Various other end-points evaluating the efficacy of IgG therapy in patients with PI have been explored. Pulmonary click here function has been studied [15–20],

but the lack of sensitivity of the available methods has prevented the wide use of this measure. The Chest CT in ADS Group (http://www.chest-ct-group.eu/), an international group of immunologists, pulmonologists and radiologists, has developed a methodology for improving the diagnosis of disease in patients with antibody deficiency syndrome. This group uses high-resolution chest computed tomography (CT) scanning along with a battery of lung function tests which are used to give a CT score to track the progression of lung disease. The potential

use of C-reactive protein (CRP) as an indicator of IgG therapy efficacy was discussed. CRP is an acute-phase protein produced in response to various stimuli involving tissue damage such as inflammation and infection. Serum CRP has been used extensively as a marker of bacterial infection [21]. However, due to its low specificity, its true diagnostic value in clinical practice has been questioned [22,23]. A retrospective, single-centre study was carried out to examine the association between CRP levels and clinical outcomes in patients with CVID on immunoglobulin replacement. The cohort consisted of 112 CVID patients Olaparib supplier and was divided into three groups based on median CRP values (0–5, 5–10 and > 10 mg/l). There were 10 patients in the > 10 mg/l group. There were a large number of patients in both 0–5 and 5–10 mg/l groups and 12 patients were selected randomly from each group for the analysis. Five outcome parameters

were investigated: number of infections, number of serious Guanylate cyclase 2C infections, number of antibiotic courses, days off sick and days in hospital. These parameters are also part of the quality of life data set in the ESID database [14]. The working hypothesis was that these outcome parameters would correlate positively with serum CRP levels. However, when considering CRP on a continuous scale, no strong evidence of an association between CRP and any of the parameters examined was found (Table 1). Only weak evidence of an association between CRP and the number of serious infections was observed, but this was not statistically significant (P = 0·08). The Spearman’s rank correlation coefficient between the two variables was positive, suggesting that the number of serious infections increased with increasing serum CRP level. When the CRP measurements were divided into three categories (0–5, 5–10 and > 10 mg/l), the Kruskal–Wallis analysis suggested that there was not enough evidence that any of the outcome parameters varied between CRP categories (Table 1).