T depletion is associated to an higher risks of encephalitis in adults patients receiving allogeneic haemopoietic stem cell transplantation

A.A. Colombo (1), C. Pascutto (1), E. Marchioni (2), F. Ripamonti (1), A. Di Matteo (1), F. Baldanti (1), M. Furione (1), E.P. Alessandrino (1)

Author address: 

(1)Fondazione IRCCS Policlinico San Matteo (Pavia, IT); (2)Fondazione Casimiro Mondino (Pavia, IT)


Aim of study was to identify if encephalitis represents an emerging complication in patients receiving allogeneic Hemopoietic stem cells Transplantation (HSCT). Methods: To identify the occurrence, the spectrum and the risk factors inducing neurological diseases, we carried out a retrospective cohort study including 391 adult patients followed up after allogeneic HSCT. All patients were affected by oncohematological diseases and received transplantation between January 1997 and June 2011. One hundred nine patients received an in vivo T depletion by ATG or Alemtuzumab. Results: Encephalitis was documented in 18/391 patients (4,6%) and occurred as an early complication in 10/18 pts. The time-trend of encephalitis incidence is illustrated in Figure 1, showing a fast increase since 2008. The percentage of patients receiving T depletion in the same period is also indicated. Vascular diseases were the most frequent causes of encephalitis (39%). Infectious encephalitis was reported in 11% of patients. Detected agents were represented by: CMV 1 pt; HHV6 1 pt; Aspergillus 2 pts, and Pseudomonas 1pt. Two patients developed a late toxic encephalic disease related to radiotherapy, one patient had a cerebral vasculitis and one a posterior reversible encephalopathy. The etiology of encephalitis was not identifi ed in 3 patients. Sixteen patient affected by encephalitis died, but encephalitis was the direct cause of death in only 13 patients. Univariate logistic regression models for potential risk factors identifi ed T-cell depletion (OR=7.5, p=0.001), time of transplant (3-year calendar periods of transplant, linear trend between 1997-2011) (OR=2.3, p=0.001) and unrelated donor (OR=3.5, p=0.001), as signifi cant risk factors. In multivariate logistic analysis including also disease status at transplantation, conditioning regimen and acute Graft versus Host Disease, T-depletion (OR=3.9, p=0.017) and time of transplant (OR=2.5, p= 0.002) were the only signifi cant risk factors for encephalitis. Conclusions: Our analysis confi rms a strong association between the use of in vivo T cell depletion and risk of encephalitis. Moreover, the increasing time-trend in incidence of encephalitis could be associated to a more frequent use of T depletion in our Centre in the last decade.

abstract No: 


Full conference title: 

Annual Meeting of the EBMT, 38th
    • EBMT 38th (2012)