THE VALUE OF DYNAMIC HEPATIC SCINTIGRAPHY AND SERUM AMINOTERMINAL PROPEPTIDE OF TYPE-III PROCOLLAGEN FOR EARLY DETECTION OF METHOTREXATE-INDUCED HEPATIC DAMAGE IN PSORIASIS PATIENTS

Oral methotrexate (MTX) is a highly effective drug for the treatment o f severe psoriasis. A limitation of this treatment is its potential he patotoxicity. In the present prospective study the Value of dynamic he patic scintigraphy (DRS) and serum aminoterminal propeptide of type II I procollagen (PIIINP) were investigated as screening methods for earl y detection of MTX-induced hepatic damage. These relatively non-invasi ve procedures were compared with the liver biopsy classification, unti l now the gold standard to assess MTX-induced liver damage. Twenty-fiv e MTX patients were studied. The mean cumulative MTX dose was 3.9 g (r ange 0.2-11.1 g). Twenty-one patients had a normal liver histology (gr ade I), three patients had steatosis (grade II), and one patient mild fibrosis (grade IIIA). Seven additional patients with non-MTX related hepatic cirrhosis were included as disease controls. DHS showed a clea r-cut separation between the portal contribution of the MTX patients w ith grade I liver histology, and that of all other patients, A portal contribution larger than 52% was associated with a >95% chance of norm al liver histology. If this cut-off value had been used to postpone th e liver biopsy, this would have resulted in at least a 55% reduction i n the number of biopsies in patients with a normal liver histology, DH S appeared to be very promising as a screening test to differentiate b etween the presence or absence of MTX-induced hepatic damage, but appe ared not suitable to grade the severity of hepatic damage, Although a global relationship was demonstrated between serum PIIINP concentratio n and hepatic damage, single measurements in individual patients were not reliable, The combination of PIIINP measurements with DHS had only a limited additional value above DHS alone. The present study indicat es that DHS has great promise for the detection of early MTX-induced h epatic damage, Pending further studies, regular liver biopsies remain mandatory for the safe prolonged use of MTX in psoriasis patients.