The emerging literature in several areas points to complex interactions between exposure to microbial pathogens and susceptibility to the induction and expression of allergic diseases exemplified by atopic asthma. Earlier notions that infections protect against allergy by enhancing Th1-associated immunity have been supplanted by a broader understanding of the relevance of issues, such as timing, type and intensity of infections, to the underlying disease process. Many issues BIBW2992 remain to be resolved, and this will remain a ‘hot topic’ in the allergy field for some time

to come. The authors have no conflicts of interest to declare. “
“Immunoglobulin (Ig) replacement therapy has substantially changed the life of patients with primary antibody deficiency (PAD). In the majority of cases, patients with common variable immunodeficiency (CVID) or X-linked agammaglobulinaemia (XLA) now live to lead a near-normal life. Modern Selleckchem DAPT production facilities, a series of safety measures and a choice of several ways of

administration make Ig replacement a safe and relatively easy therapy to use. The well-known presentations of PAD, such as pneumonia, septicaemia and other invasive bacterial infections [1], would continue to occur in PAD patients without regular replacement therapy. In this paper, we comment on the success and limitations of our present Ig replacement therapy in PAD. We also speculate how further improvement can be achieved in the treatment of complications from which PAD patients continue to suffer. IgG replacement effectively prevents pneumonia and invasive bacterial infections, as shown in several large cohorts.

For instance, in a large Italian cohort of CVID patients, the prevalence of pneumonia was reduced from 49·0 to 20·5% upon initiation of Ig therapy [2]. Prevention of pneumonia by Ig replacement therapy appears to be possible in a dose-dependent fashion. In a meta-analysis on IgG trough levels of 676 patients, the risk of pneumonia declined by 27% with each 0·1 g/kg body weight increment in the monthly IgG dose [3], although other factors, such as individual IgA levels, may determine the risk of pneumonia even more Plasmin strongly [4]. However, the effect of IgG replacement therapy on bacterial bronchitis and sinusitis in PAD patients is less clear. In the Italian CVID cohort, prevalence of chronic bacterial airway infections rose markedly from time at diagnosis through an observation period of a mean of 11 years of performed IgG replacement therapy. Frequency of both chronic bronchitis and sinusitis increased from 33·9 to 46·4% and from 36·6 to 54·0%, respectively [2]. The increase of these conditions during Ig therapy was described similarly in XLA patients [1, 4]. Chronic bronchitis and sinusitis in PAD is due almost exclusively to chronic bacterial infection.