Kupffer cell hyperplasia in liver diseases. Demonstration by scanning electron microscopy of biopsy samples

Kupffer Cell Hyaline Globules in Children With Autoimmune Hepatitis

BACKGROUND

Hyaline globules (HGs) in the cytoplasm of Kupffer cells (KCs) have been appraised for being a typical feature of autoimmune hepatitis (AIH). This study aimed to determine how useful Kupffer cell hyaline globules (KCHGs) are in diagnosing AIH vs. other causes of pediatric chronic liver diseases (PCLDs).

MATERIALS AND METHODS

This retrospective study recruited 124 children; 58 with AIH, 50 with chronic hepatitis C virus (HCV) infection, and 16 with Wilson's disease (WD). Two pathologists retrieved paraffin blocks of liver biopsies and prepared new cut sections for Periodic acid-Schiff-Diastase (PAS-D) stain. They independently examined liver biopsies before starting treatment. Two pediatricians reviewed medical records for demographic, clinical, laboratory, and serological findings.

RESULTS

Females represented 48.6% of the studied children with a median age of 5.8 (4.9) years. Pathologists identified KCHGs in 67.24%, 12.5%, and 6.0% of AIH, WD, and HCV affected children respectively, P < 0.001. A significantly higher proportion of seropositive than seronegative AIH patients had KCHGs (77.5% vs. 50.0%), (P < 0.05). In multivariate analysis, KCHGs and prolonged prothrombin time were the only significant predictors that differentiate between AIH and the other studied PCLDs. The odds ratio of having AIH increased 68 times if KCHGs were seen. Among children with AIH, the presence of KCHGs was associated with higher median levels of direct bilirubin 2.2 (1.3) vs. 1.2 (2.2), and immunoglobulin G 3.2 (1.9) vs. 2.0 (1.7), (P < 0.05), but not to histopathological findings or hepatic fibrosis and activity.

CONCLUSIONS

KCHGs are key indicators that can differentiate between AIH and other PCLDs, and between seropositive and seronegative AIH.

Improved biopharmaceutical attributes of lumefantrine using choline mimicking drug delivery system: preclinical investigation on NK-65 P.berghei murine model

BACKGROUND

Lumefantrine (LMF) is first-line antimalarial drug, possesses activity against almost all human malarial parasites, but the in vivo activity of this molecule gets thwarted due to its low and inconsistent oral bioavailability (i.e. 4-12%) owing to poor biopharmaceutical attributes.

METHODS

Lumefantrine phospholipid complex (LMF-PC) was prepared by rota-evaporation method following job's plot technique for the selection of apt stoichiometric ratios. Docking studies were carried out to determine the possible interaction(s) of LMF with phosphatidylcholine analogue. Comparative in vitro physiochemical, solid-state characterization, MTT assay, dose-response on P. falciparum, in vivo efficacy studies including pharmacokinetic and chemosuppression on NK-65 P. berghei infected mice were carried out.

RESULTS

Aqueous solubility was distinctly improved (i.e. 345 times) with phospholipid complex of LMF. Cytotoxicity studies on Hela and fibroblast cell lines demonstrated safety of LMF-PC with selectivity indices of 4395 and 5139, respectively. IC₅₀ value was reduced almost 2.5 folds. Significant enhancement in C_max (3.3-folds) and AUC (2.7-folds) of rat plasma levels indicated notable pharmacokinetic superiority of LMF-PC over LMF suspension. Differential leukocytic count and cytokine assay delineated plausible immunoregulatory role of LMF-PC with nearly 98% chemosuppression and over 30 days of post-survival.

CONCLUSION

Superior antimalarial efficacy and survival time with full recovery of infected mice revealed through histopathological studies.

Quantitative analysis of activated Kupffer cells in viral hepatitis: application of computer image analysis for lectin histochemistry

Lectin histochemistry revealed that Kupffer cells in the normal liver bound lectins such as Concanavalin A (Con A), Ricinus communis agglutinin (RCA) and Wheat germ agglutinin (WGA), but did not bind Peanut agglutinin (PNA), Dolichos fibflorus agglutinin (DBA), Ulex europaeus agglutinin I (UEA-I) or Soybean agglutinin (SBA). Kupffer cells in viral liver diseases, however, bound the PNA lectin and the binding was specific to Kupffer cells in liver parenchyma. Computer image analysis was performed using light micrographs of sections stained with immunoperoxidase and diaminobenzidine (DAB). The dark brown area of reaction products was detected by analyzing each color component (red, green and blue) in the picture and was expressed as the percent area in the parenchyma. Quantitative analysis revealed the percent area occupied by Kupffer cells positive for the PNA lectin was as follows: acute hepatitis, 2.83 +/- 0.74; chronic persistent hepatitis, 2.51 +/- 0.88; chronic aggressive hepatitis, activity moderate and severe, 4.71 +/- 2.23 and 3.45 +/- 1.84; and liver cirrhosis, 1.96 +/- 0.99. The percent area of Kupffer cells was significantly higher in CAH2A than that in chronic persistent hepatitis or in liver cirrhosis. These results suggest that the PNA lectin could be used as a marker for activated Kupffer cells and that activated Kupffer cells were increased in volume in chronic aggressive hepatitis.

