Isabel Ojanguren

Cytomegalovirus infection in patients with inflammatory bowel disease

OBJECTIVE: It has been suggested that, in inflammatory bowel disease, cytomegalovirus behaves in the intestine as a nonpathogenic bystander, and even its finding in intestinal mucosa has unclear clinical relevance. We report our experience with a small series of patients with refractory inflammatory bowel disease and cytomegalovirus infection and their clinical outcome. METHODS AND RESULTS: Nine patients with moderate-severe attacks of inflammatory bowel disease did not respond to i.v. prednisone (1 mg/kg/day) for a mean of 24 days. Four of these patients were further treated with i.v. cyclosporine A (4 mg/kg/day). Cytomegalovirus infection was diagnosed in two patients after resection for treatment failure. In the remaining patients, cytomegalovirus infection was diagnosed in endoscopic mucosal biopsies and i.v. ganciclovir was then administered at a dose of 10 mg/kg/day for 2-3 wk. Five of these patients went into clinical remission, allowing corticosteroid and cyclosporine A discontinuation. Follow-up biopsies were performed and in all cases cytomegalovirus could not be detected in the colonic tissue. Two patients needed to be treated with intravenous cyclosporine A after antiviral therapy because of persistence of clinical symptoms despite the elimination of cytomegalovirus infection. CONCLUSIONS: Cytomegalovirus infection may play a role in the natural history of refractory inflammatory bowel disease and in some of its complications. The clearance of cytomegalovirus in colonic mucosa may lead some of these patients to remission.

Cytomegalovirus infection in ulcerative colitis: A prospective, comparative study on prevalence and diagnostic strategy

Background: Cytomegalovirus (CMV) infection has been reported in ulcerative colitis (UC), especially in severe, steroid‐refractory disease. However, its role in steroid‐refractoriness remains unknown. Our goals were to evaluate the prevalence of CMV disease in UC, the best diagnostic strategy, and the influence of disease activity and/or treatment in its development. Methods: Prospective, observational study including 114 subjects with active UC requiring intravenous steroids, steroid‐refractory UC, inactive UC on mesalamine, inactive UC on azathioprine, and healthy controls. CMV antibodies, pp65‐antigenemia, and rectal biopsies for hematoxylin and eosin staining, immunohistochemistry, and CMV‐pp67 mRNA were performed. These procedures were repeated after medical treatment only in patients with active UC. CMV disease was defined by the presence of inclusion bodies and/or positive immunohistochemistry in colonic biopsies. Results: CMV disease was found in 6 steroid‐refractory, CMV‐IgG‐positive UC patients but not among controls, inactive UC, or steroid‐responding UC patients. In 5 out of the 6 patients, CMV disease was diagnosed after 7–10 days on cyclosporine. Conclusions: CMV disease in UC only affects seropositive, steroid‐refractory UC patients. Steroid/cyclosporine treatment together with disease activity may predispose to latent colonic CMV reactivation. The impact of antiviral therapy on the clinical outcome of these patients remains to be elucidated.

Bacterial translocation in cirrhotic rats. Its role in the development of spontaneous bacterial peritonitis.

Bacterial translocation occurs in ascitic cirrhotic rats, but its association with ascites infection is unknown. The aim of this study was to assess the relation between bacterial translocation and ascites infection in cirrhotic rats. Male Sprague-Dawley rats were induced to cirrhosis with intragastric CCl4. Ascitic fluid, portal and peripheral blood, mesenteric lymph nodes, liver and spleen samples were cultured before death in those cirrhotic rats with less (group A) or more (group B) than 250 polymorphonuclear neutrophils/mm3 in ascitic fluid, as well as in healthy control rats. Histological examination of jejunum, ileum, and caecum was also performed. Bacterial translocation occurred in 45% of ascitic rats (without differences between groups A and B), but in 0% controls (p = 0.01). Bacterial translocation was associated with positive ascitic fluid culture in 60% of the cases. In all of them the same bacterial species was isolated in both mesenteric lymph node and ascitic fluid. Submucosal caecal oedema (100%), ileal lymphangiectasia (41%), and caecal inflammatory infiltrate (41%) occurred in ascitic rats, the last being associated with ascitic fluid positive culture (p = 0.04). These results suggests that bacterial translocation occurs frequently in ascitic cirrhotic rats, and may play a permissive, but not unique, part in a number of ascites infections. Whether histological changes seen in cirrhotic ascitic rats favour bacterial translocation remains to be elucidated.

