A Revised Classification of Primary Iron Overload Syndromes

BACKGROUND AND AIMS

The clinical introduction of hepcidin25 (Hep25) has led to a more detailed understanding of its relationship with ferroportin (FP) and divalent metal transporter1 in primary iron overload syndromes (PIOSs). In 2012, we proposed a classification of PIOSs based on the Hep25/FP system, which consists of prehepatic aceruloplasminemia, hepatic hemochromatosis (HC), and posthepatic FP disease (FP-D). However, in consideration of accumulated evidence on PIOSs, we aimed to renew the classification.

METHODS

We reviewed the 2012 classification and retrospectively renewed it according to new information on PIOSs.

RESULTS

Iron-loading anemia was included in PIOSs as a prehepatic form because of the newly discovered erythroferrone-induced suppression of Hep25, and the state of traditional FP-D was remodeled as the BIOIRON proposal. The key molecules responsible for prehepatic PIOSs are low transferrin saturation in aceruloplasminemia and increased erythroferrone production by erythroblasts in iron-loading anemia. Hepatic PIOSs comprise four genotypes of HC, in each of which the synthesis of Hep25 is inappropriately reduced in the liver. Hepatic Hep25 synthesis is adequate in posthepatic PIOSs; however, two mutant FP molecules may resist Hep25 differently, resulting in SLC40A1-HC and FP-D, respectively. PIOS phenotypes are diagnosed using laboratory tests, including circulating Hep25, followed by suitable treatments. Direct sequencing of the candidate genes may be outsourced to gene centers when needed. Laboratory kits for the prevalent mutations, such as C282Y, may be the first choice for a genetic analysis of HC in Caucasians.

CONCLUSIONS

The revised classification may be useful worldwide.

Use of a specific monoclonal antibody to detect Mallory bodies in liver disease

Mallory bodies (MBs), which are common in alcoholic hepatitis, primary biliary cirrhosis and liver disease associated with Type II diabetes mellitus, are often difficult to find on liver biopsy specimens or to predict from clinical or biochemical studies. Immunofluorescence studies with anti-NMB-1, a Mallory body-specific monoclonal antibody, indicate that this is a sensitive method for recognizing Mallory bodies in cryostat sections of liver from griseofulvin-treated mice or patients with liver disease. Validity of the leukocyte migration test, which facilitates detection and monitoring of patients who harbor Mallory bodies, is confirmed by pretreatment of Mallory bodies with anti-NMB-1. Prevention of Mallory body-induced migration inhibition by addition of anti-NMB-1 indicates that this effect is not due to inactivation of leukocytes by a Mallory body contaminant. Anti-NMB-1, developed using standard hybridoma techniques, does not react with normal hepatocytes or other cells. Investigations with SDS polyacrylamide gel electrophoresis and western blotting reveal that it exhibits binding with 62, 55, 42 kd peptides, and four other bands in the range from 40 to 30 kd from the Mallory bodies. The NMB-1 epitope which facilitates morphologic and clinical detection of Mallory bodies is distinct from cytokeratin and appears to be responsible for its immunogenicity.

Occurrence of immunohistochemically detected small Mallory bodies in liver disease

To determine the diagnostic significance of immunohistochemically detected small Mallory bodies (MBs) which are invisible by conventional stainings, we investigated the occurrence of MBs in liver tissue with alcoholic and nonalcoholic liver disease by immunoperoxidase staining with monoclonal anti-MB antibody, anti-NMB-3. In conventional stainings, MBs were detected in only six of 26 (23%) patients with alcoholic liver disease, and nine of 63 (14%) patients with nonalcoholic liver disease. On the other hand, MBs were detected in 20 of 26 (77%) patients with alcoholic liver disease, and 25 of 63 (40%) patients with nonalcoholic liver disease by immunoperoxidase staining. Immunohistochemically detected MBs were shown to possess the ultrastructural characteristics of MBs by immunoelectronmicroscopy in the four specimens. Our result indicates that the small MBs are not rare in nonalcoholic liver disease, and the presence of immunohistochemically detected small MBs is not a good marker of an alcoholic etiology.

