Monitoring oligoclonal immunoglobulins in cerebral spinal fluid using microLC-ESI-Q-TOF mass spectrometry

Our group has previously shown that mass spectrometry can be used to detect and quantify monoclonal and polyclonal immunoglobulin light chains in serum and urine from patients with monoclonal gammopathies and polyclonal hypergammaglobinemia. Here we demonstrate the use of the methodology, also referred to as monoclonal immunoglobulin Rapid Accurate Mass Measurement\with (miRAMM), to detect oligoclonal immunoglobulins above the polyclonal background in cerebral spinal fluid (CSF) and serum. We compared the findings for 56 paired CSF and serum samples analyzed by IgG IEF and miRAMM. The two methods were in agreement with 54 samples having concordant results (22 positive and 34 negative) and 2 that were positive by IgG IEF but negative by miRAMM. In addition to identifying oligoclonal immunoglobulins, miRAMM can be used to quantify and isotype each specific monoclonal immunoglobulin in CSF. This methodology has the potential to transform the way the inflammatory response is monitored in the CNS compartment.