Relationship among hepatic inflammatory changes, circulating levels of cytokines, and response to IFN-alpha in chronic hepatitis C

Hepatogenous diabetes: Is it time to separate it from type 2 diabetes?

By definition, hepatogenous diabetes is directly caused by loss of liver function, implying that it develops after cirrhosis onset. Therefore, it should be distinguished from type 2 diabetes developing before cirrhosis onset, in which specific causes of liver disease play a major role, in addition to traditional risk factors. Currently, although hepatogenous diabetes shows distinct pathophysiological and clinical features, it is not considered as an autonomous entity. Recent evidence suggests that the failing liver exerts an independent "toxic" effect on pancreatic islets resulting in β-cell dysfunction. Moreover, patients with hepatogenous diabetes usually present with normal fasting glucose and haemoglobin A_1c levels and abnormal response to an oral glucose tolerance test, which is therefore required for diagnosis. This article discusses the need to separate hepatogenous diabetes from type 2 diabetes occurring in subjects with chronic liver disease and to identify individuals suffering from this condition for prognostic and therapeutic purposes.

Interferon-gamma is associated with hepatic dysfunction in fibrosis, cirrhosis, and hepatocellular carcinoma

The relation between interferon-gamma (IFN-γ) levels and the severity of liver diseases through fibrosis, cirrhosis, and hepatocellular carcinoma (HCC) has not been fully clarified. Thus, we aimed to characterize IFN-γ levels in liver-diseased patients. IFN-γ levels were determined by Western-blot and ELISA in sera from 30 healthy individuals, 53 patients with non-significant fibrosis (F0-F1), 47 with moderate/severe fibrosis (F2-F3), 44 cirrhotic patients (F4), and 50 with HCC. Enhanced levels of IFN-γ were associated with the progression of liver disease. The differences were statistically significant (P < 0.0001) when patients with F2-F3, F4, or HCC were compared with F0-F1 or healthy controls. The increase in IFN-γ was associated with HCC (OR = 0.98, 95% CI 0.97-0.99, P = 0.002). There was no statistically significant association between IFN-γ levels and HCV-RNA (IU/ml) (r = 0.1, P = 0.43) or HCV-NS4 (µg/mL) (r = 0.1, P = 0.17). There was significant (P < 0.0001) association between IFN-γ levels and the fibrosis stages and activity, albumin, platelet count, total bilirubin, and international normalized ratio (INR). In conclusion, elevated concentrations of IFN-γ represent a characteristic feature of liver disease severity regardless of underlying disease. Significant correlations with indices of hepatic dysfunction suggest that enhanced IFN-γ levels represent a consequence of liver dysfunction rather than of inflammatory disease.

Liver fibrosis, host genetic and hepatitis C virus related parameters as predictive factors of response to therapy against hepatitis C virus in HIV/HCV coinfected patients

OBJECTIVE

To establish the role of liver fibrosis as a predictive tool of response to pegylated interferon alpha (Peg-IFN) and ribavirin (RBV) treatment in human immunodeficiency (HIV)/hepatitis C virus (HCV) coinfected patients, in addition to recognized predictive factors (HCV load, HCV genotype, IL-28B polymorphism).

PATIENTS AND METHODS

A sample of 267 HIV/HCV coinfected patients was treated with Peg-IFN and RBV. Predictive factors of rapid (RVR) and sustained (SVR) virological response were analyzed. Independent variables were age, sex, IL28B, -238 TNF-α and -592 IL-10 polymorphisms, HCV genotype, HCV-RNA levels, significant fibrosis or cirrhosis and CD4+ T cell count.

RESULTS

Patients infected by HCV genotype 1 (n = 187) showed RVR and SVR in 12% and 39% of cases, respectively. The parameters associated with RVR were IL28B genotype CC and plasma HCV-RNA levels <600,000 IU/ml. Advanced liver fibrosis was negatively associated with SVR in patients without RVR. A SVR was obtained in 42% of subjects with HCV genotype 4, and the independent factors associated with SVR were IL28B genotype CC and an HCV-RNA <600,000 IU/ml. A SVR was obtained in 66% of patients with HCV genotypes 2/3; in this case, the independent parameter associated with SVR was the absence of significant liver fibrosis. TNF-α and IL-10 polymorphisms were not associated with SVR, although a significantly higher percentage of -238 TNF-α genotype GG was detected in patients with significant liver fibrosis.

