Up to 80% of HSCT recipients are noted to have BK viruria, but only 10-25% of all patients develop clinically significant cystitis, often causing severe pain and urinary obstruction. Risk factors for HC development and specifically, the relationship of BK viremia to subsequent HC have not been well defined.
In a case-control study of all adult AlloHSCT recipients at UNMC between 10/01/11 to 06/30/14 there were 8 patients who developed HC and 88 unaffected control patients in the first 100 post-transplant days. Frozen plasma samples that had routinely been collected weekly after transplant for CMV viral loads were thawed and tested for BK DNA viral load, expressed as log transformed values. Comparisons of clinical factors and BK viremia timing and quantitation were compared in cases and controls to identify risks for HC.
Symptomatic HC occurred in 8/96 (7.9%) of patients at a median of 34 days post-transplant. BK viremia either before or during symptoms was detected in all 8 (100%) HC patients and in 21/88 (23.8%) controls. BK viremia was detected a median of 8 days prior to HC clinical symptoms. The log of first positive viral load was not statistically significant predictor (p=0.39) of symptomatic BK. Median BK viral load peak was significantly higher for n=8 patients with HC versus n=21 viremic patients without HC (4.8 vs 6.6, p=0.02). HC patients were a median of 34 years old (interquartile range, 28-51) versus 52 years (interquartile range, 42.3-60.6) in asymptomatic controls (p= 0.02). Unrelated allogeneic BMT was significantly associated with HC (p=0.03). There was no difference in gender, conditioning regimen, underlying disease, presence of GVHD, CMV viremia, total peripheral platelet or lymphocyte count.
HC was significantly associated with BK viremia occurring before or during HC. Younger age and unrelated allogeneic BMT were found associated with HC. Significantly higher peak values were found in patients who clinically developed HC. Weekly monitoring of BK viremia may help to predict for BK HC based on high peak log-transformed values.
C. Gebhart, None
J. Meza, None
V. Shostrom, None
R. G. Bociek, None
A. G. Freifeld, Merck: Data Safety Monitoring Board , Consulting fee
Astellas: Data Safety Monitoring Board , Consulting fee
See more of: Poster Abstract Session