Prominent proliferative response of peripheral blood mononuclear cells to a recombinant non-structural (NS3) protein of hepatitis C virus in patients with chronic hepatitis C.

The proliferative response of peripheral blood mononuclear cells (PBMC) to a recombinant non-structural (NS3) protein of hepatitis C virus (HCV) was studied in 41 patients with chronic hepatitis C. Of them, 28 had chronic persistent hepatitis (CPH) and 13 chronic active hepatitis (CAH). The positive proliferation rate of PBMC to the recombinant NS3 protein, T9Ag, was 66% in the 41 patients (77% in CAH versus 61% in CPH; P > 0.05) when stimulation index (SI) = 4 was set as the cut-off value. However, mean SI of CAH patients was significantly higher than that of CPH patients (8.3 +/- 5.2 versus 5.1 +/- 3.6; P < 0.05). Six other chronic hepatitis patients who were repeatedly negative for anti-HCV antibody but positive for serum HCV RNA also had an SI of > or = 4.0. The frequency of cellular immune response to the T9Ag is among the highest results obtained by using HCV antigens tested so far. Our studies thus indicate that NS3 is an immunologically important region of HCV for T cells. Moreover, the proliferative response to T9Ag may help to establish hepatitis C etiology in chronic hepatitis patients who are seronegative with currently available anti-HCV assays.     

Increased tumour necrosis factor alpha production by neutrophils in patients with hepatitis B.

AIMS--To investigate the role of serum and neutrophil tumour necrosis factor alpha (TNF alpha) in patients with viral hepatitis. METHODS--The activities of serum and neutrophil TNF alpha were measured using a bioassay of in vitro cytotoxicity against L929 cells in 57 patients with viral hepatitis and 20 healthy blood donors. RESULTS--Both serum and neutrophil TNF alpha in patients with chronic active hepatitis (CAH) and subacute fulminant hepatitis (SAFH) increased compared with those in normal controls (p < 0.01). No such differences were seen in patients with acute hepatitis. Serum and neutrophil TNF alpha were obviously reduced in patients with CAH and SAFH during convalescence compared with the active period (p < 0.05; p < 0.01). Furthermore, serum TNF alpha was significantly increased in patients with SAFH and complications compared with those without (p < 0.01), and in patients with SAFH who died compared with those who survived (p < 0.01). Neutrophil TNF alpha was significantly higher in patients with SAFH and secondary bacterial infections (p < 0.05). CONCLUSIONS--Production of serum and neutrophil TNF alpha is increased in patients with CAH and SAFH, suggesting that neutrophil TNF alpha causes liver injury in these patients.     

The degrees of hepatocyte nuclear but not cytoplasmic expression of hepatitis B core antigen reflect the level of viral replication in chronic hepatitis B virus infection.

Although immunodetection of hepatitis B core antigen (HBcAg) in the liver has long been recognized as a marker of active hepatitis B virus (HBV) replication, the correlation between the level of viral replication and the degrees of expression of HBcAg in hepatocytes remains to be established. In this study, we examined the semiquantitative relationship between the level of HBV DNA in serum and the degree of expression of HBcAg in the hepatocyte nucleus or cytoplasm in 80 adults with chronic hepatitis B. Expression of HBcAg in hepatocytes was studied by the avidin-biotin immunoperoxidase method, and the results were scored on a scale of 0 to 4, values corresponding to the positivity of 0, 1 to 10, 11 to 25, 26 to 50, and > 50%, respectively, of hepatocytes examined. Serum HBV DNA was tested by a liquid hybridization assay, and the results were scored on a scale of 0 to 5, values corresponding to undetectable levels and levels of < or = 50, 51 to 100, 101 to 150, 151 to 200, and > 200 pg/ml, respectively. The results revealed a highly significant, positive correlation between the level of HBV DNA in serum and the degree of expression of HBcAg in nuclei (Spearman rank correlation coefficient [rs] = 0.653, P < 0.001). The mean scores (95% confidence intervals) of levels of HBV DNA in sera of patients whose levels of expression of HBcAg in nuclei received a score of 0 (n = 33), 1 or 2 (n = 35), and 3 or 4 (n = 12) were 1.3 (1.1 to 1.5), 2.5 (2.1 to 2.9), and 3.9 (3.1 to 4.7), respectively. However, no correlation between the level of HBV DNA in serum and the degree of expression of HBcAg in the cytoplasm was noted (rs = 0.026, P > 0.8). In conclusion, the degree of expression of HBcAg in the hepatocyte nucleus but not the cytoplasm can accurately reflect the level of viral replication in patients with chronic hepatitis B.     