CONCLUSIONS

In HIV/HCV coinfected patients with HCV genotypes 1 or 4, RVR, mainly influenced by genotype IL28B and HCV-RNA levels, reliably predicted SVR after 4 weeks of therapy with Peg-IFN plus RBV. In patients infected by HCV genotype 3, an elevated relapse rate compromised the influence of RVR on SVR. Relapses were related to the presence of advanced liver fibrosis. Liver cirrhosis was associated with a -238 TNF-α polymorphism in these patients.

Liver disease and diabetes: association, pathophysiology, and management

Diabetes is associated with a spectrum of liver diseases including nonalcoholic liver disease, steatohepatitis, and liver cirrhosis with their increased complications and mortality. Hepatitis C virus (HCV) and its associated liver cirrhosis has been associated with diabetes through insulin resistance. Cryptogenic diabetes occurs as a consequence of liver cirrhosis with the pathophysiology being complex, but mostly attributed to the increased insulin resistance in muscle, liver, and adipose tissue. As for the management of diabetes in patients with liver disease, lifestyle modification plays an important role. Oral diabetic medications are contraindicated in patients with advanced liver diseases with associated cirrhosis, ascites, or encephalopathy. As for stable liver disease, metformin and thiazolenediones have shown mixed results, with some showing them to be effective in improving liver transaminases in addition to histological improvement in steatosis and inflammation. α-glucosidase inhibitors may be helpful in decreasing hepatic encephalopathy. Upregulation of Dipeptidyl peptidase-4 (DPP-4) has been suggested as a possible pathogenetic mechanism for HCV-related insulin resistance, and treatment with DPP-4 inhibitors could improve insulin sensitivity in diabetic patients with liver disease. Patients with impaired liver function with associated insulin resistance may need increased insulin requirements. On the other hand patients with altered liver metabolism might need decreased insulin requirements.

Influence of Genetic Polymorphisms of Tumor Necrosis Factor Alpha and Interleukin 10 Genes on the Risk of Liver Cirrhosis in HIV-HCV Coinfected Patients

OBJECTIVE

Analysis of the contribution of genetic (single nucleotide polymorphisms (SNP) at position -238 and -308 of the tumor necrosis factor alpha (TNF-α) and -592 of the interleukin-10 (IL-10) promotor genes) and of classical factors (age, alcohol, immunodepression, antirretroviral therapy) on the risk of liver cirrhosis in human immunodeficiency (HIV)-hepatitis C (HCV) virus coinfected patients.

PATIENTS AND METHODS

Ninety one HIV-HCV coinfected patients (50 of them with chronic hepatitis and 41 with liver cirrhosis) and 55 healthy controls were studied. Demographic, risk factors for the HIV-HCV infection, HIV-related (CD4+ T cell count, antiretroviral therapy, HIV viral load) and HCV-related (serum ALT concentration, HCV viral load, HCV genotype) characteristics and polymorphisms at position -238 and -308 of the tumor necrosis factor alfa (TNF- α) and -592 of the interleukin-10 (IL-10) promotor genes were studied.

RESULTS

Evolution time of the infection was 21 years in both patients' groups (chronic hepatitis and liver cirrhosis). The group of patients with liver cirrhosis shows a lower CD4+ T cell count at the inclusion in the study (but not at diagnosis of HIV infection), a higher percentage of individuals with previous alcohol abuse, and a higher proportion of patients with the genotype GG at position -238 of the TNF-α promotor gene; polymorphism at -592 of the IL-10 promotor gene approaches to statistical significance. Serum concentrations of profibrogenic transforming growth factor beta1 were significantly higher in healthy controls with genotype GG at -238 TNF-α promotor gene. The linear regression analysis demonstrates that the genotype GG at -238 TNF-α promotor gene was the independent factor associated to liver cirrhosis.

CONCLUSION

It is stressed the importance of immunogenetic factors (TNF-α polymorphism at -238 position), above other factors previously accepted (age, gender, alcohol, immunodepression), on the evolution to liver cirrhosis among HIV-infected patients with established chronic HCV infections.

Hepatoprotective effect of silyamarin in individuals chronically exposed to hydrogen sulfide; modulating influence of TNF-α cytokine genetic polymorphism

BACKGROUND AND THE PURPOSE OF THE STUDY

Silymarin, a standardized extract of the milk thistle (Silybum marianum), is believed to exert some of its hepatoprotective effects though inhibition of free radicals and inflammation. In this study the effect of some pro- and anti-inflammatory cytokines and also antioxidant genes polymorphisms on the hepatoprotective effects of silymarin in the occupationally exposed individuals to hydrogen sulfide (H2S) in the sour natural gas refinery was investigated.