Increased peripheral blood Ia positive T cells and their effect on autologous mixed lymphocyte reaction in chronic active liver disease

We measured Ia antigen bearing peripheral blood T cells, as an index of immunological stimulation, of patients with chronic active liver diseases (CALD) by the rosette assay method. We also examined the role of Ia antigen which represents the products of the genes of the major histocompatibility complex on the autologous mixed lymphocyte reaction (AMLR) since this reaction may reflect self regulation of immune responses. The percentages of Ia positive T cells of 29 patients with CALD (17.1 +/- 4.3%, P less than 0.001) and of 12 patients with other liver diseases (12.9 +/- 2.4%, P less than 0.05) were increased when compared with that of normal individuals (10.7 +/- 2.0%). However, levels of Ia positive T cells activated by phytohaemagglutinin-P in patients with CALD and other liver diseases did not differ from normal subjects. Ia positive cells in OKT8 positive cells were markedly elevated (P less than 0.001), whereas those in OKT4 positive cells were decreased (P less than 0.01) in CALD. The impaired values for the AMLR correlated inversely (P less than 0.01) with the increased percentages of Ia positive T cells in patients with CALD. Further analysis showed that there was no suppression of the proliferation of Ia and OKT4 positive cells by Ia and OKT8 positive cells although the culture of increasing numbers of Ia and OKT8 positive cells and decreasing numbers of Ia and OKT4 positive cells gave a lesser AMLR value. These data suggest that the increase in Ia positive T cells and the alteration of Ia positive cells in the T cell subsets reflect an activation of immune system and provide further evidence in favour of an abnormality of the immunoregulatory system in CALD.

Antibody to liver-specific lipoprotein in acute and chronic liver diseases. Its quantitative assay with monoclonal antibody, but without the use of liver-specific lipoprotein

A double-antibody radioimmunoassay was developed to detect antibody to human liver-specific membrane lipoprotein (anti-LSP antibody) in patients' serum. Anti-human LSP monoclonal antibody was labeled with 125I and anti-anti-LSP antiserum raised in rabbits was used as the first antibody in the assay. Anti-LSP antibody level was quantitatively measured and the assay was shown to be specific. Anti-LSP antibody was found in 5/8 patients with type B acute viral hepatitis (AVH), 3/7 patients with type A AVH, 1/6 patients with non-A, non-B AVH, 10/17 patients with chronic active hepatitis (CAH), 6/16 patients with chronic persistent hepatitis, 13/16 patients with active cirrhosis of the liver and 7/19 patients with primary nonhepatic autoimmune diseases such as glomerulonephritis, systemic lupus erythematosus and rheumatoid arthritis. The mean levels of anti-LSP were increased in patients with cirrhosis of the liver (p less than 0.01), CAH (p less than 0.05) and AVH (p less than 0.05) when compared with that of normal individuals. However, the frequencies of anti-LSP did not depend on HBsAg status. The data showed that anti-LSP antibody can be detected without the use of LSP preparation although it is also found in patients with primary nonhepatic autoimmune diseases.

Serum interleukin 6 levels in patients with chronic hepatitis B

Studies were undertaken to evaluate the role of interleukin 6 (IL-6) in the pathogenesis of chronic hepatitis B. Using recently developed sensitive and specific enzyme-linked immunosorbent assay, we determined serum levels of IL-6 in patients with chronic active hepatitis B (B-CAH), chronic persistent hepatitis B (B-CPH), and primary biliary cirrhosis (PBC). Serum IL-6 activity tended to increase in patients with B-CAH (38.4 +/- 68.0 pg/ml) (+/- SD), compared with controls (9.7 +/- 6.8 pg/ml), although the difference was not significant because of the wide scatter in values. IL-6 levels in B-CPH and PBC were similar to those of controls. There was a significant correlation between the levels of IL-6 and aminotransferase in B-CAH. In addition, IL-6 activity was significantly enhanced during acute exacerbation of the illness, accompanied by clearance of HBeAg. Patients who received IFN-alpha and IL-2 therapy showed depressed IL-6 activity during treatment, and a rebound beyond pretreatment values after cessation of therapy. These findings suggest that IL-6 plays a role in the development of chronic hepatitis B, and it may contribute, at least in part, to the elimination of HB virus.

