Early detection of sjogren's test or lip biopsy more accurate?

[waif]

hi all

i am about to schedule a lip biopsy for sjogren's. i have severe neuropathy in both my hands/arms. the problem is my mouth is not dry at all..nose/eyes are extremely dry.

does anyone know how accurate this test is
http://www.bausch.com/ecp/our-products/diagnostics/sjo

vs a lip biopsy?

thank you.