Determination of ligand binding capacity of soluble FcγRII and FcγRIII in sera of patients with SLE

Background: Soluble, human low affinity Fcγ receptors, such as sFcγRII and sFcγRIII, are known to play a pathologic role in different diseases. Sandwich ELISAs had previously been applied for the specific detection and determination of these soluble receptors. In these ELISAs, commercial monoclonal antibodies (Ab) were used as capture antibodies with monoclonal or polyclonal antibodies serving as detector Abs. Increased levels of cell-free FcγRIII have been detected in patients with lupus but the functions and levels of sFcγRII have not been fully characterized yet.Objectives: The aim of this work was to determine the ligand binding capacities and levels of soluble FcγRII and FcγRIII in sera of patients with systemic lupus erythematosus (SLE). Moreover, correlation between the levels of sFcγRII and sFcγRIII and the clinical activity of the disease were investigated.Methods: Sera of 47 patients with SLE, and 51 healthy subjects were analyzed. In the newly developed indirect sandwich ELISAs commercial monoc...