NEQAS SCHEME 3

1
NEQAS SCHEME 3

• Cycle 1 2008 samples 301-06

2
NEQAS SCHEME 3

• Cycle 2 2008 samples 307-12

3
Class I

• Sample 301
• No real problems
• Sample 302
• No real problems

4

• Sample 303
• Most penalty points awarded for not reporting
  what might be considered weaker reactions against
  HLA-A antigens. Stronger reactions suggest Bw4
  specific antibody (which incidentally cannot be
  reported)

5

• Sample 304
• No problems with class I, all labs reported as
  negative

6

• Sample 305
• As with sample 303, lots of PPs for not
  reporting weaker reactivity (HLA-B antigens this
  time)
• Many labs had difficulty detecting B12 and B17
  Abs
• Many reported B76 as ve. No B62 or B70 Ab
  detected therefore unlikely (Bead anomaly)

7

• Sample 306
• Same story Lots of PPs for not listing weak
  specificities as positive
• Majority behaviour at the moment seems to be if
  its positive put it down

8

• Class II antibody analysis
• No real difficulties with any samples other
  than reporting of weak positive reactions

9
Cycle Performance

• All labs averaged 99
• Mostly for not reporting weak positives
  (?experienced vs novice luminex users)
• Large Nos PPs only apparent for CI ??
• CII all labs 11
• Most for not reporting weak positive

10

• Class I
• Sample 307
• A26 specific Ab caused problems for non-UK labs
• Cluster of UK labs had difficulty detecting B57

11

• Sample 308
• A25 specific Ab caused difficulty across the
  board
• Same cluster of UK labs had difficulty detecting
  B57 and B44 specific Abs

12

• Sample 309
• Same cluster of UK labs had difficulty detecting
  A9 and B17 specific Abs

13

• Sample 310
• A group of UK labs penalised for not detecting
  A29,32,43,66,74,80 B17,21,52,62 and 63 specific
  Abs. All weaker reactions

14

• Sample 311
• Split decision over /- B7
• 1 lab had real problems with this sample
• Failed to detect B13,38,44,49,63 and B77 specific
  Abs (all 5pps)

15

• Sample 312
• Same lab had problems with this sample
• Failed to detect A28,33,34 and B57specific Abs
  (all 5pps)
• Failed to detect B54 and B55 specific Abs (all 3
  PPs)
• This lab had problems with all samples and may
  need assistance/guidance
• 3 or 4 non-UK labs in similar position

16

• Class II
• Sample 311
• DQ9 specific Ab caused difficulty with some
  non-UK labs failing to detect (3PPs)

17

• Sample 312
• Problem with detection of DQ6 specific Ab. Same
  labs also penalised for not detecting DQ5
  specific Ab
• ? Problem with detecting DQ1?
• - Unlikely - labs not reporting DQ1 specific Ab
  probably using single antigen beads, given
  DR1,10,103 and DR51 specificities, multi antigen
  beads would not discriminate

18

• Overall Performance
• Big increase in PPs for Class I - ? Reflection
  of changes to scoring system
• Patterns of cycle performance perpetuated in
  2008 If you scored high number of PPs in 07
  then the same in 08 etc
• Patterns of scoring per cycle perpetuated also
  low score cycle 1 then high cycle 2 etc
• Overall not much has changed!
• Class II, general improvement from 07 despite
  change to scoring

19

• Questions
• Is it time to ignore 1pp scores and concentrate
  on the more disparate results?
• Why is class II so much less problematic?
• Does this reflect less antigens to report on Kit
  performance
• Is there a need for a forum to discuss what is
  considered a positive reaction?
• Is there a schism between experienced and novice
  users?
• Should we add clinical relevance to the scheme?