To present a unique case where detection of oligoclonal bands in serum led to the diagnosis of human immunodeficiency virus (HIV) infection.
A 64-year-old man treated for hypertension for 11 years had laboratory tests ordered by his primary care physician, including serum protein electrophoresis (SPE) and serum immunofixation electrophoresis.
The total protein serum protein concentration was elevated at 9.6 g/dL. The SPE showed an oligoclonal pattern of multiple discrete bands in the γ region; the concentration of one band was approximately 1 g/dL and that of two bands was approximately 0.5 g/dL each, with multiple smaller overlapping bands at approximately 0.1 g/dL each. All fractions by SPE were within reference intervals except for the γ fraction, which was elevated at 3.4 g/dL. The IFE demonstrated that this oligoclonal pattern was a mixture of multiple bands of immunoglobulin G (IgG)-λ and IgG-κ. The patient's HIV-1 antibody screen and HIV-1 Western blot were positive on three subsequent visits with strongly positive HIV-1 antibody index values of more than 50 (cutoff value of 1.0 for reactivity).
The etiology of HIV-associated clonal immunoglobulin bands is hypothesized to result from chronic antigenic stimulation leading to B-cell hyperplasia. In this regard, hypergammaglobulinemia is a well-known consequence of HIV infection due to B-cell activation, associated with paraproteins, and can be seen at any stage of the disease.