METHODS

We genotyped seven polymorphisms in six genes reported by others as modifiers of oxidative stress (NQO1, mEPXH1, GSTT1 and GSTM1) and inflammation (TNF-α and TGF-β1) for an association in effect of decreasing in liver function tests (LFTs). The LFTs of 77 sour gas refinery workers were measured before and after administration of silymarin (140 mg, three times per day for 1 month).

RESULTS

A significant reduction of blood AST, ALT and ALP was observed after 30 days of consumption (p < 0.001). The decreasing effect of silymarin on ALT in the subjects with high producer genotype (A allele carriers) was less than low producers. There were no significant associations between TGF-β1 and the studied genes of oxidative stress pathway and the effectiveness of silymarin.

CONCLUSION

This is the first report about the effectiveness of silymarin in the subjects exposed chronically to H2S. Meanwhile, the modulatory effect of TNF-α on the effectiveness of silymarin might be used for individualize therapy.

Association of interleukin-18 polymorphisms and plasma level with the outcome of chronic HCV infection

Hepatitis C virus (HCV) infection is the main cause of chronic liver disease throughout the world, and may progress to cirrhosis and hepatocellular carcinoma (HCC). Immunological factors, especially cytokines and some host genetic variations, rather than direct HCV action, seem to play an important role in the pathogenesis of HCV infection. Elevated levels of interleukin-18 (IL-18) were described previously for chronically (HCV)-infected patients. This study is aimed at investigating IL-18 promoter polymorphisms (-607C/A and -137G/C) in HCV-infected patients with different disease severities (chronic hepatitis C, liver cirrhosis and HCC) and establishing an association between these polymorphisms and IL-18 plasma concentration with the outcome of chronic HCV infection. The carriage of at least one C allele at position -607 (CC + CA) was associated with a higher risk of cirrhosis and HCC (P = 0.032). Compared with controls, HCV-infected patients had significantly higher levels of IL-18 (P = 0.0001) that correlate with disease severity (P = 0.01, P = 0.001, P = 0.0006, respectively). In conclusion, we supposed a possible implication of IL-18 promoter polymorphisms in the pathogenesis of chronic HCV infection.

Immunomodulators, sFas and Fas-L as potential noninvasive predictors of IFN treatment in patients with HCV genotype-4

Recent studies have indicated that cytokines can be used as markers for disease progression in hepatitis C virus (HCV)-infected patients, therefore this study was conducted to determine the influence of pegylated IFN vs standard IFN on interleukin-2 receptor (IL-2R), IL-6R, IL-8, TNFR-I, TNFR-II, sFas, and sFas-L in Egyptian patients with chronic hepatitis C genotype 4, as no previous studies have been performed on this genotype. We also aim at establishing a possible relationship between these cytokines and the response to INF to determine whether they can be used as noninvasive markers for the response to INF therapy and as monitors for the outcome of treatment. Thirty-eight patients with chronic HCV hepatitis were investigated for the serum levels of the previously mentioned cytokines in a randomized opened controlled trial (22 patients treated with pegylated IFN and 16 patients treated with standard IFN). Cytokine levels were measured by ELISA at 0, 1 and 12 months of IFN therapy. There was marked increase in the serum levels of IL-2R and IL-6R in nonresponders to pegylated interferon, IL-8, TNFR-I and II were significantly higher in nonresponders to standard interferon but were also high in responders of pegylated interferon. sFas and sFas-L showed high levels among responders to pegylated interferon but the standard interferon was again less effective in this regard. Serum levels of TNFR-II, sFas and sFas-L have the potential to be used as serological markers for response to pegylated IFN therapy, and IL-8 is a predictor for nonresponse. Moreover, TNFR-I and II have the potential to be used as markers of response to standard IFN treatment. The persistent correlation between sFas and TNFR-II may elaborate the possible role of pegylated IFN in the induction of apoptosis as a possible new mechanism of viral clearance during treatment with pegylated interferon treatment.

Effect of cytokine gene polymorphism on histological activity index, viral load and response to treatment in patients with chronic hepatitis C genotype 3

AIM: To investigate the association between cytokine gene polymorphism and disease status in chronic hepatitis C genotype 3 by liver biopsy, ALT, HCV RNA levels and response to treatment.

