Early morning neutropenia in a patient with systemic lupus erythematosus

Abstract

skin rashes, had stopped taking it, and presented at our outpatient clinic. She was in mild distress and showed neck lymphadenopathy, erythema on the trunk, mild leukocytopenia (1800/μl), and neutropenia (1100/μl; band cells, 560/μl). No other hematological, liver function, or urinary abnormalities, renal dysfunction, or inflammatory signs were identified. She was admitted to our hospital the next day. On admission, she was afebrile and seemed in better condition than when seen at the outpatient clinic. Physical examination did not reveal any abnormalities of the cardiovascular or respiratory system, marked hepatosplenomegaly, or neurological abnormalities. Her lymphadenopathy and erythema were improved. The next morning, the peripheral neutrophil count was decreased, to 280/μl (band cells, 45/μl; total leukocytes, 1800/μl); a blood sample obtained later the same day, however, showed that the neutrophil count had risen to 1400/μl (band cells, not detected; total leukocytes, 2200/μl). On the 3rd and 6th hospital days severe neutropenia, i.e., 360/μl (band cells, 70/μl; total leukocytes, 1400/μl) and 260/μl (band cells, 130/μl; total leukocytes, 1400/μl), respectively, was found again, but in the second blood samples obtained on the same days the neutrophil counts were again increased, to 1060/μl (band cells, not detected; total leukocytes, 2500/μl) and 2580/μl (band cells, not detected; total leukocytes, 3400/μl), respectively. During the hospitalization, her general condition markedly improved and we identified no remarkably abnormal laboratory findings for cytomegalovirus pp65 antigen assay, anti-human herpesvirus-6 IgM antibody, Epstein–Barr virus-associated antibodies, anti-histone antibody, anti-dsDNA antibody, or anti-granulocyte antibody. However, a lymphocyte-stimulating test was positive only for Zonisamide, indicating that her symptoms including fever and skin rashes were evoked by allergic reactions for Zonisamide, rather than flare-up of SLE or viral infection. The severe neutropenia was identified only for the blood samples obtained at around 06:00h, not in the second samples, taken at around 10:00h, on the same days. (In our hospital, blood is usually sampled from in-patients at 06:00– 06:30, before breakfast). Thus, as we suspected diurnal