Risk factors for herpes simplex virus-1/2 viremia and clinical outcomes following unmanipulated haploidentical haematopoietic stem cell transplantation.

BACKGROUND

Herpes simplex virus (HSV)-1/2 can still be reactivated after allogeneic haematopoietic stem cell transplantation (allo-HSCT) even when the prophylactic acyclovir is used. However, the risk factors for HSV-1/2 viremia and the clinical outcomes following unmanipulated haploidentical HSCT remain unknown.

OBJECTIVES AND STUDY

DESIGN

Nineteen patients with HSV-1/2 viremia and fifty-seven patients without HSV-1/2 viremia which were selected using the case-pair method after undergoing haploidentical HSCT were enrolled. We analysed the risk factors for HSV-1/2 viremia and compared the clinical outcomes between the two groups.

RESULTS

The risk factors for HSV-1/2 viremia included HLA disparity ≥2 loci (p=0.049) and cytomegalovirus (CMV) reactivation (p=0.028). The incidences of platelet engraftment, oral mucositis and severe haemorrhagic cystitis (HC) in patients with and without HSV-1/2 viremia were 77% and 94% (p=0.003), 78% and 13% (p=0.000), and 25% and 6% (p=0.04), respectively. Moreover, the median time to platelet engraftment in patients with and without HSV-1/2 viremia was +25days (range, +11-+80) and +17days (range, +8-+67) (p=0.004), respectively. According to the multivariate analyses, HSV-1/2 viremia was associated with delayed platelet engraftment (p=0.038), a higher incidence of oral mucositis (p=0.000) and severe HC (p=0.038). However, HSV-1/2 viremia was not associated with non-relapse mortality (34.0% vs. 31.5%, p=0.26), leukaemia-free survival (60.9% vs. 57.9%, p=0.46) and overall survival (61.2% vs. 60.7%, p=0.37).

CONCLUSIONS

Based on our study results, we recommend that HSV-1/2 PCR should be performed upon clinical suspicion of HSV-1/2 infection.