Chronic
graft-versus-host disease (cGVHD) is a common and potentially lethal complication of
allogeneic hematopoietic stem cell transplantation (HSCT). cGVHD as well as the transplant procedure itself (
chemotherapy with or without
radiotherapy) can lead to the degradation of
connective tissue components such as
elastin and
collagen. The
catabolism of these structural proteins releases
desmosine (DES), lysylpyridinoline (LP), hydroxylysylpyridonoline (HP), and related pyridinium-based
cross-linkers analogues that could represent potential biomarkers for cGVHD. This study reports the development of a sensitive
liquid chromatography/tandem
mass spectrometry method for the simultaneous analysis of N-propyl derivatives of DES, HP, and LP. The concentrations of free and total forms of
urinary DES, HP, and LP were determined using synthetic
deuterated internal standards. This method enabled
accurate quantitation of these pyridinium-based
cross-linkers from as little as 100 muL of
urine with detection limits of 0.03-0.10 ng/mL. These compounds were analyzed in
urine samples from three groups of patients: (1) Healthy volunteers, (2)
Autologous HSCT recipients (who cannot develop cGVHD), and (3)
Allogeneic HSCT recipients at onset of cGHVD. These analyses revealed that the
urinary concentrations of DES, HP, and LP in the
autologous recipients were greater or equal to the cGVHD group although both groups showed marked increase in the levels of these compounds compared to healthy individuals. These results suggest that the
chemotherapy treatment has significant effects on the turnover of
elastin and
collagen, and that these biomarkers could be effective during prospective analyses to determine the onset of cGVHD.
