IgG deposits can be detected in cell nuclei of patients with both lupus erythematosus and malignancy

The purpose was to find immunological disturbances in lupus erythematosus (LE) patients with concomitant malignancy. 159 LE patients have been analyzed. Routine laboratory analyses including screening of serum autoantibodies and analyzing peripheral blood mononuclear cells by using flow cytometry have been performed. Malignant diseases have been revealed in 12 (7.5%) cases. All patients suffered from internal malignancies. LE patients with vs without malignancy had significantly decreased anti-double stranded DNA (16.6 vs 31.6%; p < 0.05) and increased anti-SSA/SSB (83.3 vs 32.2%/26.4%; p < 3 × 10⁻¹²) antibodies. Patients with neoplastic disease had increased IgG within the cell nuclei (76.6% ± 9.6 vs 51.8 ± 4.6%; p < 2 × 10⁻⁷). IgG penetrating living cells has been shown previously in SLE but has so far not been found in association to LE patients with malignant disease.