was studied in greater detail to eliminate the possible confounding effects of any underlying or drug-induced liver disease on the serum bilirubin levels. Age-matched healthy subjects (n = 180) served as the control group. A standard biochemical and immunological work-up was performed on all subjects. RESULTS: Compared to the controls, substantially lower levels of serum bilirubin were detected in SLE patients (p < 10⁻5); these were inversely correlated with disease activity and extent (p < 0.05). Furthermore, each 1 µmol/L decrease in serum bilirubin was associated with a 37% increase in the odds for a positive SLE status [odds ratio (OR) 1.37, 95% confidence interval (CI) 1.28-1.47, p < 10⁻5]. Simultaneously, the odds of unconjugated hyperbilirubinaemia (a phenotypic sign of Gilbert's syndrome) were more than four times lower in SLE patients (OR 0.235, 95% CI 0.072-0.764, p = 0.016). CONCLUSION: Low serum bilirubin represented a strong predictor of the manifestation of SLE symptoms. The most likely explanation for this finding is the increased consumption of bilirubin due to the severe oxidative stress accompanying SLE. Subjects with higher serum bilirubin levels, such as those with Gilbert's syndrome, might be protected from the development of SLE.