Protocol biopsy results in the first few weeks after liver transplantation sometimes display histologic features of acute cellular rejection (ACR).
This can occur even in the absence of significant clinical or biochemical dysfunction.
|32% of patients with histologic ACR on protocol biopsy had no associated biochemical graft dysfunction.
There is no clear consensus about the need to treat such cases with adjuvant immunosuppression.
In this systematic review, the authors from Auckland, New Zealand, describe the natural history of untreated histologic ACR in the absence of biochemical graft dysfunction.
The team performed an electronic search of the Medline, Embase, and Cochrane Library databases to select studies that reported protocol liver biopsies in the early posttransplant period, between 1983 to 2000.
They selected studies that identified patients with ACR on protocol biopsy, who were not treated with adjuvant immunosuppression, to form the basis of the study group.
Data from individual studies were extracted using standardized pro forma and pooled for descriptive analysis.
The research team identified 3431 studies, of which 516 were cited in full.
Of these, 15 studies met all of the inclusion criteria.
These 15 studies reported on 1566 patients who had protocol biopsies performed in the early posttransplant period, of which 67% had histologic evidence of ACR.
The team found that 32% of patients, with histologic ACR on protocol biopsy, had no associated biochemical graft dysfunction.
Furthermore, without treatment, only 14% of these patients subsequently developed biochemical graft dysfunction requiring adjuvant immunosuppression.
Steroid-resistant rejection and chronic rejection both had a prevalence of 4% in patients with untreated histologic ACR and no biochemical graft dysfunction.
Dr Adam Bartlett's team concluded, "Withholding adjuvant immunosuppression from patients with histologic ACR and no biochemical graft dysfunction seems to be safe, as long as graft function is carefully monitored".
"The rationale for performing protocol biopsies in the absence of biochemical graft dysfunction is questionable".
In a related article in the same publication, Drs George Therapondos and Peter Hayes, from Edinburgh, Scotland, discuss the above article.
They conclude, "Despite…the limitations of this retrospective analysis, we believe that it is safe to abandon routine posttransplant liver biopsies in patients with no evidence of biochemical graft dysfunction".
"The severity of the biochemical abnormality that triggers a biopsy is likely to be dependant on the time since transplantation and further studies to define this more accurately are clearly required".