Increased expression of intercellular adhesion molecule-1 (ICAM-1) in a murine model of pulmonary eosinophilia and high IgE level.

T lymphocytes and eosinophils are probably involved in the pathogenesis of allergic bronchopulmonary aspergillosis (ABPA), a disease characterized by pulmonary eosinophilia and high serum and lavage IgE levels. We recently developed a murine model of ABPA. To investigate the mechanisms of T lymphocyte and eosinophil recruitment to the lung in this disease, we examined the expression of ICAM-1 in the lung tissue of mouse challenged with Aspergillus fumigatus (Af) antigen. C57B1/6 mice were intranasally exposed to Af (Af group) or saline (control group) three times a week for 1, 2 or 3 weeks. On days 4, 7, 14 and 21, mice were killed and lung tissue was fixed in acetone and embedded in glycol methacrylate. Serial 2-microns sections were stained with chromotrope 2R and MoAbs against ICAM-1, CD11a/CD18 (LFA-1) and CD3. Af-challenged mice presented significant increases in eosinophil, T lymphocyte and LFA-1-positive cell count and up-regulated expression of ICAM-1 in the lung tissue at all the time points examined. ICAM-1 expression intensity correlated with the number of T lymphocytes (r = 0.59, P < 0.01), LFA-1-positive cells (r = 0.68, P < 0.001), but not of eosinophils (r = -0.24, P > 0.05). These findings suggest that up-regulation of ICAM-1 expression is involved in the inflammatory process of this murine model of ABPA, and that this up-regulation may be more relevant to the the T lymphocyte accumulation in the lung.     

Quantitative histoenzymological studies in the diagnosis of chronic viral hepatitis

The examination has involved 89 patients with chronic viral hepatitis, aged 14 to 59, 68 male and 21 female ones. Thirty-two (36.0%) patients suffered from chronic viral hepatitis B. Life-time biopsy of the liver was performed in all the cases. Chronic persistent hepatitis (CPH) has been diagnosed in 39 patients, chronic active one (CAH) in 50. Histochemical examinations of the biopsy specimens included measurements of alkaline phosphatase (AP) by the azocompound method, of 5-nucleotidase (5-Nuc) by the Ca-Co method, and of hepatocyte pigments. Stereologic methods were used in morphometric analysis of the area of sinusoids active for AP and 5-Nuc enzymes and of the intracellular pigment level with consideration for their distribution in the hepatic lobe. The findings evidence a significant increase of the area of sinusoids active for AP and 5-Nuc in CAH patients, in contrast to those with CPH, but the latter group has developed much higher levels of hepatocyte pigments. These data may be useful to specify the activity of chronic viral hepatitis in cases with poorly representative biopsy specimens.     

ICAM-1/LFA-1 interactions in T-lymphocyte activation and adhesion to cells of the blood-retina barrier in the rat.

