Psoriasis monitoring for Patients on Methotrexate

Diagnostic accuracy of noninvasive markers of liver fibrosis in patients with psoriasis taking methotrexate: a systematic review and meta-analysis. Maybury CM. et al. Br J Dermatol. 2014 Jun;170(6):1237-47. doi: 10.1111/bjd.12905.

In classical textbooks it is said that because of the risk of liver fibrosis a liver biopsy should be performed after a cumulated methotrexate (MTX) dose of 1.5g.

This has somewhat been relaxed since ultrasound monitoring, blood samples: liver function tests (LFT) and pro collagen III  (PIII) dosage.

However as this study suggests, the three mentioned methods seem NOT to be enough:

• this is a retrospective review using MEDLINE, Embase, CINAHL, the Cochrane Library and
  Clinical Trials Register of patients taking or being considered for MTX
• out of the 17 studies included:
  • liver fibrosis was only detected in around one third abnormal of LFTs and  (Sensitivity (SE, true positive rate) and specificity (SP, true negative rate) were 38% and 83%)
  • liver fibrosis was detected in three quarters of cases with abnormal PIII dosage (74% and 77%)
  • fibroscan (non invasive liver imaging) effectively ruled out fibrosis in 80% of cases (80%SP and 60%SE)
  • ultrasound came out to be the less reliable method with a 55% Sensitivity and 49% Specificity

To conclude:
-none of the methods used in isolation are reliable in monitoring patients on MTX in search of liver fibrosis
-a visual analysis (morphology) is necessary and is most useful possible through liver biopsy.

Comments
-It could be interesting to measure Sensitivity and Specificity when combining 2 or more methods

Article selection: Prof Dr Jean-Hilaire Saurat – dermatologist. Geneva, Switzerland