Mielke, Stephan

Abstract 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. Table 1. GVHD Target Organ Staging Stage Skin (active erythema only) Liver (bilirubin) Upper GI Lower GI (stool output/day) 0 No active (erythematous) GVHD rash < 2 mg/dl No or intermittent nausea, vomiting or anorexia Adult: < 500 ml/day or <3 episodes/day Child: < 10 ml/kg/day or <4 episodes/day 1 Rash < 25% BSA 2-3 mg/dl Persistent nausea, vomiting or anorexia Adult: 500-999 ml/day or 3-4 episodes/day Child: 10 -19.9 ml/kg/day or 4-6 episodes/day 2 Rash 25 - 50% BSA 3.1-6 mg/dl - Adult: 1000-1500 ml/day or 5-7 episodes/day Child: 20 - 30 ml/kg/day or 7-10 episodes/day 3 Rash > 50% BSA 6.1-15 mg/dl - Adult: >1500 ml/day or >7 episodes/day Child: > 30 ml/kg/day or >10 episodes/day 4 Generalized rash (>50% BSA) and bullous formation or desquamation > 5% BSA >15 mg/dl - Severe abdominal pain with or without ileus, or grossly bloody stool (volume independent) Table 2. Confidence Levels Pathologic evidence Clinician assessment Treatment for acute GVHD Comments Confirmed Unequivocal evidence of GVHD GVHD is the etiology for symptoms Not required GVHD is clearly present even if other etiologies co-exist simultaneously Probable Not required (includes equivocal and non-diagnostic biopsies) GVHD most likely etiology for symptoms Yes GVHD is most likely present but other etiologies may also explain the symptoms and there insufficient evidence to make a confirmed diagnosis Possible GVHD in differential diagnosis (but no treatment is being provided) No GVHD may be present, but other etiologies are favored Negative Unequivocal evidence of a diagnosis other than GVHD (e.g., drug rash) GVHD is not considered as an explanation for the symptoms No and the symptoms resolve without GVHD treatment A "negative" biopsy (e.g., normal skin) is not unequivocal evidence of a diagnosis other than GVHD Disclosures Devine: Genzyme: Research Funding. Chen:Bayer: Consultancy, Research Funding. Porter:Novartis: Patents & Royalties, Research Funding. Levine:Novartis: Consultancy.

BACKGROUND. No laboratory test can predict the risk of nonrelapse mortality (NRM) or severe graft-versus-host disease (GVHD) after hematopoietic cellular transplantation (HCT) prior to the onset of GVHD symptoms. METHODS. Patient blood samples on day 7 after HCT were obtained from a multicenter set of 1,287 patients, and 620 samples were assigned to a training set. We measured the concentrations of 4 GVHD biomarkers (ST2, REG3α, TNFR1, and IL-2Rα) and used them to model 6-month NRM using rigorous cross-validation strategies to identify the best algorithm that defined 2 distinct risk groups. We then applied the final algorithm in an independent test set ( n = 309) and validation set ( n = 358). RESULTS. A 2-biomarker model using ST2 and REG3α concentrations identified patients with a cumulative incidence of 6-month NRM of 28% in the high-risk group and 7% in the low-risk group ( P < 0.001). The algorithm performed equally well in the test set (33% vs. 7%, P < 0.001) and the multicenter validation set (26% vs. 10%, P < 0.001). Sixteen percent, 17%, and 20% of patients were at high risk in the training, test, and validation sets, respectively. GVHD-related mortality was greater in high-risk patients (18% vs. 4%, P < 0.001), as was severe gastrointestinal GVHD (17% vs. 8%, P < 0.001). The same algorithm can be successfully adapted to define 3 distinct risk groups at GVHD onset. CONCLUSION. A biomarker algorithm based on a blood sample taken 7 days after HCT can consistently identify a group of patients at high risk for lethal GVHD and NRM. FUNDING. The National Cancer Institute, American Cancer Society, and the Doris Duke Charitable Foundation.