To identify the signals involved in the adhesion and subsequent migration of lymphocytes across the endothelium (REC) and pigment epithelium (RPE) of the blood-retina barrier we have studied the effects of monoclonal antibodies (mAb) to rat adhesion/accessory molecules on the binding of normal and concanavalin A (Con A)-activated rat spleen lymphocytes to cultured unstimulated and interferon-gamma (IFN-gamma)-stimulated RPE and REC. Forty to 48% of unactivated T cells were found to bind to normal REC or RPE by leucocyte function-associated antigen-1/intercellular adhesion molecule-1 (LFA-1/ICAM-1)-independent mechanisms, despite constitutive expression of ICAM-1 by the RPE cells and LFA-1 by the T cells. Con A-activated lymphocytes showed an enhanced adhesion to both RPE and REC. However, IFN-gamma-stimulated RPE and REC did not demonstrate a significant increase in adhesiveness for normal lymphocytes highlighting the importance of lymphocyte integrin activation from low-affinity to high-affinity state. Activated lymphocyte adhesion to unstimulated RPE and REC was significantly blocked by LFA-1 mAb (35%, P < 0.0001) and ICAM-1 mAb (20%, P < 0.001). Inhibition of adhesion by antibody to CD2 was not significant. Both ICAM-1 and LFA-1 mAb also significantly (P < 0.05) blocked antigen presentation following retinal extract stimulation of lymphocytes from immunized rats in proliferation assay. These data suggest that the ICAM-1/LFA-1 system is important in lymphocyte trafficking into the eye only after lymphocyte activation.     

Elevated expression in situ of selectin and immunoglobulin superfamily type adhesion molecules in retroocular connective tissues from patients with Graves' ophthalmopathy.

Activation of certain adhesion molecules within vascular endothelium and the surrounding extravascular space is a critical event in the recruitment and targeting of an inflammatory response or autoimmune attack to a particular tissue site. We have recently demonstrated that the adhesion of lymphocytes to cultured retroocular fibroblasts obtained from patients with Graves' ophthalmopathy (GO) is mediated predominantly by the interaction of lymphocyte function-associated antigen-1 (LFA-1), expressed on lymphocytes, with intercellular adhesion molecule-1 (ICAM-1), expressed by these cells following exposure to interferon-gamma (IFN-gamma), tumour necrosis factor-alpha (TNF-alpha), IL-1 alpha or purified thyroid-stimulating immunoglobulins. We now report the expression and localization in situ of several adhesion molecules, ICAM-1, endothelial leucocyte adhesion molecule-1 (ELAM-1), vascular cell adhesion molecule-1 (VCAM-1), and LFA-3 in retroocular tissues derived from patients with severe GO (n = 4) and normal individuals (n = 3). Serial cryostat sections of tissue specimens were processed for immunoperoxidase staining using various MoAbs against ICAM-1, ELAM-1, VCAM-1 and LFA-3. In addition, consecutive sections were stained with MoAbs against LFA-1, CD45RO (UCHL-1)DR-human leucocyte antigen (HLA-DR), CD11b/CD18 (Mac-1), and CD11c/CD18 (p150,95). In GO-retroocular tissues, strong immunoreactivity for ICAM-1 and LFA-3 was detected in blood vessels (> 90%), in perimysial fibroblasts surrounding extraocular muscle fibres, and in connective tissue distinct from extraocular muscle. No ICAM-1 or LFA-3 immunoreactivity was present in extraocular muscle cells themselves. ICAM-1 and LFA-3 immunoreactivity in normal tissues was minimal or absent both in connective and muscle tissues. Vascular endothelium was strongly positive for ELAM-1 and VCAM-1 in GO-retroocular tissues, while VCAM-1 immunoreactivity was minimal (< 5% of blood vessels) and ELAM-1 immunoreactivity was generally absent in normal retroocular tissue. LFA-1-expressing, activated mononuclear cells and memory T lymphocytes (CD3+/CD45RO+) were only detected in GO-retrocular tissues, and were mainly localized around blood vessels and in areas of ICAM-1-expressing connective and perimysial tissue. HLA-DR expression was restricted to GO-tissue specimens, with strong immunoreactivity detected in blood vessels, macrophages and connective tissue and perimysial fibroblasts. No HLA-DR was detectable in extraocular muscle cells. In conclusion, infiltration of the orbit in GO by mononuclear cells, and their targeting within the orbit, may depend upon the coordinate expression of certain adhesion and MHC molecules.(ABSTRACT TRUNCATED AT 400 WORDS)     

ICAM-1, soluble-CD23, and interleukin-10 concentrations in serum in renal-transplant recipients with Epstein-Barr virus reactivation.