Antimalarial myopathy: an underdiagnosed complication? Prospective longitudinal study of 119 patients

Objectives: To evaluate the prevalence and incidence of antimalarial myopathy in patients with rheumatic diseases treated with antimalarial drugs. Methods: Over a three year period, all patients with rheumatic diseases who were taking antimalarial drugs were studied. Serum muscle enzymes were assessed at the time of inclusion and every six months thereafter. Muscle strength, electromyography (EMG), and muscle biopsy were assessed in patients with a persistent muscle enzyme disturbances. Results: 119 patients were included (111 chloroquine, eight hydroxychloroquine). Of these, 22 (18.5%) had a persistent muscle enzyme disturbance: lactate dehydrogenase 19/22 (86%); creatine kinase 7/22 (32%), and aldolase 3/22 (14%). Findings of antimalarial myopathy were detected in 3/15 biopsied patients (20%) by light microscopy and in all 15 by electron microscopy. Eleven patients had myopathy at the time of inclusion (prevalence 9.2%) and four patients developed muscle injury during follow up (annual incidence 1.2%). Muscle weakness was observed in 8 of 15 patients with biopsy proven myopathy, giving a prevalence of clinical antimalarial myopathy of 6.7%. All these patients also had a myopathic pattern on electromyography. Conclusions: The prevalence of antimalarial myopathy is higher than previously recognised when muscle enzyme determination is used as a screening method. When a persistent muscle enzyme disturbance is observed, clinical and electromyographic studies should be undertaken periodically to detect the development of clinical myopathy. In cases of clinical myopathy, an anatomical-pathological tissue study, including an ultrastructural study, is mandatory to confirm the diagnosis.

Evolution of foamy macrophages in the pulmonary granulomas of experimental tuberculosis models

The chronic phase of Mycobacterium tuberculosis infection in mouse experimental models is characterized by the accumulation of foamy macrophages (FM)--which shape the outer ring of the granuloma - in the alveolar spaces, as detected in paraffin-embedded tissues stained with hematoxylin-eosin. In this study, the use of semi- and ultra-thin sections offers more detailed information about the origin of FM both in mouse and guinea-pig experimental models. Lipid bodies (LB) are present in macrophages from the beginning of infection and accumulate in the chronic phase. LB progress from an early (ELB) to a late (LLB) stage, defined according to their progressive capacity to generate cholesterol crystals, resembling atherosclerotic lesions. FM arise from massive accumulation of LLB. Electronic microscopy reveals intracellular lipophilic inclusions (ILIs) in those M. tuberculosis bacilli inside FM. It is our hypothesis that the accumulation of lipids in M. tuberculosis concomitant to the establishment of the non-replicating state prepares the bacilli for future reactivation and for facing future stressful environments.

Protease inhibitor-containing regimens compared with nucleoside analogues alone in the suppression of persistent HIV-1 replication in lymphoid tissue.

OBJECTIVE Lymphoid tissue provides a reservoir where HIV can persist. However, therapies incorporating a protease inhibitor can target this reservoir. This study was designed to investigate the relative long-term effects on lymph-node viral load and cellular architecture of regimens containing multiple nucleosides alone or in combination with protease inhibitors. METHODS Axillary lymph-node biopsies from 12 patients with undetectable viraemia (viral load < 20 copies/ml: mean CD4 cells 525 x 10(6)/l) for a mean period of 25 months (range, 10-52 months) were investigated for the presence of HIV by in situ hybridization and coculture. Four patients were receiving multiple nucleoside analogues alone or in one case with a suboptimally dosed protease inhibitor (group I). Protease inhibitor was added to the regimen of seven patients at least 6 months prior to lymph-node biopsy (group II). Standard flow cytometry and virological data were obtained from peripheral blood every 3 months. RESULTS By in situ hybridization, more productively infected CD4+ T cells were found in the lymph nodes of group I patients treated with nucleoside analogues alone. Very low numbers of productively infected lymph node cells were detected in the protease inhibitor-treated group II. No trapping of virions on the follicular dendritic cell (FDC) network was detectable in protease inhibitor-treated patients. In contrast, large deposits of FDC-bound virions were observed in three out of five patients from group I. Virus cultures from lymph node cells were positive in these three group I patients compared with only one out of seven patients from group II. Sequencing reverse transcriptase and protease genes from these isolates revealed typical mutations conferring resistance to the previously administered nucleoside analogue. A more preserved lymph node architecture and less signs of immunopathological change were also observed in protease inhibitor-treated patients. CONCLUSIONS Undetectable plasma viraemia using the ultrasensitive PCR assay for prolonged periods of time does not always reflect complete HIV-1 suppression within the lymphoid compartment. Our results suggest that protease inhibitor-containing regimens target HIV reservoirs in lymphoid tissue more effectively and preserve or restore lymph node architecture.

