[Immunological studies on conjunctivitis follicularis].
Conjunctivitis follicularis is characterized by the appearance of cellular infiltrates consisting of lymphocytes, eosinophils and mast cells; this has led to the assumption of an allergic etiology in many cases. In a first attempt to prove this hypothesis three cases of conjunctivitis follicularis were investigated using the following immunological methods: (1) determination of immunoglobulins in the lacrimal fluid by means of quantitative precipitation (IgG, IgA, IgM), and by a direct radioimmunoassay for IgE; (2) direct immunofluorescence test on cryostat sections of biopsy specimens of diseased conjunctiva to detect immunoglobulin-producing plasma cells. According to initial results the infiltrated conjunctiva contains considerable numbers of plasma cells producing mainly IgA, and IgM. Plasma cells positively stained with anti-IgG and notably with anti-IgE were only rarely found. These findings, which were also supported by the quantitative Ig determinations in the lacrimal fluids, tend to rule out an allergic, IgE-mediated pathomechanism in these cases.