Discussion
TTP is a particular form of thrombotic microangiopathy, characterized in
its typical form by the combination of five manifestations: central
nervous system damage, fever, renal failure, hemolytic anemia and a
consumer thrombocytopenia [1]. A deficiency in a disintegrin and
metalloprotease with thrombospondin type 1 repeat-13 (ADAMTS13) protein
leads to the plasma accumulation of megamultimers of Von Willebrand
Factor, and thus to platelet hyperaggregability at the origin of
microthrombi. These megamultimers are released by activated endothelial
cells, usually following an infection, drugs, neoplasias or pregnancy
[2]. ADAMTS13 deficiency may be the result of mutations in the gene
encoding the protein, resulting in the hereditary TTP observed in
children. In adults, ADAMTS13 deficiency is typically acquired and due
to the presence of autoantibodies which alter the activity of the
protein [3], such as our patient. TTP can also be associated with
different autoimmune diseases as in particular acute systemic lupus
erythematosus and isolated antinuclear antibodies can be found in two
thirds of cases [4]. It is common to find an episode of infectious
disease which preceded PTT by few days [5]. Many viruses have been
associated with an episode of PTT, as in particular the immunodeficiency
human virus [6]. Many usually prescribed medications have been
associated with the development of TTP. Ciprofloxacin seems to be an
emerging cause of drug-induced TTP, but unlike our case, rarely leads to
fatal complications [7]. However, there are no standards to
incriminate the drugs as the probable cause of TTP [8].
The prognosis of TTP has considerably improved after the introduction of
plasma exchange (50–75 mL/kg) once daily using fresh-frozen plasma
[9]. It is the only scientifically recognized treatment modality for
acquired TTP [10]. Corticosteroid therapy (methylprednisolone 1000
mg once daily) is also administered in conjunction with plasma exchange.
Other reports show that the monoclonal anti-CD-20 antibody rituximab
(375 mg/m2 once weekly for four doses) is effective in patients with
refractory or relapsed TTP [11]. With this protocol, our patient did
not respond to the treatment. Some authors explain the refractory
response to treatment or relapse due to a number of factors, such as
severe thrombocytopenia, age over 60 years, the presence of ADAMTS13
deficiency or inhibitor [12].
Our observation is particular due to the onset of a fatal TTP in a
patient with dermohypodermitis treated with ciprofloxacin. Through this
case, we would like to alert practitioners to this rare but
life-threatening entity in order to establish an early diagnosis to
improve the patient’s prognosis and survival in TTP.