Guidelines for the Standardization of Acute Graft-Versus-Host Disease Clinical Data Collection: An International Consensus Report

Clinical GVHD staging varies between centers and is not agreed upon by independent reviewers (Weisdorf, BBMT 2003). These inconsistencies help explain why promising GVHD treatments from single center studies have not reproduced in multicenter trials. To address this issue, our international GVHD research consortium has developed guidance that has been refined through consensus following case discussions, resulting in uniform and reproducible GVHD clinical symptom reporting.

We record all raw target organ symptom data and apply staging based upon this data (Table 1). Only areas of erythema, bullae and desquamation are quantified because other skin changes are not typical of active GVHD rash. Upper GI symptoms must meet thresholds to diagnose GVHD: anorexia with associated weight loss, nausea and/or 2+ vomiting episodes/day lasting 3+ days. For lower GI GVHD we collect stool volumes excluding formed/mostly-formed stools. Unquantified episodes are counted at 200 ml per episode (3 ml/kg for children <50kg) based upon a chart review of 300 patients with post-BMT diarrhea from any cause. Non-GVHD rectal bleeding that results in flecks or streaks of blood in the stool are ignored for staging. We use the highest daily stool output in the 3 days prior to the diagnosis of lower GI GVHD to determine onset stage and, when available, a 3-day average stool volume for subsequent staging to smooth daily variability.

We classify biopsy report interpretation into four standardized categories: Positive (unequivocal presence of GVHD), Equivocal (findings suggestive of GVHD, but the pathologist cannot confirm the diagnosis), Non-diagnostic (no abnormalities or subtle findings insufficient to determine etiology), and Non-GVHD etiology (definitive evidence of another diagnosis without concomitant features suggestive of GVHD). We then combine the biopsy interpretation with clinical decision making to assign an overall confidence level to the diagnosis of GVHD in each target organ (Table 2): Confirmed (positive biopsy, regardless of clinician treatment decision), Probable (GVHD diagnosis is sufficiently favored that treatment is given without a positive biopsy), Possible (symptoms present without a positive biopsy; not treated as GVHD), Negative (no symptoms or symptoms are present but a GVHD diagnosis is not entertained and a non-GVHD etiology is identified).

Uniform clinical data collection is essential for future GVHD trials and requires application of clear guidance. While still subject to refinement, these guidelines, in use for 2 years by an international research consortium, are designed to be clear, easy to apply, and for clinical trial use.