ANA-Negative Presentation of SLE in Man with Severe Autoimmune Neutropenia

Abstract

Background. Systemic lupus erythematosus (SLE) is a chronic, inflammatory, connective tissue disease that commonly affects the joints and a variety of organs due to an overactivation of the body's immune system. There is wide heterogeneity in presentation of SLE patients, including lung, central nervous system, skin, kidney, and hematologic manifestations. Case Presentation. We report a case of atypical manifestation of SLE in a 53-year-old man who presented with neutropenic fever. Physical findings of interest included oral ulcers on the lower lip, a malar-like rash across the bridge of the nose, and a discoid-like rash on extensor surfaces of the elbows and knees. Labs include ANC <100, weakly positive anti-dsDNA, negative ANA, ferritin 1237 ng/mL, low C3/C4, and positive direct Coombs' test. A thorough workup for infection and hematologic malignancy was negative. Two days after initiation of therapy with 25 mg IV solumedrol twice a day, the patient's daily fevers resolved. ANC drastically improved to 2000 after two weeks of steroid treatment. He was later found to have a high titer of anti-neutrophil antibodies. Discussion. Autoimmune leukopenia is a common presentation in SLE, occurring in 50-60% of patients. Severe autoimmune neutropenia is uncommon and may correlate with high anti-neutrophil antibody activity despite a negative ANA. As neutropenia is usually mild, there are currently no guidelines for therapy. For our patient, we started him on low dose IV solumedrol and found that he responded drastically to treatment. Given strongly positive nonspecific anti-neutrophil antibodies in the setting of a negative ANA noted in our patient, it is likely that there are other currently unknown antibodies associated with SLE which may correlate strongly with autoimmune neutropenia.