Treat Asia Quality Assurance Scheme

Supported by AMFAR and coordinated by the National Reference Laboratory in

AustraliaSally Land.

A Quality Assessment Scheme to Standardize the Outcome of HIV Genotypic Drug Resistance Testing in a group of Asian Laboratories

Sally Land1, Philip Cunningham2, Jialun Zhou2, Kevin Frost3, David Katzenstein4, Rami Kantor5, Allison DeLong5, David Sayer6, Jeffery Smith3, Elizabeth M Dax1 and Matthew Law2 on behalf of the TAQAS Laboratory Group. 1 National Serology Reference Laboratory, Australia, Melbourne, Victoria, Australia; 2 The National Centre in HIV Epidemiology and Clinical Research, Sydney, Australia; 3 The Foundation of AIDS Research, New York, NY, USA; 4 Stanford University, Stanford, CA, USA; 5 Brown University, Providence, RI, USA; and 6 Conexio Genomics, Fremantle, W.A., Australia.

9 panels in 23 labs, % detection

95

96

97

98

99

100

% N

ucle

otid

e s

eq

ue

nce

ag

ree

me

nt

TAQAS 1 TAQAS 2 TAQAS 3 TAQAS 4

0

20

40

60

80

100

% V

iral m

ixtu

res

dete

cted

TAQAS 1 TAQAS 2 TAQAS 3 TAQAS 4Lab ID 1 – 10 Lab ID 1 – 11 Lab ID 1 – 11 Lab ID 1 - 16

Participants demonstrated high level agreement at the nucleotide sequence level that was consistent with that reported in the literature (Figure 1) (5).

Participants maintained a high level of detection of DRMs that was consistent with the level of detection achieved in other EQAS (Figure 2) (6).

Participants’ detection of viral mixtures varied and correlated with detection of DRMs (Pearson’s r: p<.05), therefore ability to detect viral mixtures reflects, to a certain degree, the quality of testing (Figure 3).

Participants’ detection of viral mixtures may be influenced by the proportion of DRMs present as mixtures of mutant and wild type virus, nucleotide sequence quality and sequence editing.

Agreement in interpretation of ARV susceptibility may be increased when all participants use the same system.