Soluble CD26 and CD30 levels in patients with common variable immunodeficiency.

BACKGROUND Common variable immunodeficiency (CVID) is a heterogeneous group of disorders characterized by decreased serum immunoglobulin levels and increased susceptibility to recurrent bacterial infections. There is increasing evidence that the type 1 helper T cell (T(H)1)/T(H)2 cell balance is shifted towards a T(H) 1-type immune response in patients with CVID. This study was performed to measure levels of soluble CD26 (sCD26) and CD30 (sCD30) as plausible markers of a dysregulated immune response in a group of patients with CVID. METHODS Twenty-five patients with CVID and 20 age- and sex-matched controls were enrolled in this study. A sandwich enzyme-linked immunosorbent assay was used to measure serum sCD26 and sCD30 levels. RESULTS The mean (SD) serum sCD26 level was significantly higher in patients with CVID than in controls (88.47 [59.82] ng/mL vs 28.31 [25.61] ng/mL, P = .001). Serum sCD30 levels were also significantly higher in patients with CVID than in controls (196.37 [169.71] ng/mL vs 30.72 [12.98] ng/mL, P < .001). Analysis of serum sCD30 levels in association with different clinical variables indicated that patients with splenomegaly and malignancy had significantly higher levels than patients without these disorders. However, serum sCD30 levels did not differ with bronchiectasis or autoimmunity. CONCLUSIONS The presence of increased serum levels of sCD26 and sCD30 in patients with CVID suggests that CVID patients have a polarized immune response towards a T(H)1-like phenotype, whereas the association between high levels of these markers and disease severity suggests that the soluble form could be used as a prognostic tool in CVID.