Viral encephalitis after allogeneic stem cell transplantation: a rare complication with distinct characteristics of different causative agents.
BACKGROUND
Limited data are available on characteristics of viral encephalitis in patients after allogeneic stem cell transplantation.


METHODS
We analyzed 2,628 patients after allogeneic stem cell transplantation to identify risk factors and characteristics of viral encephalitis.


RESULTS
Viral encephalitis occurred in 32 patients (1.2%, 95% confidence interval 0.8%-1.6%) and was associated with the use of OKT-3 or alemtuzumab for T-cell depletion (P < 0.001) and an increased mortality (P = 0.011) in comparison to patients without viral encephalitis. Detected viruses included human herpesvirus-6 (28%), Epstein-Barr virus (19%), herpes simplex virus (13%), JC virus (9%), varicella zoster virus (6%), cytomegalovirus (6%) and adenovirus (3%). More than one virus was identified in 16% of the patients. The median onset time was 106 days after allogeneic stem cell transplantation for the total group of 32 patients, but onset times were shortest in those with human herpesvirus-6 encephalitis and longest in those with JC virus-associated progressive multifocal leukoencephalopathy. The probability of a sustained response to treatment was 63% (95% confidence interval 44%-82%) with a median survival of 94 (95% confidence interval 36-152) days after onset, but significant variation was found when considering different causative viruses. Patients with herpes simplex virus encephalitis had the most favorable outcome with no encephalitis-related deaths.


CONCLUSIONS
The use of OKT-3 or alemtuzumab for in vivo T-cell depletion is associated with an increased risk of viral encephalitis after allogeneic stem cell transplantation. Different viruses are frequently associated with distinct characteristics such as onset time, response to treatment and outcome.
Schmidt-Hieber
Martin
M
Medizinische Klinik III (Hämatologie, Onkologie and Transfusionsmedizin), Charité Campus Benjamin Franklin, Berlin, Germany. martin.schmidt-hieber@charite.de
Schwender
Julie
J
Heinz
Werner J
WJ
Zabelina
Tatjana
T
Kühl
Jörn S
JS
Mousset
Sabine
S
Schüttrumpf
Silke
S
Junghanss
Christian
C
Silling
Gerda
G
Basara
Nadezda
N
Neuburger
Stefan
S
Thiel
Eckhard
E
Blau
Igor W
IW
D000293:Adolescent; D000328:Adult; D000368:Aged; D000074323:Alemtuzumab; D000911:Antibodies, Monoclonal / Q000627:therapeutic use; D061067:Antibodies, Monoclonal, Humanized; D000912:Antibodies, Neoplasm / Q000627:therapeutic use; D000970:Antineoplastic Agents / Q000627:therapeutic use; D000998:Antiviral Agents / Q000627:therapeutic use; D002648:Child; D002675:Child, Preschool; D003131:Combined Modality Therapy; D018792:Encephalitis, Viral / Q000188:drug therapy / Q000209:etiology*; D005260:Female; D006086:Graft vs Host Disease / Q000209:etiology*; D019337:Hematologic Neoplasms / Q000628:therapy; D018380:Hematopoietic Stem Cell Transplantation / Q000009:adverse effects*; D006801:Humans; D007166:Immunosuppressive Agents / Q000627:therapeutic use; D007223:Infant; D008212:Lymphocyte Depletion; D008297:Male; D008875:Middle Aged; D016853:Muromonab-CD3 / Q000627:therapeutic use; D012189:Retrospective Studies; D015996:Survival Rate; D014184:Transplantation, Homologous; D016896:Treatment Outcome; D014775:Virus Activation; D055815:Young Adult
D000911:Antibodies, Monoclonal; D061067:Antibodies, Monoclonal, Humanized; D000912:Antibodies, Neoplasm; D000970:Antineoplastic Agents; D000998:Antiviral Agents; D007166:Immunosuppressive Agents; D016853:Muromonab-CD3; D000074323:Alemtuzumab