Marco A. Montes-Cano

Interleukin-28B genetic variants and hepatitis virus infection by different viral genotypes.

Genetic host factors may modify the course of the hepatitis C virus (HCV) infection. Very recently, a genome‐wide scan that reported association of the IL28B locus with response to treatment in HCV infection was published. The aim of the current study was to investigate the relationship of this locus with outcome of HCV infection in a cohort constituted by a total of 731 Spanish individuals. From these, 284 were subjects with persistent infection, 69 were individuals who naturally cleared the virus, and 378 were noninfected subjects. Genotyping of the rs12979860 (C>T) in the IL28B locus was performed using a TaqMan 5′ allelic discrimination assay. The CC genotype was overrepresented among patients infected with viral genotypes non‐1 (66.7% versus 39.1% in patients infected with viral genotype‐1, P = 8.5 × 10−5, odds ratio [OR] = 0.32, 95% confidence interval [CI] 0.17‐0.60); patients with spontaneous resolution of infection (72.5% versus 45.6% of the individuals with persistent infection, P = 6.2 × 10−5, OR = 0.32; 95%CI, 0.18‐0.57); and lastly, patients with sustained response (60.2% versus 32.1% found in patients with nonsustained response, P = 3.1 × 10−5, OR = 0.31; 95%CI, 0.17‐0.56). Conclusion: We have found different rates of viral genotype infection depending on the IL28B variant as well as an association of this locus with natural and treatment‐mediated response. HEPATOLOGY 2010

Pneumocystis jirovecii in General Population

P. jirovecii colonization can be frequently detected in immunocompetent adults, which suggests that the general population could be a source of this infection.

Systemic Inflammation in Patients with Chronic Obstructive Pulmonary Disease Who Are Colonized with Pneumocystis jiroveci

In chronic obstructive pulmonary disease, high levels of airway and systemic inflammatory markers are associated with a faster decrease in lung function. Our study shows that patients colonized by Pneumocystis jiroveci have higher proinflammatory cytokine levels than do noncolonized patients. This suggests that Pneumocystis may play a role in disease progression.

Pneumocystis jirovecii transmission from immunocompetent carriers to infant.

We report a case of Pneumocystis jirovecii transmission from colonized grandparents to their infant granddaughter. Genotyping of P. jirovecii showed the same genotypes in samples from the infant and her grandparents. These findings support P. jirovecii transmission from immunocompetent carrier adults to a susceptible child.

Pneumocystis jirovecii colonization in patients treated with infliximab

Eur J Clin Invest 2011; 41 (3): 343–348

HLA class I B44 is associated with sustained response to interferon + ribavirin therapy in patients with chronic hepatitis C

OBJECTIVE:The aim of this study was to assess the influence of host genetic factors on response to combination therapy for chronic hepatitis C infection.METHODS:Patients with biopsy-proved chronic hepatitis C infection were treated with interferon alone (n = 143) or combined therapy of interferon + ribavarin (n = 105; 46 treatment naïve, 59 relapsers). Human leukocyte antigen (HLA) class I was determined by microlymphocytotoxicity and class II by polymerase chain reaction-single specific oligonucleotide. The two biallelic tumor necrosis factor-α promoter polymorphisms were studied by a polymerase chain reaction-amplification refractory mutation system. Other variables measured were viral genotype, hepatitis C virus RNA load, liver function tests, and ferritin concentration.RESULTS:Univariate analysis indicated that patients bearing HLA B44+, DRB1*03, infected by genotype non-1, with higher concentrations of transaminases and shorter duration of infection showed a higher sustained response (SR) rate than those on combination therapy. HLA class II and TNF-α promoter polymorphisms were not related to SR. In multivariate analysis, non-1 genotype (OR 2.42, 95% CI 1.12–5.55, p = 0.026) and HLA B44+ (OR 4.84, 95% CI 1.3–17.8, p = 0.017) were the independent variables associated with SR. However, HLA B44+ was not associated with SR in patients treated with interferon alone.CONCLUSIONS:HLA class I B44 is related to a higher rate of SR in combination therapy but not in interferon monotherapy, whereas HLA class II, tumor necrosis factor-α −238A or −308A seem not to influence response to the antiviral therapy. These findings may be of value in therapy selection for hepatitis C-infected patients.