METHODS: Patients with chronic hepatitis C genotype 3 were analyzed for single nucleotide polymorphisms of interleukin (IL)-10, IL-1 beta, interferon-gamma (IFN-γ), tumor necrosis factor-alpha (TNF-α) and transforming growth factor-beta (TGF-β) by polymerase chain reaction using sequence-specific oligonucleotide primers. Liver biopsies were assessed by modified histological activity index (HAI) scoring system using a scale of 0–18 for grading the necro-inflammatory activity and 0–6 for staging the fibrosis. HCV RNA levels were determined by bDNA assay. The patients were treated with interferon alpha and ribavirin for 6 mo. Sustained virological response was assessed 6 mo after the completion of the treatment.

RESULTS: Out of the 40 patients analyzed, 26 were males. Mean age was 40.5±12.5 years (range 18–65 years). The frequencies of different dimorphic polymorphisms based on single nucleotide substitution were as follows: IL-10-1082 G/A 85%, A/A 12.5%, G/G 2.5%; IL-10-819 A/C 87.5%, C/C 10%, A/A 2.5%; IL-10-592 C/A 72.5%, C/C 27.5%; IL-1 C 90%, U 10%; IFN-874 T/A 50%, T/T 27.5%, A/A 22.5%; TNF-308 A/G 95%, G/G 5%; TGF-10 T/C 52.5%, C/C 35%, T/T 12.5%. The mean grades of necro-inflammatory activity of different genotypes of IL-10 at promoter site -1082 were A/A = 3.6, A/G = 5.0, and G/G = 10.0 and the difference was significant (P = 0.029). The difference in the stage of disease at a scale of 0–6 was A/A 0.8, A/G 2.3, and G/G 4.0 (P = 0.079). The difference in the HAI seemed to be related to the presence of allele -1082G. For IL-10 -819 genotypes, mean scores of fibrosis were A/A = 6.0, A/C = 2.2, and C/C = 1.0 (P = 0.020) though the inflammatory activity was not much different. No significant differences in HAI were noted among polymorphisms of other cytokines. Moreover, ALT and HCV RNA levels were not significantly different among different cytokine polymorphisms. There was a significant correlation of HAI and HCV RNA levels with the duration of disease. TGFβ -10 genotype CC patients had a better end of treatment response than those with other genotypes (P = 0.020). Sustained virological response to the treatment was not influenced by the cytokine polymorphism. No effect of other factors like viral load, degree of fibrosis, gender, steatosis, was observed on sustained virological response in this population infected with genotype 3.

CONCLUSION: There is no significant correlation between cytokine polymorphisms and HAI except for the polymorphisms of anti-inflammatory cytokine IL-10, which may influence hepatic inflammatory activity and fibrosis in patients with chronic hepatitis C genotype 3. Sustained virological response in this genotype does not seem to be influenced by cytokine gene polymorphisms.

High concentrations of the melatonin metabolite, N1-acetyl-N2-formyl-5-methoxykynuramine, in cerebrospinal fluid of patients with meningitis: a possible immunomodulatory mechanism

We evaluated the presence of the melatonin metabolite N1-acetyl-N2-formyl-5-methoxykynuramine (AFMK), in cerebrospinal fluid (CSF) of patients with viral meningitis (n = 20) and control samples (n = 8) and correlate AFMK levels with inflammatory markers such as cellularity, protein, tumor necrosis factor (TNF)-alpha, interleukin (IL)-8 and IL-1beta levels. A portion of the CSF was extracted with dichloromethane (1:5) and analyzed by high-performance liquid chromatography (HPLC) under standardized conditions for AFMK. AFMK was detected in 16 of 20 CSF samples of patients with viral meningitis; the concentration of AFMK was found to be above the quantification limit (50 nmol/L) in six of these samples. AFMK was not detected in any of the eight control samples. The samples were classified into groups according to AFMK levels: undetectable (<10 nmol/L, group I), detectable but below the quantification limit (< 50 nmol/L, group II), and quantified (>50 nmol/L, group III). Group II presented the highest levels of proteins and IL-8, whereas group III showed the lowest levels of the inflammatory parameters. This study supports our hypothesis that inflammation favors the formation of AFMK and that this compound has immunomodulatory activity in vivo.

