Serum Mannose-Binding Lectin Levels are Linked with Respiratory Syncytial Virus (RSV) Disease

Abstract

The innate immune response facilitates the quality of the adaptive immune response and is critical to an individual's susceptibility to infection and disease. Mannose-binding lectin (MBL) is a plasma protein with anti-microbial properties that binds a wide range of pathogens to flag them for immune destruction independent of antibodies. In this study, serum MBL levels were measured in 81 children <5 years old experiencing acute respiratory syncytial virus infection and in 40 control children to determine the association with disease severity. Almost 70% of all RSV-infected children had low to intermediate MBL levels (<500 ng/ml) compared to controls, and most of the <6 months old RSV interned patients had low to intermediate levels. No differences were detected in MBL levels between case and control children <1 month old. Analysis of the T-cell compartment in peripheral blood mononuclear cells (PBMC) from acute RSV-infected and control children showed that the percent CD4+ T cells was statistically lower in RSV-infected children > or =6 months old compared to controls, while the percent CD8+ T cells in RSV-infected and control PBMC was generally similar. These results suggest that low serum MBL levels may be a marker of RSV disease severity in children and that MBL may be important in limiting RSV disease pathogenesis.

Torque Teno Virus Viremia Load Size in Patients with Selected Congenital Defects of Innate Immunity

“…In conclusion, consistent with findings from other viral infections (4,6,8,10,12,(24)(25)(26), MBL2 polymorphisms known to lead to MBL deficiencies were associated with higher TTV VLs than was wild-type MBL2, supporting the view that innate immunity efficiency contributes to determining the TTV VL size. The increase was modest but might have been greater had we examined subjects earlier in infancy, when the role of MBL in antimicrobial resistance is most important (5,28).…”

“…MBL, encoded by gene MBL2 on chromosome 10, is a pattern recognition protein that exerts its protective action by activating the complement cascade through an antibody-independent pathway triggered by its binding to pathogen surfaces and other mechanisms (13). MBL is probably most important in antibacterial defenses (14) but also plays a significant role against viruses; indeed, MBL2 polymorphisms known to lead to lower-than-normal blood concentrations of functional MBL have been linked with an increased susceptibility to several enveloped and nonenveloped viruses (3,4,6,8,10,12,24,25,26). Furthermore, because the airways are colonized by TTV early in life and may represent a port of body entry (18), we conducted the investigation with patients being evaluated to confirm or exclude the presence of primary ciliary dyskinesia (PCD).…”

Mannose-binding lectin deficiency in respiratory diseases

“…Согласно экспериментальным данным, доказываю щим распознающую функцию MBL в отношении вирусов [6], а также отдельным наблюдениям пока зано, что дефицит MBL предрасполагает к более тяжелому течению респираторно синцитиальной инфекции у детей [13], тяжелому острому респи раторному синдрому в китайской популяции [14] и осложненному течению вакцинации против грип па [15]. Иранскими учеными недавно показана связь дефицита MBL с рецидивирующими инфекциями респираторного тракта [16].…”

Ausência de escapes mutantes para o medicamento palivizumab® do Vírus Respiratório Sincicial Humano (hRSV) circulante, na cidade de São Paulo durante o ano de 2004.

“…Em geral a resposta imune, envolvendo anticorpos secretores e anticorpos no soro, parece proteger contra infecção no trato respiratório superior e inferior, enquanto a resposta imune, mediada por células, é direcionada contra proteínas internas, sendo este fator determinante para infecção (Hurk, 2007). Ribeiro et al, (2008), num estudo feito em Uberlândia, relatou que pacientes maiores de 6 meses de vida também tinham níveis baixos MBL (Serum Mannose-…”

“…Campinas (Silva et al, 2008), Uberlândia (Serafino et al, 2004(Serafino et al, ,2008 e Aracajú (Ribeiro et al, 2008), os autores também descreveram uma sazonalidade típica, com surtos ocorrendo entre os meses de março a setembro e com picos de incidência nos meses de abril, maio e junho (Bosso et al, 2004;Campos et al, 2007;doNascimento et al, 2008). O hRSV é dividido em dois grupos A e B, sendo que a maior diferença está na glicoproteína G (Mufson et al, 1985;Johnson et al, 1987;Hendry et al, 1988).…”