Felipe Rodríguez de Castro

Severe alpha1 antitrypsin deficiency has been clearly associated with pulmonary emphysema, but its relationship with bronchial asthma remains controversial. Some deficient alpha 1 antitrypsin (AAT) genotypes seem to be associated with asthma development. The objective of this study was to analyze the distribution of AAT genotypes in asthmatic patients allergic to house dust mites (HDM), and to asses a possible association between these genotypes and severe asthma. A cross-sectional cohort study of 648 patients with HDM allergic asthma was carried out. Demographic, clinical and analytical variables were collected. PI*S and PI*Z AAT deficient alleles of the SERPINA1 gene were assayed by real-time PCR. Asthma was intermittent in 253 patients and persistent in 395 patients (246 mild, 101 moderate and 48 severe). One hundred and forty-five asthmatic patients (22.4%) with at least one mutated allele (S or Z) were identified. No association between the different genotypes and asthma severity was found. No significant differences in all clinical and functional tests, as well as nasal eosinophils, IgA and IgE serum levels were observed. Peripheral eosinophils were significantly lower in patients with the PI*MS genotype (p = 0.0228). Neither association between deficient AAT genotypes or serum ATT deficiency (AATD) and development of severe asthma, or correlation between ATT levels and FEV1 was observed. In conclusion, the distribution of AAT genotypes in HDM allergic asthmatic patients did not differ from those found in Spanish population. Neither severe ATTD or deficient AAT genotypes appear to confer different clinical expression of asthma.

Influenza virus infection (IVI) is typically subclinical or causes a self-limiting upper respiratory disease. However, in a small subset of patients IVI rapidly progresses to primary viral pneumonia (PVP) with respiratory failure; a minority of patients require intensive care unit admission. Inherited and acquired variability in host immune responses may influence susceptibility and outcome of IVI. However, the molecular basis of such human factors remains largely elusive. It has been proposed that homozygosity for IFITM3 rs12252-C is associated with a population-attributable risk of 5.4 % for severe IVI in Northern Europeans and 54.3 % for severe H1N1pdm infection in Chinese. A total of 148 patients with confirmed IVI were considered for recruitment; 118 Spanish patients (60 of them hospitalized with PVP) and 246 healthy Spanish individuals were finally included in the statistical analysis. PCR-RFLP was used with confirmation by Sanger sequencing. The allele frequency for rs12252-C was found to be 3.5 % among the general Spanish population. We found no rs12252-C homozygous individuals in our control group. The only Spanish patient homozygous for rs12252-C had a neurological disorder (a known risk factor for severe IVI) and mild influenza. Our data do not suggest a role of rs12252-C in the development of severe IVI in our population. These data may be relevant to recognize whether patients homozygous for rs12252-C are at risk of severe influenza, and hence require individualized measures in the case of IVI.

Severe sepsis, may be present on hospital arrival in approximately one-third of patients with community-acquired pneumonia (CAP). To determine the host characteristics and micro-organisms associated with severe sepsis in patients hospitalized with CAP. We performed a prospective multicenter cohort study in 13 Spanish hospital, on 4070 hospitalized CAP patients, 1529 of whom (37.6%) presented with severe sepsis. Severe sepsis CAP was independently associated with older age (>65 years), alcohol abuse (OR, 1.31; 95% CI, 1.07–1.61), chronic obstructive pulmonary disease (COPD) (OR, 1.75; 95% CI, 1.50–2.04) and renal disease (OR, 1.57; 95% CI, 1.21–2.03), whereas prior antibiotic treatment was a protective factor (OR, 0.62; 95% CI, 0.52–0.73). Bacteremia (OR, 1.37; 95% CI, 1.05–1.79), S pneumoniae (OR, 1.59; 95% CI, 1.31–1.95) and mixed microbial etiology (OR, 1.65; 95% CI, 1.10–2.49) were associated with severe sepsis CAP. CAP patients with COPD, renal disease and alcohol abuse, as well as those with CAP due to S pneumonia or mixed micro-organisms are more likely to present to the hospital with severe sepsis.

