Table 2

Summary of literature on IEL counts

Study	Methods	Number of biopsies	Upper range	Comments
Ferguson and Murray5	H&E staining, IEL/100 enterocytes, 7 µm sections	40	40	Used controls, coeliac & autoimmune conditions, incorrect about normally distributed IEL, highest IEL count recorded: 155
Batman et al14	H&E staining, 5 µm sections	8	33	Study of HIV enteropathy
Hayat et al12	H&E staining, 4 µm sections	20	25	Counts made on uninterrupted length of epithelium >500 EC, controls defined only by a ‘normal’ sugar permeability
Mahadeva et al15	H&E staining, 3 µm sections	29	22	Major interest in normal villi with IEL infiltrate. Really difficult to infer group numbers here
Kakar et al16	H&E staining	12	39	Interest in normal villi with IEL infiltrates
Veress et al11	H&E staining, 3 µm CD3+	64	H&E: 20 CD3+: 5–9	In H&E sections, if IEL to EC ratio >5:1, do CD3 count
Biagi et al13	H&E staining	17	45	Major interest in promoting villous tip counts
Lähdeaho et al30	H&E staining	76	26	No reasons given for this cut-off value: referred to Ferguson and Murray5 and Kuitunen et al31 who give no reference range
Nasseri-Moghaddam et al18	H&E staining, CD45+ cells	46	H&E: 46 CD45+: 47	Establishing normal criteria by histology and immunocytology
Siriweera et al32	H&E staining	75	8	Retrospective study on 38 control and 37 coeliac specimens. Inexplicably small upper ranges for both groups

Notes: Here are tabulated some of the principal papers concerned with IEL counts in normal and diseased intestinal mucosae. Once identified in this way, it comes as a surprise that our perceptions of normality and of the accepted distinctions between normal and abnormal are so precariously based. Furthermore, the emphasis in some papers has been on the abnormal (HIV enteropathy), or with reference to a specific aspect (such as villus tip IEL), whereas in others, the actual numbers of patients are unclear, or a worked mean IEL±SD is not given. The very small size of some of the groups analysed should also be noted, since that has a major impact on the statistical ranges and confidence limits offered as diagnostic (with permission from Marsh & Heal.22,
EC. epithelial cells; IEL, intraepithelial lymphocytes.