In vitro production of antimitochondrial antibody by peripheral blood mononuclear cells in patients with primary biliary cirrhosis

Peripheral blood mononuclear cells from patients with primary biliary cirrhosis (PBC) were studied for their ability to produce antibodies to mitochondrial antigens (antimitochondrial antibody, AMA and anti-pyruvate dehydrogenase complex, anti-PDC), using dot-immunobinding and ELISA assay. 2 x 10(6) B cells alone and the mixture of 1.4 x 10(6) T plus 0.6 x 10(6) B cells from patients with serum AMA+ PBC spontaneously produced similar amounts of AMA and anti-PDC. Coculture experiments of T and B cells showed that anti-PDC production was significantly greater in pokeweed mitogen (PWM)-stimulated cultures than in unstimulated ones. The reactivities of antibodies to mitochondrial antigens were inhibited by M2 mitochondrial antigen-enriched fraction. Ursodeoxycholic acid added to cultures resulted in a significant inhibition for production of immunoglobulins and anti-PDC (IgG and IgM). Spontaneous production of AMA or anti-PDC was not detected in patients with AMA- PBC, chronic viral hepatitis and healthy controls, nor could it be induced by PWM in either group. EBV-transformed B cell line established from a AMA+ PBC patient produced high levels of AMA and IgM class anti-PDC. These findings indicate that antibody to a specific mitochondrial antigen in patients with PBC may be produced in T cell-dependent and-independent manner.

Interleukin 1 alpha production by peripheral blood monocytes from patients with chronic liver disease and effect of sera on interleukin 1 alpha production

We investigated the role of interleukin 1 alpha (IL 1 alpha) in the pathogenesis of chronic liver disease. IL 1 alpha production by peripheral blood monocytes was measured with a specific, sensitive double-antibody radioimmunoassay. When monocytes were cultured for two days with bacterial lipopolysaccharide (LPS), IL 1 alpha production in asymptomatic hepatitis B virus carrier (ASC) and patients with chronic active hepatitis (CAH) was equivalent to that of controls (168 +/- 31 U/ml, mena +/- SD), while IL 1 alpha levels generated by monocytes from liver cirrhosis (LC) (117 +/- 45 U/ml, p less than 0.01) were significantly lower than controls. When normal monocytes were cultured together with LPS and IFN gamma, mena IL 1 alpha production was 297 +/- 56 U/ml. IL 1 alpha production in ASC did not differ from controls. On the other hand, IL 1 alpha production in patients with CAH (241 +/- 58 U/ml, p less than 0.05) and LC (189 +/- 70 U/ml, p less than 0.01) were significantly diminished in comparison with controls although there was considerable overlap. Serial study demonstrated that IL 1 alpha production rose significantly during acute deterioration of illness with marked rise in serum alanine aminotransferase. The addition of sera to normal monocytes cultures resulted in significantly enhanced suppression (p less than 0.05) for IL 1 alpha production in comparison with that of control sera. These findings indicate that decreased monocyte function and serum inhibitor(s) for IL 1 alpha production could contribute to the pathogenesis of chronic liver disease.

Pilot study of recombinant human alpha-interferon for chronic non-A, non-B hepatitis

Recombinant human alpha-interferon was administered to 15 patients with chronic non-A, non-B hepatitis as a part of a pilot study. Patients received injections of 2 million units per day of interferon three times weekly for 16 wk. The treatment schedule was completed in all but one, whose serum aminotransferase levels were continuously elevated during treatment. In seven of the 15 patients, elevated serum aminotransferase levels decreased rapidly during therapy and eventually fell into the normal or nearly normal range. However, once the therapy was stopped, a prompt return of aminotransferase levels to pretreatment values usually was observed. After 3 months of follow-up, aminotransferase activities remained normal in only two patients in whom liver histology showed marked improvement in intralobular degeneration and focal necrosis of hepatocytes. Anti-interferon antibody was detected in four patients at the end of therapy, and decreased 2',5'-oligoadenylate synthetase activity occurred in two patients and in another with relapsed aminotransferase level. Whether alpha-interferon therapy could control the disease activity in patients with chronic non-A, non-B hepatitis deserves further evaluation in a prospective controlled trial.

