Increased immunoglobulin A (IgA) levels were detected in nine individuals, from three unrelated families, who had hereditary sensory neuropathy. Other immunoglobulin levels were generally normal, and serum IgA was not elevated in unaffected family members. No accompanying disorder was detected that could have accounted for the dysgammaglobulinemia. No noteworthy immunologic abnormality besides that of IgA was present. In a series of metabolic and immunologic studies, it was shown that the increased amounts of IgA resulted from increased synthesis and the jejunal mucosa was a major site of the excessive production. The jejunal wall also contained increased numbers of eosinophils.
Although the gastrointestinal abnormality is associated with the neuropathy, it could be causally unrelated; however, our study raises the alternative possibility that an occult gastrointestinal infection might play a role in the pathogenesis of the neuropathy.
Whitaker JN, Falchuck ZM, Engel WK, Blaese RM, Strober W. Hereditary Sensory NeuropathyAssociation With Increased Synthesis of Immunoglobulin A. Arch Neurol. 1974;30(5):359-371. doi:10.1001/archneur.1974.00490350017003