Fecal gluten peptides reveal limitations of serological tests and food questionnaires for monitoring gluten-free diet in celiac disease patients

Objectives:Treatment for celiac disease (CD) is a lifelong strict gluten-free diet (GFD). Patients should be followed-up with dietary interviews and serology as CD markers to ensure adherence to the diet. However, none of these methods offer an accurate measure of dietary compliance. Our aim was to evaluate the measurement of gluten immunogenic peptides (GIP) in stools as a marker of GFD adherence in CD patients and compare it with traditional methods of GFD monitoring.Methods:We performed a prospective, nonrandomized, multicenter study including 188 CD patients on GFD and 84 healthy controls. Subjects were given a dietary questionnaire and fecal GIP quantified by enzyme-linked immunosorbent assay (ELISA). Serological anti-tissue transglutaminase (anti-tTG) IgA and anti-deamidated gliadin peptide (anti-DGP) IgA antibodies were measured simultaneously.Results:Of the 188 celiac patients, 56 (29.8%) had detectable GIP levels in stools. There was significant association between age and GIP in stools that revealed increasing dietary transgressions with advancing age (39.2% in subjects ≥13 years old) and with gender in certain age groups (60% in men ≥13 years old). No association was found between fecal GIP and dietary questionnaire or anti-tTG antibodies. However, association was detected between GIP and anti-DGP antibodies, although 46 of the 53 GIP stool-positive patients were negative for anti-DGP.Conclusions:Detection of gluten peptides in stools reveals limitations of traditional methods for monitoring GFD in celiac patients. The GIP ELISA enables direct and quantitative assessment of gluten exposure early after ingestion and could aid in the diagnosis and clinical management of nonresponsive CD and refractory CD. Trial registration number NCT02711397.

High prevalence of Pneumocystis jirovecii colonization in Brazilian cystic fibrosis patients.

A high rate of Pneumocystis jirovecii colonization was observed in Brazilian cystic fibrosis (CF) patients (13 out of 34; 38.2%) who underwent bronchoscopy between March 2006 and August 2009 at the Hospital de Clinicas de Porto Alegre, Brazil. Bronchoalveolar lavage samples were collected from these patients and studied by nested PCR amplification of the mitochondrial gene coding for the large subunit ribosomal RNA (mtLSUrDNA). The observed rate of colonization was higher than that reported in European populations. Genotypic characterization of the mtLSUrDNA locus revealed a predominance of the polymorphisms 85C/248C (genotype 1) and 85T/248C (genotype 3), with all samples possessing the wild-type genotype of dihydropteroate synthase. These findings suggest that cystic fibrosis patients could be an important reservoir and source of P. jirovecii infection. Further studies are required to elucidate the role of this common fungal colonization in the evolution of CF patients.

Usefulness of oropharyngeal washings for identifying Pneumocystis jirovecii carriers.

