Terminal hepatic venule injury in liver biopsies of allogeneic haematopoietic stem cell recipients-a study of 63 cases

Aims: Subtle lesions of terminal hepatic venules (THVs) may be overlooked in liver biopsies from haematopoietic stem cell transplant (HSCT) receipients when graft-versus-host disease is the clinical concern. The aim of this study was to evaluate the frequency of THV injury resembling sinusoidal obstruction syndrome (SOS). Methods and results: Sixty-three consecutive biopsies from allogeneic HSCT recipients were scored for injured THVs. Forty-nine (78%) biopsies had injured THVs, and 10 (16%) were diagnosed with SOS (mean ± standard deviation of injured THVs/biopsy: 90 ± 9%). Biopsies diagnosed with other diseases also had injured THVs (36 ± 33%). Biopsies from patients with cyclophosphamide plus fractionated total body irradiation conditioning and biopsies taken within 100 days post-HSCT had significantly more occluded THVs (respectively: 40 ± 38%, P = 0.0188; and 35 ± 35%, P = 0.0076) than those with other conditioning regimens or in biopsies taken >100 days post-HSCT. All biopsies taken at any time in the 6-year post-HSCT period had similar amounts of THV phlebosclerosis (23 ± 25%). Conclusions: Our results demonstrate a high incidence of THV injuries resembling SOS in post-HSCT liver biopsies. THV injuries were detectable for several years post-HSCT, and were concurrent with other diagnoses. Our results also suggest that SOS may be underdiagnosed.