A Boy Presenting with a Fever and Pancytopenia Diagnosed with Systemic Lupus Erythematosus without a Positive Anti-ds-DNA Antibody Result or Hypocomplementemia: A Case Report.

Background: Hematological involvement, including anemia, leukopenia, lymphopenia, and thrombocytopenia, is one of the most common manifestations of childhood-onset systemic lupus erythematosus (cSLE). Specifically, relatively severe forms of hematological involvement, such as macrophage activation syndrome (MAS) and thrombotic microangiopathy, occur in the course of the disease. Positivity for anti-double stranded-DNA (ds-DNA) antibody and hypocomplementemia are important as not only criteria of diagnosing cSLE but also in the determination of the disease activity.

Case report: A 13-year-old boy without pre-existing disease was referred to our hospital chiefly complaining of a fever for > 7 days, long-lasting malaise, nausea, and non-malar face rash. His blood examination showed pancytopenia and hyperferritinemia, but positive results for anti-ds-DNA antibody and hypocomplementemia were not recognized. Bone marrow aspiration revealed no evidence of malignant diseases, hemophagocytic lymphohistiocytosis, or MAS. A renal biopsy for the differential diagnosis of proteinuria and hematuria revealed class IIIa +V lupus nephritis, leading to the diagnosis of cSLE.

Conclusions: It is important for cSLE to be considered in patients with pancytopenia, even those without positive anti-ds-DNA antibody findings or hypocomplementemia, and for aggressive approaches to be adopted for the differential diagnosis, including a renal biopsy.