PNEUMOCYSTIS jirovecii is the causative agent of Pneumocystis pneumonia (PcP), one of the most frequent and severe opportunistic infections in immunocompromised patients (Stringer et al. 2002). The incidence of PcP has decreased among AIDS patients in developed countries due to chemoprophylaxis and highly active anti-retroviral therapy (HAART). However, PcP remains an important cause of morbidity and mortality worldwide (Morris et al. 2004). Today, the interest in P. jirovecii infection is not only confined to patients with AIDS. It also represents a common and serious opportunistic infection in other immunodeficient groups such as those with autoimmune diseases as well as solid organ transplant recipients and cancer patients undergoing immunosuppressive therapy (Calderón et al. 2004a). Recent studies also demonstrated the presence of asymptomatic P. jirovecii colonization in patients with chronic pulmonary diseases (Respaldiza et al. 2005; Vidal et al. 2006). Despite the advances made in understanding human Pneumocystis infection, many aspects about its epidemiology and natural history remain unclear. For decades, diagnosis of PcP has relied on microscopic visualization of organisms in specimens obtained from the lung either by bronchoalveolar lavage (BAL) or by sputum induction. Currently, the ‘‘gold standard’’ for diagnosis of PcP involves using traditional cytochemical stains of BAL fluid and bright-field light microscopy. Fluorescence microscopy using immunofluorescent monoclonal antibodies enables greater sensitivity and specificity and is useful for analyzing induced-sputum samples (Elvin et al. 1988). Polymerase chain reaction amplification of P. jirovecii DNA increases sensitivity of detecting the organism and is used on sputum and BAL specimens containing only small numbers of organisms (Durand-Joly et al. 2005; Leibovitz et al. 1995). However, non-invasive procedures are sometimes needed when bronchoscopy or even sputum induction are difficult to perform, contraindicated, or unpleasant to the patient. Recently, PCR of oral washings was found to be an attractive non-invasive alternative method for diagnosing P. jirovecii infection. Oropharyngeal washings (OW) are obtained by having the patient rinse the mouth and gargle the throat using sterile saline. (Wakefield et al. 1993) first reported detecting P. jirovecii DNA by PCR by analyzing oral wash samples obtained from PcP patients. Subsequently, other workers have shown that oral or oropharyngeal lavage specimens are useful for diagnosing PcP in patients with severe respiratory distress or tendency to bleed who are unable to undergo bronchoscopy (Helweg-Larsen et al. 1997; Martino et al. 1999). The aim of this study was to evaluate PCR methods for efficacy in detecting P. jirovecii by analyzing OW samples from individuals without PcP but might harbor the organism. MATERIAL AND METHODS

Lymphocyte Response in Subjects with Chronic Pulmonary Disease Colonized by Pneumocystis jirovecii

Pneumocystis jirovecii, known also by its interim trinomial name as Pneumocystis carinii f. sp. hominis [1], continues to be one of the most important causes of opportunistic infections in AIDS patients and in HIV-negative immunocompromised patients [2]. The incidence of P. jirovecii pneumonia (PcP) has decreased in AIDS patients in developed countries with the use of specific chemoprophylaxis and, above all, with highly active antiretroviral therapy. In spite of this, PcP is still an important cause of morbidity and mortality in the western world and is a problem that is being identified more and more in developing countries [3]. Nowadays, interest in P. jirovecii infection is not confined to AIDS patients alone; it also represents a common and serious opportunistic infection in HIV-negative immunocompromised patients due to different causes, such as organ transplant recipients [4], patients with autoimmune diseases who receive immunosuppressive therapy [5], or patients with neoplasias, especially in those with lymphoproliferative diseases [6]. On the other hand, pneumonia caused by this microorganism is not limited to immunosuppressed patients; but, it can affect subjects with no apparent immunosuppression, as it has been well documented in recent publications, describing a series of PcP patients without evidence of immunodeficiency [7,8,9]. Moreover immunocompetent subjects without PcP can be colonized by the pathogen. In this sense, Pneumocystis carriage was found in 10–40% of patients with chronic obstructive disease [10–11]. The major predisposing factor for the development of PcP is impaired cell mediatedor humoral immune response [12]. In patients with HIV infection or T cell defects, the CD4þ T lymphocytes have been shown to play a major role in the defense against this infection. In fact PcP often occurs in AIDS patients with a severe lymphopenia and less that 200 CD4þ T lymphocytes/ml [13]. However, it is not known what changes occur in the lymphocyte response in immunocompetent subjects colonized by this pathogen. The aim of this initial study was to provide information on the lymphocyte response in immunocompetent patients who are colonized by P. jirovecii.