Drug-induced hepatic microgranulomatosis in cynomolgus monkeys

This report discusses a unique drug-induced hepatotoxicity in cynomolgus monkeys treated orally with a novel potassium sparing experimental diuretic, [2,6-bis(4-chlorophenyl)-4-pyridinecarboxylic acid]. Groups of 6 adult male and female monkeys were treated orally with vehicle diluent, modified vehicle #122 or a suspension of the drug at 5.0, 12.5, or 32.0 mg/kg/day for 2 weeks. Another group of 5 monkeys were treated orally with 25.0 mg/kg/day of the drug for 2 weeks. Disposition of the drugs was evaluated in 2 monkeys in the later group that received 27.4 mg/kg of radiolabelled drug on the 1st and last day of dosing. Hepatic toxicity was characterized biochemically, light and electron microscopically, histochemically, immunocytochemically, and toxico-kinetically. Conjugated serum bilirubin, alanine transaminase, and aspartate transaminase levels were increased in monkeys treated with over 12.5 mg/kg/day of the diuretic. The periacinar hepatic plates of monkeys treated with 25.0 or 32.0 mg/kg/day were distorted by accumulation of PAS and oil red-O positive multinucleated Kupffer cells. The cytosol of these cells was expanded by phagolysosomes containing granular materials of varying electron densities. Granular electron dense materials were also in endothelial cells and bile canaliculi. Fatty change, cholestasis, and rare piecemeal hepatic necrosis were minimal. The drug was primarily excreted through urine. Plasma concentration and half life of the drug were increased with multiple dosing. The highest concentration of unexcreted parent drug was in the liver. Drug-induced noninflammatory hepatic microgranulomatosis, apparently caused by sequestered drug-lipid/mucopolysaccharide complex in the phagocytic cells of the liver, can occur in any species, including humans, if orally administered xenobiotics are presented to the liver in particulate form.

Alterations in Fc receptor activity in sinusoidal endothelial cells and Kupffer cells during D-galactosamine (GalN)-induced liver injury in rats. A histological study

Fc receptors in sinusoidal cells and immune complex uptake were studied histologically in D-galactosamine HCl (GalN)-induced liver injury in rats. Kupffer cells and monocytes were distinguished from sinusoidal endothelial cells and from each other by endogenous peroxidase staining. Fc receptors were found along the sinusoidal endothelium throughout the lobules in normal livers. In acute injury caused by 300 or 750 mg/kg of GalN, Fc receptors were preserved within necrotic foci until the foci were infiltrated by inflammatory cells. The endothelial Fc receptor activity altered, as demonstrated by their capacity to bind immune complexes, after GalN injection. The activity decreased from 24 h after injection in the periportal areas in both dose groups, and increased transiently with dose-dependence in the remaining areas. Kupffer cell numbers also showed a transient dose-dependent increase, except in the periphery of lobules where they generally decreased. In chronic injury with 400 mg/kg, Fc receptors were lost and Kupffer cells decreased in the periportal areas. Circulating immune complexes were ingested by Kupffer cells and endothelial cells in normal and injured livers, showing the the same distribution as that of Fc receptors except that the complexes decreased gradually towards the centrilobular zones.

Kupffer cells modulate natural killer cell activity in vitro by producing prostaglandins

The effect of Kupffer cells on natural killer (NK) cell-mediated cytotoxicity was examined. Kupffer cells prepared from rat liver suppressed NK activity against K562 cells and other tumor cell lines through a soluble factor secreted into the culture supernatant. When human peripheral blood mononuclear cells were incubated with the Kupffer cell-culture supernatant, a significant reduction of the cytotoxic activity was observed in the 6-hr chromium-release assay. This activity was dose dependent and was evident at various effector/target cell ratios. Lipopolysaccharide stimulated generation of the suppressive factor released from Kupffer cells in a dose-dependent manner. Suppression of the NK activity was observed when the Kupffer cell-culture supernatant was present in the assay system, whereas pretreatment of effector/target cells with the supernatant had minimal inhibitory effects. Autologous monocytes in human peripheral mononuclear cells were not related to this suppression. The suppressive factor in the fraction had a molecular weight below 10,000. Indomethacin, an inhibitor of prostaglandin synthesis, ameliorated the suppressive effects. These results suggest that Kupffer cells may modulate NK activity by producing PGs (E1, E2, and F2 alpha).

Reduction of aspirin-induced fecal blood loss with low-dose misoprostol tablets in man

Misoprostol (SC-29333), a synthetic prostaglandin E1 methyl ester analog, was given simultaneously with acetylsalicylic acid in a double-blind, placebo-controlled randomized prospective study of 32 healthy human male subjects. Fecal blood loss was measured for eight days using the 51Cr-labeled red blood cell technique. Aspirin (650 mg qid) and misoprostol (25 micrograms qid) or placebo were given during days 3, 4, and 5. There was a significant (P less than 0.05) increase in median blood loss (modified Friedman test) from 0.81 to 6.05 ml/day in the aspirin with placebo group (N = 16). Median blood loss was increased (from 0.75 to 3.75 ml/day) in the aspirin with misoprostol group (N = 16), but this was significantly less (Mann-Whitney U test, P less than 0.01) than the placebo group. Mean serum salicylate concentrations in the placebo and misoprostol groups were similar (7.8 and 6.8 micrograms/ml, respectively). There were no significant changes in laboratory values in any of the subjects studied, nor were any major side-effects encountered. This study demonstrates that oral misoprostol reduces aspirin-induced gastrointestinal bleeding even when administered simultaneously and at a dose level below its threshold for significant acid inhibition. This indicates a potential role for misoprostol in the prevention of gastric mucosal damage in selected patients.