Prevalence of Non-alcoholic Fatty Liver Disease Detected by Computed Tomography in the General Population Compared with Ultrasonography

Objective To assess the prevalence and clinical correlates of non-alcoholic fatty liver disease (NAFLD) identified by computed tomography (CT) in the general population compared with ultrasonography (US). Methods Four hundred and fifty-eight subjects who received health checkups at Meijo Hospital in 2021 and underwent CT within a year of US in the past decade were analyzed. The mean age was 52.3±10.1 years old, and 304 were men. Results NAFLD was diagnosed in 20.3% by CT and in 40.4% by the US. The NAFLD prevalence in men was considerably greater in subjects 40-59 years old than in those ≤39 years old and in those ≥60 years old by both CT and US. The NAFLD prevalence in women was substantially higher in the subjects 50-59 years old than in those ≤49 years old or those ≥60 years old on US, while no significant differences were observed on CT. The abdominal circumference, hemoglobin value, high-density lipoprotein cholesterol level, albumin level, and diabetes mellitus were independent predictors of NAFLD diagnosed by CT. The body mass index, abdominal circumference, and triglyceride level were independent predictors of NAFLD diagnosed by the US. Conclusion NAFLD was found in 20.3% of CT cases and 40.4% of US cases among recipients of health checkups. An "inverted U curve" in which the NAFLD prevalence rose with age and dropped in late adulthood was reported. NAFLD was associated with obesity, the lipid profile, diabetes mellitus, hemoglobin values, and albumin levels. Our research is the first in the world to compare the NAFLD prevalence in the general population simultaneously by CT and US.

Interferon-gamma production specific for hepatitis B virus antigen by intrahepatic T lymphocytes in patients with acute and chronic hepatitis B

OBJECTIVES

Studies were undertaken to determine whether intrahepatic lymphocytes have a greater cellular immune response specific for hepatitis B virus (HBV) antigen than peripheral blood lymphocytes in HBV-infected man.

METHODS

HB nucleocapsid antigen-stimulated interferon-gamma (IFN-gamma) production of lymphocytes was measured in acute self-limited hepatitis (AH) (eight cases) and chronic hepatitis (CH) (14 cases).

RESULTS

In both patient groups, basal IFN-gamma levels without any stimulation were higher in the hepatic T cells than in the peripheral T cells. The values in cultures from blood and liver were larger in AH than in CH. Alternatively, IFN-gamma response to HBcAg and HBeAg was less in hepatic T cells than in the corresponding blood cultures; T cell response was HLA class II restricted. Cell flow cytometry study showed that in all patient groups, percentages of CD3+, CD8+, and HLA-DR+ cells were significantly greater in liver than in peripheral blood, whereas the proportion of hepatic CD4+ cells was decreased, compared with that in peripheral CD4+ cells.

CONCLUSIONS

These findings suggest that liver infiltrates are already activated in vivo to produce IFN-gamma, particularly in patients with AH. The changes in the proportion of lymphocyte subsets may be responsible for the altered IFN-gamma response of hepatic T cells.

The NAFLD Index: A Simple and Accurate Screening Tool for the Prediction of Non-Alcoholic Fatty Liver Disease

OBJECTIVE

Non-alcoholic fatty liver disease (NAFLD) is a common debilitating condition in many industrialized countries that increases the risk of cardiovascular disease. The aim of this study was to derive a simple and accurate screening tool for the prediction of NAFLD in the Japanese population.