Primary and reactivated Epstein-Barr virus (EBV) infections after organ transplantation are associated with the development of posttransplant lymphoproliferative malignancies. Since viral reactivation frequently stays asymptomatic, early diagnosis and treatment are challenges during posttransplant patient monitoring. Both soluble-CD23 (sCD23) and intercellular adhesion molecule 1 (ICAM-1) cell surface expression as well as interleukin-10 (IL-10) production are closely associated with viral gene expression. Therefore, immunoglobulin M (IgM), IgG, IgA, sCD23, ICAM-1, and IL-10 concentrations were measured in serum samples from patients during EBV reactivation (n = 14) and were compared with those in samples from patients without EBV reactivation (n = 10) following renal transplantation. In addition, serum sCD23, ICAM-1, and IL-10 concentrations were measured longitudinally in weekly to biweekly samples from 10 patients with EBV reactivation for at least 20 weeks following transplantation. A significant elevation of sCD23 was found during viral reactivation (P < 0.05), whereas ICAM-1 levels showed a nonsignificant increase. The finding of a highly significant elevation of the serum IL-10 concentration during EBV reactivation (P < 0.001) may support speculations about its role in EBV-induced lymphoproliferation and in the development of opportunistic infections and secondary malignancies. Maximum serum IL-10 levels at the time of EBV reactivation were found in 7 of 10 patients. Well-defined ICAM-1 and sCD23 concentration peaks were found in 9 of 10 and 8 of 10 patients, respectively. Although both markers are not specific for EBV reactivation and therefore may not be useful for primary diagnosis, sCD23 and ICAM-1 might be potent tools for the clinical monitoring of EBV activity and virus-induced lymphoproliferation.     

Immunohistological study of intrahepatic expression of hepatitis B core and E antigens in chronic type B hepatitis.

AIMS: To study the intrahepatic expression of hepatitis B virus (HBV) nucleocapsid antigen; and to determine the differential distribution of hepatitis B core and E antigens in chronic hepatitis B. METHODS: Hepatocyte expression of HBV nucleocapsid antigen was studied using rabbit anti-HBc, directed against both HBcAg and HBeAg; differential distribution of HBcAg and HBeAg was studied using murine monoclonal anti-HBc and anti-HBe in 120 patients with chronic hepatitis B. RESULTS: HBV nucleocapsid antigen was detected in 14 of 16 (87.5%) HBeAg seropositive patients with chronic persistent hepatitis (CPH), and in 54 of 64 (84.4%) HBeAg seropositive patients with chronic active hepatitis (CAH). Nuclear expression of nucleocapsid antigen was more prevalent in patients with CPH than in those with CAH; this was reversed in terms of exclusive cytoplasmic expression of nucleocapsid antigen (p < 0.05). Of 45 patients with nucleocapsid antigen in the nucleus, samples from 44 (97.8%) and 17 (37.8%) stained positively with monoclonal anti-HBc and anti-HBe, respectively. Of 65 patients with cytoplasmic nucleocapsid antigen, samples from 61 (93.8%) and 57 (87.7%) stained positively with monoclonal anti-HBc and anti-HBe, respectively. CONCLUSIONS: HBV nucleocapsid antigen is more prevalent in HBeAg positive patients with CPH than in those with CAH. Cellular expression of HBcAg and HBeAg in the cytoplasm is more or less the same; in the nucleus HBcAg exceeds HBeAg expression.     