Neutrophils as a specific target for melatonin and kynuramines: effects on cytokine release

A growing body of evidence suggests that the pineal hormone, melatonin, has immunomodulatory properties, although very little is known about its effect on leukocytes. Therefore, we aimed to investigate the effect of melatonin and its oxidation product N1-acetyl-N2-formyl-5-methoxykynuramine (AFMK) on cytokine production by neutrophils and peripheral blood mononuclear cells (PBMCs). AFMK (0.001-1 mM) inhibits the lipopolysaccharide (LPS)-mediated production of tumor necrosis factor-alpha (TNF-alpha) and interleukin-8 (IL-8) more efficiently in neutrophils than PBMCs. Moreover, the inhibitory activity of AFMK is stronger than that of melatonin. Interestingly, monocytes efficiently oxidize melatonin to AFMK. We conclude that neutrophils are one of the main targets for melatonin and that at least part of the effects described for melatonin on immune cells may be due to its oxidation product, AFMK. We also consider that the oxidation of melatonin may be an important event in the cross-talking between neutrophils and monocytes.

Tumor necrosis factor-alpha-induced insulin resistance may mediate the hepatitis C virus-diabetes association

OBJECTIVES

Among patients infected with hepatitis C virus (HCV), 13-33% develop type 2 diabetes mellitus (DM). The mechanism for this remains unclear. Because tumor necrosis factor-alpha (TNF-alpha) has been identified as a mediator of insulin resistance and is induced by HCV, we examined TNF-alpha and proinflammatory cytokines in noncirrhotic patients with chronic hepatitis C, both with and without diabetes.

METHODS

HCV-infected patients with type 2 DM (n = 23) were compared with age- and sex-matched patients with chronic hepatitis C and without DM (n = 28), patients with DM and without HCV (n = 31), and healthy controls (n = 21). Serum levels of TNF-alpha, interleukin-1beta (IL-1beta), interleukin-6 (IL-6), and soluble TNF receptors (sTNFR) 1 (p55) and 2 (p75) were determined by ELISA.

RESULTS

Detectable serum TNF was found in 74% of the HCV/DM patients, versus 64% of the nondiabetic HCV group and < or =10% in the other groups. Mean sTNFR1 in the HCV/DM group was 1931 pg/ml (95% CI = 1449-2413), compared with 1289 pg/ml (95% CI = 1101-1476) in nondiabetic HCV patients, with similar values in the other two groups (p = 0.001). The mean sTNFR2 level in the HCV/DM patients was 3326 pg/ml (95% CI = 2924-3727) compared with 2367 pg/ml (95% CI = 1951-2784) in the nondiabetic HCV patients, and similar results in the other groups (p < 0.0001). Serum IL-1beta, IL-6, and C-reactive protein were not significantly different between HCV patients with or without DM.

CONCLUSIONS

Excessive TNF-alpha response characterizes HCV-infected patients who develop DM. STNFR may be a marker for the development of DM in chronic hepatitis C.

Generating hypotheses by discovering implicit associations in the literature: a case report of a search for new potential therapeutic uses for thalidomide

The availability of scientific bibliographies through online databases provides a rich source of information for scientists to support their research. However, the risk of this pervasive availability is that an individual researcher may fail to find relevant information that is outside the direct scope of interest. Following Swanson's ABC model of disjoint but complementary structures in the biomedical literature, we have developed a discovery support tool to systematically analyze the scientific literature in order to generate novel and plausible hypotheses. In this case report, we employ the system to find potentially new target diseases for the drug thalidomide. We find solid bibliographic evidence suggesting that thalidomide might be useful for treating acute pancreatitis, chronic hepatitis C, Helicobacter pylori-induced gastritis, and myasthenia gravis. However, experimental and clinical evaluation is needed to validate these hypotheses and to assess the trade-off between therapeutic benefits and toxicities.

Long-term efficacy of treatment of chronic hepatitis C with alpha interferon or alpha interferon and ribavirin

The major objective of treatment of chronic hepatitis C virus (HCV) infection is to prevent progression to cirrhosis, and thereby prevent complications of end-stage liver disease. The established treatment of chronic HCV is with alpha interferon. Recent results with ribavirin and alpha interferon together suggest that combination antiviral therapy will become the benchmark treatment. For both naive and relapsed patients, however, it has become important to assess the long-term outcome of treatment, in order to gauge whether treatment has indeed modified the natural history of chronic hepatitis C virus infection. It seems likely that most sustained responders (85-90%) treated with combination ribavirin and alpha interferon will continue to have a long-term biochemical and virological response, as has been demonstrated with alpha interferon alone, but further long-term follow-up of patients treated with combination therapy is required.

