To the Editor:

In their audit, Tan et al. provide interesting insights on the epidemiology of giant cell arteritis (GCA), focusing on patients from the Indian subcontinent [1]. We have undertaken a similar audit at the Leicester Royal Infirmary, which is a tertiary referral centre in which all the temporal artery biopsies (TABs) are referred to the Ophthalmology Department. In our geographical area, Indians make up around 30% of the population, with around 6% of all Indians in England living in Leicester [2, 3]. All the TABs done by a single surgeon (JV) from January to August 2018 were analysed - this amounted to 35 TABs. These biopsies made up 71% of the total (49) TABs that were done over the same period within the department. Of the 35 patients undergoing biopsy, five (14%) were Indian and two (6%) were Arab, and none of them had a positive histology. On the other hand, 39% (11 out of 28) Caucasian biopsies were positive, with a mean age of 77 ± 9.7 years (range: 59–90 years). Overall, 64% of patients with positive biopsies were males. C-reactive protein (CRP) was elevated in all the patients with a positive biopsy (cut-off 15 mg/L), with a mean CRP level of 86 ± 76 mg/L (range: 16–239 mg/L). Plasma viscosity was elevated in 10 of 11 (91%) affected patients. Low haemoglobin and/or platelet count was present in 45% of biopsy-positive patients. Only one patient with temporal arteritis had transaminase (alanine aminotransferase, ALT) elevation; hence, the sensitivity of liver enzymes in GCA was 9% in our cohort. Interestingly, the patient with elevated ALT also had the most severe thrombocytosis, with a platelet count of 720 × 109/L (normal range: 140–400 × 109/L).

Shah and Jain have previous looked at GCA in Indians living in Leicester over a 5-year period [2]. They had also found that the incidence of biopsy-proven GCA in this ethnicity is low. As Tan et al. state in their discussion, GCA is rare but possible in Indians. Therefore, it is important to consider alternative diagnoses in this ethnic population. However, we agree that in some cases the diagnosis can be made clinically, even if not supported by the histological findings.