Automatic Reading of ANCA-Slides: Evaluation of the AKLIDES System

Abstract EN

The ANCA consensus prescribes screening by indirect immunofluorescence on neutrophils.

We evaluated the first automated ANCA-pattern recognition system.

C-ANCA (n=39) and P-ANCA (n=40) samples were selected from patients with ANCA-associated vasculitis (AAV).

Non-AAV controls included sera from healthy controls (n=40), sera with possible interfering antibodies (n=46), or miscellaneous ANCA reactivity (n=31).

ANCA slides were analysed by AKLIDES and routine fluorescence microscopy.

The C-ANCA pattern was recognized by routine microscopy in 92% and 97% on ethanol- and formalin-fixed slides, respectively.

AKLIDES reported C-ANCA in 74% and 95%, respectively.

P-ANCA was recognized by routine microscopy on ethanol-fixed neutrophils in 90%, while AKLIDES reported P-ANCA in 80%.

Typically, only 65% and 33% of these samples showed the expected C-ANCA on formalin-fixed neutrophils by routine microscopy and AKLIDES, respectively.

A C- or P-ANCA pattern was observed on ethanol-fixed neutrophils in 28% and 23% of the controls by routine microscopy and AKLIDES, respectively.

Only 5% of the controls revealed C-ANCA on formalin-fixed neutrophils by routine microscopy and AKLIDES.

Altogether, automated ANCA-pattern recognition by AKLIDES is promising.

Distinction of C- and P-ANCA is good, but sensitivity on ethanol-fixed neutrophils needs improvement.

When optimized, pattern recognition software may play an important role in AAV diagnostics.