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Updated: Nov 17, 2025

Separation of Immune Cell Subpopulations in Peripheral Blood Samples from Children with Infectious Mononucleosis
Published on: September 7, 2022
[EBV-positive MTX-associated lymphoproliferative disorder and Ig M myeloma in rheumatoid arthritis]
Marie Wernecke1, David Frieling2, Ulrike Brandl3
1Klinik für Innere Medizin, Schönklinik Hamburg-Eilbek.
History:
An 80-year-old female patient arrived with a pronounced lymphadenopathy and weight loss. 6 years ago she had been diagnosed with rheumatoid arthritis. At the time of arrival, she was administered Methotrexate (MTX) 10 mg/week.
Findings And Diagnosis:
By lymph node biopsy, a clonal population of both EBV-positive B and T cells was seen. Newly occurring anemia (Hb 10 g/dl), monoclonal gammopathy of the Ig M isotype and detection of 40 % EBV-positive plasma cells in the bone marrow were consistent with the diagnosis of Ig M myeloma. We interpret these findings as a biclonal Epstein Barr Virus-positive Methotrexate-associated lymphoproliferative disorder (MTX-LPD).
Treatment And Course:
The clinical condition improved immediately after MTX discontinuation. In the follow-up after 4 months, the gamma globulin concentration in serum was significantly reduced (from 51.1 to 34.7 %) and a renewed immune electrophoresis of the serum was without evidence of monoclonal gammopathy.
Conclusion:
Based on this case, the association of RA with lymphoproliferative disorders can be confirmed - here as an association of RA with biclonal MTX-LPD or multiple myeloma. Therapy with MTX and reactivation of EBV infection are important influencing factors.

