OBJECTIVE: To evaluate tear film osmolarity (TFO) as a diagnostic tool for detecting chronic ocular graft-versus-host disease (GVHD) in patients after hematopoietic stem cell transplantation and to assess its correlation with the new international chronic ocular GVHD score.
METHODS: A group of 204 consecutive patients who underwent hematopoietic stem cell transplantation at University Hospital Wuerzburg in Germany received an ophthalmologic examination after transplantation. TFO was measured and the chronic ocular GVHD score was calculated based on the Schirmer test, corneal fluorescein staining, conjunctival injection, Ocular Surface Disease Index questionnaire, and presence of systemic GVHD.
RESULTS: A total of 172 patients showed no chronic ocular GVHD. Of the remaining 32 patients using the international chronic ocular GVHD score, 21 were classified as \"probably\" and 11 as \"definite\" chronic ocular GVHD. TFO was positively correlated with the new chronic ocular GVHD score (P < 0.01, r = 0.35). TFO differed significantly between patients with no ocular GVHD (300 ± 16.5 mOsm/L) and definite ocular GVHD (337 ± 36 mOsm/L)-a receiver operating characteristic analysis showed high discrimination capability (area under the curve: 0.91 ± 0.04) and suggested a threshold level of the TFO value of 312 mOsm/L yielding a sensitivity of 91% and a specificity of 82%.
CONCLUSIONS: TFO can be used for detecting chronic ocular GVHD with high sensitivity and specificity as a noninvasive objective test in addition to traditional dry eye tests. It correlates positively with the diagnostic criteria of a recently established international consensus score for diagnosing the disease.

The rate of dissociation of recombinant, purified human estrogen receptor alpha (ERalpha) from a fluorescein-labeled DNA containing the consensus vitellogenin ERE sequence (F-vitERE) was determined in real time using fluorescence anisotropy. The complex of estradiol-occupied ERalpha with F-vitERE had an apparent dissociation rate of 1.48+/-0.06x10(-2) s(-1) and a half-life of 46.6 s at room temperature. The dissociation rate was characterized by a single exponential decay, suggesting that ER dissociates from the DNA as a preformed dimer, rather than as two individual monomers. The association rate of estradiol-occupied ERalpha for the F-vitERE was calculated as 7x10(6) M(-1) s(-1) based on the dissociation rate measured and previous determinations of the equilibrium dissociation constant (Kd) in similar assay conditions (Ozers et al., 1997). In buffer containing various concentrations of salt, the rate of dissociation of estradiol-occupied ERalpha from F-vitERE was accelerated by increasing salt concentrations. Compared to estradiol-occupied ERalpha, the rate of dissociation of unoccupied ERalpha from the F-vitERE was very similar, indicating that estradiol occupancy does not affect the dissociation rate of ERalpha from the ERE.