Lactobacillus fermentum CECT 5716 prevents and reverts intestinal damage on TNBS-induced colitis in mice.

Background: Probiotics attenuate gut inflammation when administered before experimental colitis, but data on their effect after colitis induction are scarce. We aimed to evaluate the effects of Lactobacillus fermentum CECT 5716 on gut injury when administered either before or after trinitrobencene sulfonic acid (TNBS) colitis in Balb/c mice. Methods: In a preventive study, probiotic or vehicle was administered for 2 weeks before colitis. Then mice were allocated to: probiotic + TNBS, probiotic + sham, vehicle + TNBS, or vehicle + sham, and sacrificed 72 hours later. In a therapeutic study, mice were allocated into the same groups as before. Probiotic or vehicle were administered for 3 weeks. Mice were sacrificed at weeks 1, 2, and 3 after TNBS. Histological score, myeloperoxidase activity, and eicosanoid and cytokine production in colonic explant cultures were measured. Immunohistochemistry for nitrotyrosine and MyD88 was also performed. Results: In the preventive study, colitis was milder with probiotic than with vehicle (P = 0.041). This was associated with increased PGE2, IL‐2, and IL‐4 production, as well as attenuated nitrotyrosine staining in the former. In the therapeutic study, histological score at week 1 post‐TNBS was higher in probiotic than in vehicle fed mice (P = 0.018). However, at weeks 2 and 3 the histological score was significantly lower—with decreased IL‐6 production and increased MyD88 staining—in mice receiving the probiotic. Conclusions: Pretreatment with L. fermentum CECT 5716 attenuates TNBS colitis, an effect that seems to be due to its antioxidant abilities. When administered after TNBS, this probiotic is also effective in accelerating colitis recovery, and this is associated with an enhanced Toll‐like receptor function. (Inflamm Bowel Dis 2009)

Insulin-like growth factor-I improves intestinal barrier function in cirrhotic rats

Background and aims: In liver cirrhosis, disruption of the intestinal barrier facilitates bacterial translocation and spontaneous bacterial peritonitis. Insulin-like growth factor I (IGF-I) is an anabolic hormone synthesised by hepatocytes that displays hepatoprotective activities and trophic effects on the intestine. The aim of this study was to investigate the effect of IGF-I on intestinal barrier function in cirrhotic rats. Methods: In rats with carbon tetrachloride induced cirrhosis, we investigated the effect of IGF-I therapy on: (a) portal pressure; (b) intestinal histology and permeability to endotoxin and bacteria; (c) intestinal expression of cyclooxygenase 2 (COX-2) and tumour necrosis factor α (TNF-α), two factors that influence in a positive and negative manner, respectively, the integrity of the intestinal barrier; (d) intestinal permeability to 3H-mannitol in rats with bile duct ligation (BDL); and (e) transepithelial electrical resistance (TER) of polarised monolayers of rat small intestine epithelial cells. Results: IGF-I therapy reduced liver collagen expression and portal pressure in cirrhotic rats, induced improvement in intestinal histology, and caused a reduction in bacterial translocation and endotoxaemia. These changes were associated with diminished TNF-α expression and elevated COX-2 levels in the intestine. IGF-I reduced intestinal permeability in BDL rats and enhanced barrier function of the monolayers of epithelial intestinal cells where lipopolysaccharide (LPS) caused a decrease in TER that was reversed by IGF-I. This effect of IGF-I was associated with upregulation of COX-2 in LPS treated enterocytes. Conclusions: IGF-I enhances intestinal barrier function and reduces endotoxaemia and bacterial translocation in cirrhotic rats. IGF-I therapy might be useful in the prevention of spontaneous bacterial peritonitis in liver cirrhosis.

