Hypochromia is an early marker of iron deficiency anaemia

ABSTRACT NUMBER: NESTAC MEDAL FOR MEDICAL STUDENTS_6

 

AUTHOR
Jeremy Cheong

MAIN ABSTRACT TEXT

Introduction
Microcytosis in iron deficiency anaemia triggers an urgent referral for investigation of suspected gastrointestinal cancers. This study evaluated whether the inclusion of hypochromia as a marker for iron deficiency would lead to earlier referrals.

Methods
Consecutive patients referred from primary care under the 2-week wait suspected gastrointestinal cancer pathway with unexplained iron deficiency anaemia between October 2019 and October 2020 were included. Results of red cell indices were obtained from an electronic platform for accessing laboratory test results (Sunquest ICE™, Version 5.4, Sunquest Information Systems). Mean corpuscular haemoglobin (MCH) of 27-32pg and mean corpuscular volume (MCV) of 80-102fL were considered normal.

Results
Seventy nine patients (32 men, 47 women) were included. Median (IQR) age was 73 (62-80) years. 67% (53/79) had a low MCH and 43% (34/79) had a low MCV at the time of referral. In the preceding months of referral (median [IQR] 4.3 [1.8-7.9] months) 64 patients had a full blood count performed of which 55% (35/64) had a low MCH and 20% (13/64) had a low MCV. The earliest available full blood count prior to referral (43 patients, median (IQR) of 16.5 (12-37) months) showed that 86% (37/43) had a low MCH compared to 33% (14/43) with a low MCV. A fall in MCH always preceded a fall in MCV at all the three time points analysed.

Conclusion
The inclusion of hypochromia as a marker of iron deficiency in the referral criteria for suspected gastrointestinal cancers would trigger significantly earlier referrals.