Review article: non-malignant haematological complications of anti-tumour necrosis factor alpha therapy.
BACKGROUND
Tumour necrosis factor-alpha (TNF-α) is an important mediator of the molecular cascade leading to chronic inflammation. TNF-α inhibitors have proven their safety and efficacy in the treatment of inflammatory diseases.


OBJECTIVE
To review the non-malignant haematological adverse events, such as thrombocytopaenia, neutropaenia, hypercoagulability, pancytopaenia and aplastic anaemia in patients receiving TNF-α inhibitors.


METHODS
We reviewed the literature by searching MEDLINE and EMBASE databases as well as references of all retrieved articles for the following terms: anti-tumour necrosis factor, anti-TNF, infliximab, adalimumab, certolizumab, etanercept, haematological complications, thrombocytopaenia, neutropaenia, anaemia, bone marrow and thrombosis.


RESULTS
Thombocytopaenia is a very rare phenomenon and was associated with no serious adverse events. However, transient neutropaenia developed in up to 16% of cases. Patients with a previous history of neutropaenia on other therapies or baseline neutrophil count <4 × 10(9) /L are at a particularly higher risk. The association between anti-TNF-α therapy and thrombosis is very nebulous due to the multitude of potential confounders. Only one case of primary eosinophilia has been reported with anti-TNF-α therapy.


CONCLUSIONS
Regular monitoring of the white blood cell count at baseline and with each infusion is recommended for patients on anti-TNF-α. Further studies to elucidate their interaction with the immune system are warranted.
Department of Gastroenterology, University Hospital Gasthuisberg, Leuven, Belgium. talat.bessissow@mcgill.ca
T
T
Bessissow
M
M
Renard
I
I
Hoffman
S
S
Vermeire
P
P
Rutgeerts
G
G
Van Assche
D000740:Anemia / Q000139:chemically induced; D001791:Blood Platelet Disorders / Q000139:chemically induced; D004802:Eosinophilia / Q000139:chemically induced; D006402:Hematologic Diseases / Q000139:chemically induced*; D006801:Humans; D009503:Neutropenia / Q000139:chemically induced; D013927:Thrombosis / Q000139:chemically induced*; D014409:Tumor Necrosis Factor-alpha / Q000009:adverse effects / Q000037:antagonists & inhibitors*
D014409:Tumor Necrosis Factor-alpha