人慢性肝炎贮脂细胞超微形态的计量学变化

目的探讨人慢性肝炎贮脂细胞（又称肝星状细胞）的转化规律。方法利用肝穿刺活检材料，以半薄切片光镜计数及电镜形态计量学等研究方法，对人慢性迁延性肝炎（５例）、轻度慢性活动性肝炎（５例）、中度慢性活动性肝炎（６例）及重度慢性活动性肝炎（５例）的肝小叶非纤维化区和正常肝组织（８例）的贮脂细胞数量、形态及细胞器含量变化进行观察分析。结果慢性活动性肝炎组肝小叶非纤维化区内贮脂细胞总数（２８．８０±３．９６、２７．１１±３．９６、２７．２０±８．８５）个／２０００００μｍ２明显低于正常肝组（４４．７５±６．８７）个／２０００００μｍ２及慢性迁延性肝炎组（４２．４０±１０．７６）个／２０００００μｍ２；过渡细胞的百分率随病变程度加重而趋向升高；部分贮脂细胞转化为成纤维细胞。结论慢性病毒性肝炎致肝纤维化过程中，贮脂细胞不断向成纤维细胞转化，并有向肝小叶纤维间隔迁移的趋势     

Serum inhibitory factors (SIF) in patients with acute and chronic hepatitis and their clinical significance.

Serum inhibitory factors (SIF) were demonstrated in a follow-up study in eighteen patients with HBSAg-positive viral hepatitis, in nine patients with chronic persistent hepatitis (CPH) and in six patients with progressive viral hepatitis (CAH). In addition these factors were studied in fifteen patients with HBSAg-positive and HBSAg-negative CAH. SIF appeared during the incubation period up to 4 weeks before onset and disappeared in most instances within 4 weeks after onset of jaundice. Sera from patients with CPH showed no marked inhibitory activity when studied over a period of up to 3 years as compared to patients with a progressive course of hepatitis. The presense of SIF may depend upon persistence of virus, and may help to predict the development of chronic hepatitis.     

Hemorheological Alteration in Patients Clinically Diagnosed with Chronic Liver Diseases

Since liver function is changed by chronic liver diseases, chronic liver disease can lead to different hemorheological alterations during the course of the progression. This study aims to compare alterations in whole blood viscosity in patients with chronic liver disease, focusing on the gender effect. Chronic liver diseases were classified into three categories by patient’s history, serologic markers, and radiologic findings: nonalcoholic fatty liver disease (NAFLD) (n = 63), chronic viral hepatitis B and C (n = 50), and liver cirrhosis (LC) (n = 35). Whole blood viscosity was measured by automated scanning capillary tube viscometer, while liver stiffness was measured by transient elastography using FibroScan®. Both systolic and diastolic whole blood viscosities were significantly lower in patients with LC than NAFLD and chronic viral hepatitis (P < 0.001) in male patients, but not in female patients. In correlation analysis, there were inverse relationships between both systolic and diastolic whole blood viscosity and liver stiffness (systolic: r = −0.25, diastolic: r = −0.22). Whole blood viscosity was significantly lower in male patients with LC than NAFLD or chronic viral hepatitis. Our data suggest that whole blood viscosity test can become a useful tool for classifying chronic liver disease and determining the prognosis for different types of chronic liver diseases.     

Comparison of cell adhesion molecule expression in cutaneous leucocytoclastic and lymphocytic vasculitis.

