I suggest you check the HbA1c methodology.
We had a family of patients with Hb variant Sinai Baltimore which caused a marked reduction (completely analysis generated) in HbA1c by ion exchange.
Sometimes the automatic algorithm was completely at odds with the opinion of a human observer.
This was not exhibited by fructosamine or total glycated Hb assays.
We now have a collection of patients with other variants (not all identified, since too many for Haematology to cope with) which cause disruption of the chromatogram.
This disruption was also noted to be variable between ion exchange analysers (BioRad Variant II vs Variant Turbo)
As a consequence, all chromatograms are quickly examined for gross abnormalities
with best wishes
Richard
Richard Mainwaring-Burton
Consultant Biochemist
Lewisham & Greenwich Healthcare Trust
Queen Elizabeth Hospital, Woolwich
SE18 4QH
020-8836-5724
mob: 07831-739876
From: Clinical biochemistry discussion list [mailto:[log in to unmask]]
On Behalf Of Al-Bahrani Ali
Sent: 11 September 2014 13:28
To: [log in to unmask]
Subject: Disparate blood glucose vs. HBA1c/Frustosamine
Dear Colleagues
I would welcome your comments and advise on the interesting case below please. 60 years old gentleman refer to the diabetic clinic because of disparate fasting/random glucose vs. very normal HBA1c please. Chemistries below please. Apparently he is not glycating
his proteins, possible evolving diabetes …..
Kind Regards
ALi
Dr Ali Al-bahrani
MBCh.B MSc.Chem Path. EuClin.chem. CSci. FRCPath.
Lead Pathologist
RCPath Wessex Professionalism Lead
Consultant Chemical Pathologist and HOD of Chemical Pathology
St Mary's Hospital
Newport
Isle of Wight
PO30 5TG
United Kingdom
Te: 01983 534859/534917
Collected 15.04.14 07:42 A.Diag
----------------------------------------------------------------------------
......Fast.gluc..........
Fast.Gluc. + 9.7
......Hb A1c.............
HbA1c - 19
Specimen B,14.0700164.T Clin dets High Fasting glucose and low HBA1c
Collected 01.04.14 08:11 A.Diag
----------------------------------------------------------------------------
......GTT................
Time 1 0 mins
Bl.Glucose 8.4
Time 2 120 mins
Bl.Glucose 15.9
Collected 29.05.14 08:12 A.Diag
----------------------------------------------------------------------------
......U&E................ |Free T4 10.8 |
Urea 5.5 |......Hb A1c............. |......LFT................
Sodium 138 |HbA1c 20 |ALT 32
Potassium 4.1 HDL Chol........... |Bilirubin 17
Chloride 103 |HDL Chol. - 1.09 |Alk. Phos. 71
Anion Gap NA |Cholestrol 3.82 | Tot.Prot. 67
Creatinine 95 |Trig. 1.57 |Albumin 40
eGFR - 75 |T/HC ratio + 3.50 |Globulin 27
......TFT................ | LDL(calc.) 2.01 |...... .......
Analyte Result Units Ref.Range |
| MCH 31.3 pg (28.0-34.0) |
| Reticulocytes 1.4 % (0.2-2.0) |
| RETIC ABSOLUTE 62 x10^9/l (20-80) |
| |
| Thalassaemia/Haemoglobin variant screening |
| Haemoglobin A2 2.5 % (2.0-3.3) |
| Haemoglobin F <0.8 % (0.0-1.0) |
| No atypical peaks seen |
| MCH 31.3 pg (28.0-34.0) |
| |
| Blood film: Blood film review supports automated cell count. |
| Thalassaemia Screen: No evidence of an abnormal
Collected 10.06.14 07:50 A.Diag
----------------------------------------------------------------------------
......U&E................ | |T/HC ratio + 4.37
Urea 4.7 |......Ferritin........... |LDL(calc.) 2.39
Sodium 137 |Ferritin 199 |......LFT................
Potassium 4.1 |......FRActasmine............... |ALT 26
Chloride 102 |FRUC 231.0 |Bilirubin 15
Anion Gap NA |Date ref. 11.06 |Alk. Phos. 64
Creatinine 88 |......HDL Chol........... |Tot.Prot. 65
eGFR - 82 |HDL Chol. - 0.93 |Albumin 39
......Glucose............ |Cholestrol 4.06 |Globulin 26
Glucose 7.0 |Trig. 1.61 |
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