METHODS

A total of 945 participants, 279 men and 666 women living in Hokkaido, Japan, were enrolled among residents who attended a health check-up program from 2010 to 2014. Participants with an alcohol consumption > 20 g/day and/or a chronic liver disease, such as chronic hepatitis B, chronic hepatitis C or autoimmune hepatitis, were excluded from this study. Clinical and laboratory data were examined to identify predictive markers of NAFLD.

RESULTS

A new predictive index for NAFLD, the NAFLD index, was constructed for men and for women. The NAFLD index for men = -15.5693+0.3264 [BMI] +0.0134 [triglycerides (mg/dl)], and for women = -31.4686+0.3683 [BMI] +2.5699 [albumin (g/dl)] +4.6740[ALT/AST] -0.0379 [HDL cholesterol (mg/dl)]. The AUROC of the NAFLD index for men and for women was 0.87(95% CI 0.88-1.60) and 0.90 (95% CI 0.66-1.02), respectively. The cut-off point of -5.28 for men predicted NAFLD with an accuracy of 82.8%. For women, the cut-off point of -7.65 predicted NAFLD with an accuracy of 87.7%.

CONCLUSION

A new index for the non-invasive prediction of NAFLD, the NAFLD index, was constructed using available clinical and laboratory data. This index is a simple screening tool to predict the presence of NAFLD.

Two novel mutations, L490R and V561X, of the transferrin receptor 2 gene in Japanese patients with hemochromatosis

BACKGROUND AND OBJECTIVES

The low prevalence of the C282Y mutation of the HFE gene in Japan means that the genetic background of hemochromatosis in Japanese patients remains unclear. In a previous report, we showed that 3 patients from one family had an AVAQ 594-597 deletion of the transferrin receptor (TfR2) gene. This suggests that the TfR2 gene is involved in hemochromatosis in Japanese patients.

DESIGN AND METHODS

Nine patients clinically diagnosed with hemochromatosis were included in the study. DNA was extracted from whole blood samples collected with informed consent. The HFE and TfR2 genes were analyzed by sequencing the coding region and splicing sites.

RESULTS

There were no mutations in the HFE gene. In the TfR2 gene, 2 novel mutations, 1469T->G (L490R) and 1665delC (V561X), were found in 2 patients. A known variation, 714C-> (I238M), was also found in the patient with L490R. The patient homozygous for both L490R and I238M presented with a mild manifestation of hemochromatosis at the age of 41 years. His liver was cirrhotic with parenchymal iron deposits and the result of a glucose tolerance test was compatible with diabetes mellitus. The patient homozygous for V561X had severe iron overload with the triad of cirrhosis, diabetes mellitus and skin pigmentation at the age of 58 years.

INTERPRETATION AND CONCLUSIONS

Taken together with the previous report, 5 of our 12 patients with hemochromatosis manifesting in middle age had mutations in the TfR2 gene. Thus, TfR2 plays a role in the pathogenesis of hemochromatosis in Japan.

Phenotypic expression of natural killer cell associated membrane antigens in patients with chronic liver disease and hepatocellular carcinoma

The function and phenotypes of peripheral blood natural killer (NK) cells from patients with chronic liver disease and hepatocellular carcinoma (HCC) were examined using a 4 hr 51Cr release NK assay and two-color flow cytometry utilizing anti-Leu-7 and anti-Leu-11 monoclonal antibodies. There was no significant difference between control and patient groups in the percent representation of a total of NK, Leu-7-11+ or Leu-7+11- cells except that the percent representation of Leu-7+11- cells was significantly increased in patients with liver cirrhosis (LC) in comparison with that of chronic active hepatitis (CAH). On the other hand, patients with LC and HCC had lower absolute numbers of a total of NK, Leu-7-11+ and Leu-7+11- cells than did controls or patients with CAH, reflecting the diminished peripheral blood lymphocyte count. Our data indicate that decreased in vitro NK activity in patients with LC and HCC observed in the present study may be due to a functional defect of NK cells.

