Evolving concepts in prognostic scoring of chronic GvHD.

Chronic GvHD (cGvHD) remains one of the most complex and challenging complications after allogeneic hematopoietic cell transplantation. Emerging knowledge about the clinical manifestations and associated organ involvement of cGvHD has led to the establishment of prognostic parameters for post-transplant survival among affected allograft recipients. Studies employing the pre-National Institutes of Health (NIH) consensus data on cGvHD incidence and its risks have led to development of the CIBMTR's cGvHD risk stratification, which serves as the most refined and validated prognostic tool for estimating survival of patients with cGvHD. However, cGvHD global severity scoring has recently evolved as a powerful prognostic tool for patient survival in the post-NIH consensus era. Current use of the substantially redefined NIH criteria of cGvHD diagnosis and measurements of its severity makes it challenging to interpret prognostic scoring systems generated in the pre-NIH era. Some of the pre-NIH prognostic parameters, however, appear to retain their significance in predicting survival independently from the NIH global severity score. Thus, future analyses of prospective cohorts of patients with cGvHD defined by NIH consensus criteria will be critical in reconciling and integrating various prognostic scoring systems of cGvHD.