AIMS--To compare the expression of the cell adhesion molecules intercellular adhesion molecule-1 (ICAM-1), ELAM-1 (E-selectin), and vascular cell adhesion molecule-1 (VCAM-1) in cutaneous leucocytoclastic and lymphocytic vasculitis. METHODS--Immunohistochemical analysis was performed on early lesional skin biopsy specimens of leucocytoclastic vasculitis (n = 14), lymphocytic vasculitis (n = 10), non-lesional skin (n = 12), and normal skin (n = 5). A standard immunoperoxidase technique was used to detect expression of ICAM-1, E-selectin, VCAM-1, and the cell markers CD11a, CD11b, CD11c, von Willebrand factor, CD3, CD68, and neutrophil elastase (NP57). RESULTS--Basal keratinocyte intercellular adhesion molecule-1 was expressed in eight (80%) cases of lymphocytic and in only one (7%) case of leucocytoclastic vasculitis, and not in non-lesional skin or control biopsy specimens from normal subjects. E-selectin was expressed on vascular endothelium in eight (57%) cases of leucocytoclastic and in seven (70%) cases of lymphocytic vasculitis. Endothelial vascular cell adhesion molecule-1 expression was seen in three (21%) biopsy specimens of leucocytoclastic and five (50%) of lymphocytic vasculitis. There were increased numbers of cells in the dermal infiltrate stained for NP57, CD11b, and CD11c in leucocytoclastic compared with lymphocytic vasculitis (p < 0.001, p = 0.013, p = 0.009, respectively); immunoreactive positive cells for CD3 and CD11a were increased in lymphocytic compared with leucocytoclastic vasculitis (p < 0.001, p = 0.011, respectively). CONCLUSIONS--These observations indicate that upregulation of adhesion molecule expression occurs in both leucocytoclastic and lymphocytic vasculitis. The different patterns of adhesion molecule expression in the two groups of vasculitis may reflect differences in the local release of cytokines. In particular, detection of intercellular adhesion molecule-1 expression by keratinocytes in lymphocytic vasculitis is consistent with an active role for mediators derived from T lymphocytes in the pathogenesis of the lesion.     

Prognostic relevance of Period1 (Per1) and Period2 (Per2) expression in human gastric cancer

Period1 (Per1) and Period2 (Per2) are members of the circadian genes. Mounting evidence suggests that the deregulation of the circadian clock plays an important role in the development of mammalian cancer. However, the expression and clinical significance of Per1 and Per2 in gastric cancer is still unexplored. Here, we evaluated the expression pattern of Per1 and Per2 in 246 gastric cancer specimens and their adjacent, non-tumorous tissues using immunohistochemical assays. Per1 expression was significantly associated with clinical stage (p < 0.001), depth invasion (p < 0.001), lymph node metastasis (p < 0.001) and pathologic differentiation (p < 0.001). On the other hand, Per2 was associated with clinical stage (p = 0.021) and depth invasion (p = 0.007). Per1 expression was positively correlated with Per2 expression in the 246 gastric cancer patients (r = 0.378, p < 0.001), and the expression levels of Per1 and Per2 were down-regulated in gastric cancer tissues when compared with adjacent, non-tumorous tissues in 45 gastric cancer samples (p < 0.001, p = 0.003). Patients with lower Per1 and Per2 tumor expression had a shorter survival time than those with higher expression. Univariate and Multivariate analyses indicated that Per2 expression is an independent prognostic factor (p = 0.023). Our results demonstrate that Per1 and Per2 may play important roles in tumor development, invasion and prognosis, and Per2 may serve as a novel prognostic biomarker of human gastric cancer.     

Membrane staining for hepatitis B surface antigen on hepatocytes: a sensitive and specific marker of active viral replication in hepatitis B.