Accuracy of Simple Biochemical Tests in Identifying Liver Fibrosis in Patients Co-Infected With Human Immunodeficiency Virus and Hepatitis C Virus

BACKGROUND & AIMS We assessed the ability of 3 simple biochemical tests to stage liver fibrosis in patients co-infected with human immunodeficiency virus (HIV) and hepatitis C virus (HCV). METHODS We analyzed liver biopsy samples from 324 consecutive HIV/HCV-positive patients (72% men; mean age, 38 y; mean CD4+ T-cell counts, 548 cells/mm(3)). Scheuer fibrosis scores were as follows: 30% had F0, 22% had F1, 19% had F2, 23% had F3, and 6% had F4. Logistic regression analyses were used to predict the probability of significant (>or=F2) or advanced (>or=F3) fibrosis, based on numeric scores from the APRI, FORNS, or FIB-4 tests (alone and in combination). Area under the receiver operating characteristic curves were analyzed to assess diagnostic performance. RESULTS Area under the receiver operating characteristic curves analyses indicated that the 3 tests had similar abilities to identify F2 and F3; the ability of APRI, FORNS, and FIB-4 were as follows: F2 or greater: 0.72, 0.67, and 0.72, respectively; F3 or greater: 0.75, 0.73, and 0.78, respectively. The accuracy of each test in predicting which samples were F3 or greater was significantly higher than for F2 or greater (APRI, FORNS, and FIB-4: >or=F3: 75%, 76%, and 76%, respectively; >or=F2: 66%, 62%, and 68%, respectively). By using the lowest cut-off values for all 3 tests, F3 or greater was ruled out with sensitivity and negative predictive values of 79% to 94% and 87% to 91%, respectively, and 47% to 70% accuracy. Advanced liver fibrosis (>or=F3) was identified using the highest cut-off value, with specificity and positive predictive values of 90% to 96% and 63% to 73%, respectively, and 75% to 77% accuracy. CONCLUSIONS Simple biochemical tests accurately predicted liver fibrosis in more than half the HIV/HCV co-infected patients. The absence and presence of liver fibrosis are predicted fairly using the lowest and highest cut-off levels, respectively.

Proliferating cell nuclear antigen expression in normal, regenerative, and neoplastic liver: A fine-needle aspiration cytology and biopsy study

Information about a tissues proliferative activity can be obtained from the immunocytochemical investigation of proliferating cell nuclear antigen (PCNA), an auxiliary protein of DNA polymerase delta expressed by cycling cells. To determine whether a relationship exists between morphology and PCNA expression in normal, regenerative, and malignant neoplastic hepatocytes, this study was undertaken on 48 fine-needle aspiration cytology (FNAC) cell blocks from eight normal livers, eight cirrhotic livers, and 32 hepatocellular carcinomas (HCCs), as well as on 41 needle or wedge biopsy specimens from 10 normal livers, 13 cirrhotic livers, one focal nodular hyperplastic liver, and 17 HCCs. Anti-PCNA monoclonal antibody PC10 was applied to formalin-fixed, paraffin-embedded tissue using the avidin-biotin method. Proliferating cell nuclear antigen immunoreactivity was evaluated as follows: absent; minimal, less than 5% positive nuclei; grade 1, 5% to 25% positive nuclei; grade 2, 26% to 50% positive nuclei; grade 3, 51% to 75% positive nuclei; and grade 4, 76% to 100% positive nuclei. In both the FNAC and biopsy series normal and regenerative livers were either completely negative or minimally immunoreactive (under 5% positive nuclei). In contrast, all well-differentiated HCC cases exhibited over 15% positive nuclei. Most well-differentiated HCCs were grade 1 (85.7% in the FNAC series and 76.92% in the biopsy series) and the majority of moderately differentiated HCCs were grade 3 (63.63% in the FNAC series, but only 50% in the biopsy series). Therefore, absent or minimal PCNA immunoreactivity seems to be a useful adjuvant to discriminate normal/regenerative liver from HCC, whose degree of differentiation tends to correlate with the level of PCNA expression. These observations apply to both the FNAC and biopsy series, which yielded very similar data.