Relative immunogenicity of hepatitis B virus-encoded antigens as targets for cytotoxic T-cell response

To analyse the immunological mechanism of hepatocellular injury in hepatitis B virus (HBV) infection, the immunoreactivity of HBV-encoded antigens as a target for cytotoxic T lymphocyte (CTL) response was examined using recombinant vaccinia virus (RVV) expressing surface protein (S), precore/core protein (PC), and core protein (C) of HBV. C3H/He mice (H-2k) were inoculated with each RVV. Their spleen cells were then harvested and stimulated in vitro with the histocompatible transfectant, which stably expressed hepatitis B surface antigen (HBsAg), hepatitis B e antigen (HBeAg), and hepatitis B core antigen (HBcAg), and used as effectors. As the targets, L cells (H-2k) infected with individual RVV were used. Cytotoxic test was performed with various combinations and ratios of effectors and targets. The reactivity of PC-primed effectors against PC-expressing targets was greatest with 71.4% specific lysis on average at an effector/target ratio of 12.5:1 among all the combinations. C-primed effectors against C-expressing target also revealed rather high cytotoxicity (specific lysis, 40.6% at an E/T ratio of 12.5:1). Furthermore, PC-primed and C-primed effectors showed a cross-reactivity to the targets expressing other nucleocapsid antigen, respectively. S-primed effectors showed less lytic activity against S-expressing targets (specific lysis, 18.4% at an E/T ratio of 12.5:1). The CTL responses were blocked by anti-CD8 and anti-major histocompatibility complex (MHC) class I antibodies, but not by anti-CD4 or anti-MHC class II. These findings suggest that endogenously synthesized nucleocapsid antigen, especially PC, is a dominant target for the MHC class I-restricted CTL in H-2k mice and that this system may work as an efficient model to study immunopathogenesis of HBV infection.

T cell lines reactive with hepatitis B core and E antigens in patients with chronic hepatitis B

Hepatitis B virus (HBV)-associated nucleocapsid antigen (HB core and HB e) is believed to be a major target for T cell-mediated hepatocellular damage in chronic HBV carriers. Studies were undertaken to determine whether both nucleocapsid Ag could be recognized by T cell lines from peripheral blood mononuclear cells (PBMC) from patients with chronic hepatitis B. After cultivation in the presence of rHBcAg or purified HBeAg, growing cells were cloned by limiting dilution in the presence of PHA, IL-2 and allogenic feeder cells. Four HBcAg-reactive and three HBeAg-reactive T cell lines from two patients were generated by proliferation assays. None of the cell lines responded to HB surface Ag or PPD. Four lines were of the CD8+ CD11b- cytotoxic phenotype, two of the CD4+ Leu8- helper phenotype, and the remaining one consisted of mixed populations of CD4+ Leu8+ and CD4+ Leu8- cells. Cross-reactivity study showed that a HBcAg-induced CD4+ T cell line responded to HBeAg, and similarly a HBeAg-induced CD8+ T cell line responded to HBcAg. The reactions were inhibited by HLA class II antibody, but not by class I Ab.

Recombinant human alpha-interferon therapy for chronic non-A, non-B hepatitis: second report

Four million units per day of recombinant human alpha-interferon were administered three times weekly for 16 wk to 26 patients with chronic non-A, non-B hepatitis. The efficacy of therapy was assessed by comparing it with the results in the nontreated patients, or with our previous study in which we administered 2 million units per day of interferon. The treatment was discontinued in four patients 8 wk after start of therapy because there was no improvement in serum aminotransferase levels. The remaining 22 patients completed the treatment schedule, and their aminotransferase values showed significant decreases throughout the therapy and during the follow-up period, compared with their baseline levels or the nontreated group. After 3 months of follow-up, normal aminotransferase activities were seen in eight treated patients. In four of these patients, liver histology showed a marked improvement in inflammation and parenchymal cell necrosis. Percent change from pretreatment level of serum 2',5'-oligoadenylate synthetase activity was significantly higher in the aminotransferase-normalized group than in the nonnormalized group during therapy. The present study suggested that a higher dose of alpha-interferon could control the disease activity more effectively in patients with chronic non-A, non-B hepatitis.