AIMS--To test the hypothesis that membranous staining of hepatitis B surface antigen (HBsAg) on the hepatocyte is a marker of active viral replication in chronic hepatitis B virus (HBV) infection. METHODS--Intrahepatic expression of HBsAg and hepatitis B core antigen (HBcAg) was studied by indirect immunofluorescence on frozen sections of liver specimens from 75 patients with chronic hepatitis B, and the results were correlated with serum levels of HBV-DNA assayed by spot hybridisation. RESULTS--Hepatocyte HBcAg was detected in all of 20 patients with serum levels of HBV-DNA > 1000 pg/ml, 18 (75%) of 24 patients with levels of HBV-DNA < or = 1000 pg/ml, and two (6.5%) of 31 patients without detectable serum HBV-DNA. The concordance between hepatocyte HBcAg and serum HBV-DNA was 89.3% (67/75). There were six patients (8%) who had detectable serum HBV-DNA but without hepatocyte HBcAg, and two patients (2.7%) who had detectable hepatocyte HBcAg but without serum HBV-DNA. Membranous staining of HBsAg associated with variable degrees of cytoplasmic HBsAg was found in all but one of 44 patients with serum HBV-DNA, irrespective of the levels, but in none of the 31 patients without serum HBV-DNA. Of the latter, HBsAg was distributed solely in the cytoplasm. In addition, there is an inverse correlation between serum levels of HBV-DNA and the degrees of cytoplasmic staining of HBsAg. The concordance between membranous staining fo HBsAg and serum HBV-DNA was 98.7% (74/75), significantly higher than that between hepatocyte HBcAG and serum HBV-DNA. CONCLUSIONS--Membranous staining of HBsAg on the hepatocyte correlated excellently with serum HBV-DNA and thus can be recognised as a sensitive and specific marker of active hepatitis B virus replication.     

Adhesion molecule monoclonal antibodies inhibit experimental autoimmune thyroiditis.

To examine the role played by adhesion molecules in thyroid autoimmunity, we have assessed the effect of administering monoclonal antibodies (mAb) against intercellular adhesion molecule-1 (ICAM-1) and lymphocyte function-associated antigen-1 (LFA-1) in experimental autoimmune thyroiditis, induced by immunizing rats with thyroglobulin in complete Freund's adjuvant. The antibody against LFA-1, but not against ICAM-1, reduced thyroglobulin antibody production (P < 0.01) and both antibodies caused a significant reduction (P < 0.002) in the severity of the thyroidal lymphocytic infiltration. In vitro, both mAb impaired the proliferative response of splenic and lymph node T cells to thyroglobulin, but only the antibody against LFA-1 reduced thyroid cell killing assessed using splenic lymphocytes as effectors. Monoclonal antibodies against both these adhesion molecules appear to inhibit cell-mediated autoimmunity in vivo, but only the LFA-1 mAb reduced the autoantibody response.     

Antibodies against human liver-specific protein (LSP) in acute and chronic viral hepatitis types A, B and non-A, non-B

Sera from 42 patients with acute viral hepatitis (AVH), 97 patients with chronic active liver disease (CALD) and 89 controls were tested by radioimmunoprecipitation for the presence of antibodies against human liver-specific protein (LSP). Anti-LSP were found in all but one patient with AVH type A (93%) and in a smaller percentage of AVH type B (55%). In non-A, non-B cases, anti-LSP were found in low percentages: 27% in acute cases, 10% in chronic cases. Furthermore, in CALD, a significant difference was found between HBsAg-positive CAH and 'autoimmune' CAH, a significant difference was found between HBsAg-positive CAH and 'autoimmune' CAH, both in anti-LSP prevalence (21%, 67%; P less than 0.005) and in anti-LSP titre (1:154 +/- 170, 1:316 +/- 186; P less than 0.005). In HBsAg-negative/anti-HBc-positive CAH, three of 15 patients were anti-LSP positive. Anti-LSP were found only in three of 57 patients with various non-hepatic diseases with autoimmune features. None of the 12 healthy HBsAg carriers was positive. Hence there is evidence for a considerable heterogeneity in anti-LSP response in acute and in chronic inflammatory HBsAg-negative liver diseases. These data suggest that anti-LSP antibodies do not play a prominent role in the process of transition to chronicity of acute viral hepatitis particularly in non-A, non-B cases, whereas these antibodies may be important in the mechanism of ongoing liver cell injury in patients with 'autoimmune' CAH, and can represent a useful diagnostic marker of this type of hepatitis.