Predictors of sustained response to alpha interferon therapy in chronic hepatitis C

OBJECTIVES

To utilize cytokine levels to predict sustained response (SR) to alpha interferon (IFN alpha) therapy in chronic hepatitis C patients, and to determine the relationship between serum tumor necrosis factor alpha (TNF alpha), interleukin (IL) IL 6, IL 8, IL 12, transforming growth factor beta (TGF beta 1) and the degree of liver damage as reflected by traditional markers.

DESIGN AND METHODS

Serum cytokine levels were assessed using ELISA in 18 patients included in a controlled clinical trial of IFN alpha.

RESULTS

Of the 18 patients, 27% were sustained responders (SR), 27% were response and relapse responders (RR), and 46% were non-responders (NR). Multivariate analysis showed that a low serum TNF alpha level and high serum IL 8 levels were independent factors associated with SR to IFN alpha therapy. Serum TNF alpha level highly correlated with viral load and genotype predictive values (p < 0.001). Therapy lowered the IL 6 and IL 12 profile. TGF beta 1 levels in serum are positively correlated with fibrinogenesis.

CONCLUSIONS

IFN alpha therapy modulates immune response to hepatitis C virus, contributing to sustained response.

Kinetics of serum soluble tumour necrosis factor receptor (TNF-R) type-I and type-II after a single interferon-alpha (IFN-alpha) injection in chronic hepatitis C

Circulating soluble TNF receptors, which act as TNF inhibitors, increase following the administration of IFN-alpha. Whether this is due to a direct IFN action or to indirect mechanisms involving the release of other cytokines is unclear. The kinetics of serum IFN, TNF, IL-6, IL-10, soluble TNF receptor type-I (sTNF-RI) and sTNF-RII were evaluated by enzyme immunoassays in 11 patients with chronic hepatitis C, following the first dose of recombinant human IFN-alpha2b (3 MU given subcutaneously). sTNF-RI concentrations paralleled IFN concentrations, rising from a mean +/- s.e.m. value of 3.5 +/- 0.3 ng/ml at baseline to a peak value of 5.5 +/- 0.5 ng/ml after 9 h, followed by a return to 4.1 +/- 0.4 ng/ml after 24 h (P = 0.0001). sTNF-RII concentrations, which were 7.6 +/- 0.5 ng/ml at baseline, fell initially to 6.9 +/- 0.5 ng/ml, to reach a peak at 24 h of 9.0 +/- 0.7 ng/ml (P < 0.0001). In contrast, the concentrations of TNF, IL-6 and IL-10 fluctuated with no significant changes at any time point. The area under the curve (AUC) of incremental IFN values had a strong positive correlation with the AUC of incremental sTNF-RI values (r = 0.75, P < 0.01). In patients with hepatitis C, IFN concentrations reached after a single dose of IFN were paralleled by correlationally increased concentrations of sTNF-RI, which are a much better marker of administered IFN than sTNF-RII, IL-6 or IL-10.

Serum erythropoietin and interleukin-6 levels in hemodialysis patients with hepatitis virus infection

The influence of hepatitis B (HBV) and hepatitis C virus (HCV) infection on blood hemoglobin (Hb) and serum erythropoietin (Epo) and interleukin-6 (IL-6) concentrations was studied in 48 anemic patients on regular hemodialysis. They were grouped as follows: (I) 19 patients whose Hb values improved after infection (Hb > 85 g/L), (II) 10 patients with persisting anemia after infection (Hb < 75 g/L), and, without hepatitis virus markers (III) 8 patients with Hb > 85 g/L and (IV) 11 patients with Hb < 75 g/L. Serum immunoreactive Epo levels were significantly higher in group I (34.4+/-47.1 U/L) than in the other groups (II, 10.8+/-6.0; III, 7.9+/-3.2; IV, 8.4+/-4.3). Serum IL-6 was higher in group I than group III (7.7+/-7.8 pg/ml vs. 3.6+/-2.4; p = 0.05) but similar to the other groups. Hb levels in group I were maximal at the time of serum alanine aminotransferase normalization. Red cell production increases as a result of elevated circulating Epo during hepatic regeneration after HBV or HCV infection.