History: A 27-year-old woman from Cameroon was admitted because of arthralgia, myalgia and severe thrombocytopenia (20,000/ micro l). She had been suffering from weakness, recurrent febrile episodes, generalized lymphadenopathy and pancytopenia for 2 years. Having a typical autoantibody constellation and fulfilling four (pleurisy, autoimmune-hemolytic anemia, antinuclear antibodies (ANA), anti-Sm antibodies) of the American College of Rheumatology (ACR) classification criteria, systemic lupus erythematosus (SLE) had been diagnosed at another hospital. Treatment with corticosteroids and azathioprine did not improve her condition.
Investigations: Abnormal laboratory findings were pancytopenia, elevated markers of inflammation and extreme hypergammaglobulinemia (70 %) with polyclonal IgM (73 g/l). Antinuclear antibodies (ANA), anti-Sm-, anti-Scl 70-, anti-U1-RNP-, anti-histo-, anti-leukocyte- and IgM anticardiolipin antibodies were detected. A bone marrow biopsy showed polyclonal B-cell and plasma cell infiltrates. Examination of peripheral blood smears disclosed trypanosoma brucei infection.
Diagnosis, treatment and course: After the diagnosis of stage 2 West African trypanosomiasis (sleeping sickness) specific treatment was initiated leading to subsequent remission of the disease.
Conclusion: This case report underlines the importance of a thorough differential diagnosis in cases of suspected autoimmune disease. Induction of autoantibodies during infectious diseases may be misleading. The use of the ACR criteria for SLE must be restricted to the classification of proven connective tissue diseases.