INTESTINAL LYMPHANGIECTASIA AS A SECONDARY CAUSE OF ABNORMAL TREC SCREEN

Abstract

<h3>Introduction</h3> Less than 5 percent of abnormal T-Receptor Excision Circles (TREC) results have been associated with gastrointestinal anomalies. This case describes the presentation and work up of a patient with intestinal lymphangiectasia who presented as a TREC referral <h3>Case Description</h3> A 6-week-old male born at 38-weeks of gestation was referred to the Immunology service for low TRECs of 53. Total lymphocyte count was 3.4 k/ul, CD3 count was 1760, CD4 was 636, CD8 was 1000. He had a ratio of 52% RA and 48% RO with a reverse CD4:CD8 ratio (0.58), raising concern for possible infectious etiology and or leaky SCID . His PHA was normal, ruling out SCID. Infectious work up was sent and negative. IgG was 282 mg/dl, IgM 29.7, and IgA 31. Microarray showed a normal XY male with no deletions or duplications. A PID panel was sent and did not identify a diagnosis. At 3 months of life, he was noted to have swelling of the right arm, raising concern for possible lymphatic malformation or lymphangiectasia. Liver ultrasound was performed showing moderate ascites throughout the peritoneum and bowel wall thickening in the right upper quadrant. Albumin was low. EGD and colonoscopy confirmed intestinal lymphangiectasia affecting small bowel and colon. Evaluation was expanded to WES and targeted sequencing of affected gut tissue was unsuccessfully attempted. <h3>Discussion</h3> This case demonstrates how an abnormal TREC screen can pick up secondary causes of T cell lymphopenia. Early clues in this case included subtle asymmetry of his limb, low albumin, normal PHA and low RA.