Introduction: Inherited variability in host immune responses influences susceptibility and outcome of Influenza A virus (IAV) infection, but these factors remain largely unknown. Components of the innate immune response may be crucial in the first days of the infection. The collectins surfactant protein (SP)-A1, -A2, and -D and mannose-binding lectin (MBL) neutralize IAV infectivity, although only SP-A2 can establish an efficient neutralization of poorly glycosylated pandemic IAV strains. Methods: We studied the role of polymorphic variants at the genes of MBL (MBL2), SP-A1 (SFTPA1), SP-A2 (SFTPA2), and SP-D (SFTPD) in 93 patients with H1N1 pandemic 2009 (H1N1pdm) infection. Results: Multivariate analysis showed that two frequent SFTPA2 missense alleles (rs1965708-C and rs1059046-A) and the SFTPA2 haplotype 1A ⁰ were associated with a need for mechanical ventilation, acute respiratory failure, and acute respiratory distress syndrome. The SFTPA2 haplotype 1A ¹ was a protective variant. Kaplan-Meier analysis and Cox regression also showed that diplotypes not containing the 1A ¹ haplotype were associated with a significantly shorter time to ICU admission in hospitalized patients. In addition, rs1965708-C (P = 0.0007), rs1059046-A (P = 0.0007), and haplotype 1A ⁰ (P = 0.0004) were associated, in a dose-dependent fashion, with lower PaO₂/FiO₂ ratio, whereas haplotype 1A ¹ was associated with a higher PaO₂/FiO₂ ratio (P = 0.001). Conclusions: Our data suggest an effect of genetic variants of SFTPA2 on the severity of H1N1pdm infection and could pave the way for a potential treatment with haplotype-specific (1A ¹ ) SP-A2 for future IAV pandemics.

Introduction: Genetic variability of the pulmonary surfactant proteins A and D may affect clearance of microorganisms and the extent of the inflammatory response. The genes of these collectins (SFTPA1, SFTPA2 and SFTPD) are located in a cluster at 10q21-24. The objective of this study was to evaluate the existence of linkage disequilibrium (LD) among these genes, and the association of variability at these genes with susceptibility and outcome of community-acquired pneumonia (CAP). We also studied the effect of genetic variability on SP-D serum levels. Methods: Seven non-synonymous polymorphisms of SFTPA1, SFTPA2 and SFTPD were analyzed. For susceptibility, 682 CAP patients and 769 controls were studied in a case-control study. Severity and outcome were evaluated in a prospective study. Haplotypes were inferred and LD was characterized. SP-D serum levels were measured in healthy controls. Results: The SFTPD aa11-C allele was significantly associated with lower SP-D serum levels, in a dose-dependent manner. We observed the existence of LD among the studied genes. Haplotypes SFTPA1 6A ² (P = 0.0009, odds ration (OR) = 0.78), SFTPA2 1A ⁰ (P = 0.002, OR = 0.79), SFTPA1-SFTPA2 6A ² -1A ⁰ (P = 0.0005, OR = 0.77), and SFTPD-SFTPA1-SFTPA2 C-6A ² -1A ⁰ (P = 0.00001, OR = 0.62) were underrepresented in patients, whereas haplotypes SFTPA2 1A ¹⁰ (P = 0.00007, OR = 6.58) and SFTPA1-SFTPA2 6A ³ -1A (P = 0.0007, OR = 3.92) were overrepresented. Similar results were observed in CAP due to pneumococcus, though no significant differences were now observed after Bonferroni corrections. 1A ¹⁰ and 6A-1A were associated with higher 28-day and 90-day mortality, and with multi-organ dysfunction syndrome (MODS) and acute respiratory distress syndrome (ARDS) respectively. SFTPD aa11-C allele was associated with development of MODS and ARDS. Conclusions: Our study indicates that missense single nucleotide polymorphisms and haplotypes of SFTPA1, SFTPA2 and SFTPD are associated with susceptibility to CAP, and that several haplotypes also influence severity and outcome of CAP.

Drug options for treatment of infections are increasingly limited. The pharmaceutical industry has found it difficult to discover new antimicrobial agents, and only two novel classes of antibiotics, the oxazolidinones and the cyclic lipopeptides, have entered the market since the late 1960s. Few new agents have reached the market in the last decade with potential interest for community-acquired pneumonia (CAP) treatment, including linezolid (the first oxazolidinone in clinical use), new fluoroquinolones, cefditoren, ertapenem, and telithromycin. Agents currently in clinical development include other novel quinolones and ketolides, broad-spectrum cephalosporin derivatives, faropenem, several glycopeptides, and iclaprim. Other molecules are considered to be promising candidates for the future. In addition to the foregoing agents, alternative treatment approaches have also been introduced into clinical practice, which include the administration of the appropriate antimicrobials in a timely manner and the consideration of the pharmacokinetic–pharmacodynamic properties of the agent(s).