The anti-VLA-4 antibody natalizumab induces erythroblastaemia in the majority of the treated patients with multiple sclerosis.
The presence of erythroblasts in the peripheral blood is generally associated with severe underlying disorders. The anti-very late antigen-4 (anti-VLA-4) antibody natalizumab, which is approved for treatment of multiple sclerosis, mediates an increase in circulating haematopoietic stem cells and may also trigger erythroblastaemia. We investigated the prevalence of erythroblastaemia in sequential blood smears of 14 natalizumab-treated and 14 interferon-treated patients with multiple sclerosis. Erythroblastaemia was found in 13 natalizumab-treated subjects (93%), whereas all controls were negative (p<0.0001). Knowledge of this frequent side effect is crucial for the correct interpretation of blood smears in natalizumab-treated patients and to avoid unnecessary diagnostic procedures.
Central Laboratory, Hospital of the Brothers of St. John of God, Graz, Austria christoph.robier@bbegg.at.
Christoph
C
Robier
Department of Psychiatry, Hospital of the Brothers of St. John of God, Graz, Austria.
Omid
O
Amouzadeh-Ghadikolai
Department of Neurology, Hospital of the Brothers of St. John of God, Graz, Austria.
Claudia
C
Bregant
Department of Neurology, Hospital of the Brothers of St. John of God, Graz, Austria.
Josef
J
Diez
Department of Neurology, Hospital of the Brothers of St. John of God, Graz, Austria.
Klaus
K
Melinz
Central Laboratory, Hospital of the Brothers of St. John of God, Graz, Austria.
Manfred
M
Neubauer
Department of Neurology, Hospital of the Brothers of St. John of God, Graz, Austria.
Stefan
S
Quasthoff
D000328:Adult; D001317:Austria / Q000453:epidemiology; D016022:Case-Control Studies; D004900:Erythroblasts / Q000187:drug effects*; D005260:Female; D006402:Hematologic Diseases / Q000097:blood / Q000139:chemically induced* / Q000175:diagnosis / Q000453:epidemiology; D006801:Humans; D007155:Immunologic Factors / Q000009:adverse effects*; D039041:Integrin alpha4beta1 / Q000037:antagonists & inhibitors* / Q000276:immunology; D008297:Male; D008875:Middle Aged; D009103:Multiple Sclerosis / Q000175:diagnosis / Q000188:drug therapy* / Q000453:epidemiology / Q000276:immunology; D000069442:Natalizumab / Q000009:adverse effects*; D015995:Prevalence; D012307:Risk Factors; D016896:Treatment Outcome; D055815:Young Adult
D007155:Immunologic Factors; D039041:Integrin alpha4beta1; D000069442:Natalizumab
Erythroblastaemia; erythroblasts; multiple sclerosis; natalizumab