Background and Aim: Chronic
giardia infection can lead to non-erosive
gastrointestinal disorders, including
protein-losing enteropathy (PLE). This report describes non-diarrheal PLE in chronic
giardiasis in children with defective humoral immunity. Methods: The retrospective report is related to 2 children known to have a monogenic inborn error of immunity. The first patient is a 13-year-old boy with
X-linked agammaglobulinemia (Patient-1), and the second is a 5-year-old boy with
NF-kB inducing
kinase (NIK) deficiency
infection. Frequency, growth status, and serum
immunoglobulin-G (
IgG) trough and
albumin levels were monitored (Patient-2). Results: Patient-1 had more frequency of
pneumonia but reported no symptoms of
gastrointestinal disease, including alteration of bowel habits, change in stool consistency,
nausea,
vomiting,
fatigue, bloating, and
abdominal pain. No clinical oedema on examination. His weight remains static at 19-20 kg for about 1.5 years. Simultaneously, hypoproteinaemia was noted (Figure-1). A trial of increasing
IVIG (0.7 - 1 g/kg) and the use of subcutaneous
immunoglobulin (0.2 g/kg) did not reverse the biochemical and clinical situation. Hypoproteinaemia workup revealed normal liver and kidney functions, normal cardiac function, and no
proteinuria. Interestingly, his upper endoscopy showed mild
duodenitis and the presence of giardia lamblia at the
luminal surface (Figure-2). Following this, a 2-week course of oral
metronidazole (7.5 mg/kg/dose BID) resulted in a restoration of therapeutic serum
IgG trough and
albumin levels. Additionally, the child's nutritional status improved, and the frequency of
respiratory infections dropped. In Patient-2, progressive hypoproteinaemia was noted over nine months. Similarly, no gastrointestinal complaints; however, the family reported foul-smelling semisolid stools with regular consistency. His
IgG trough level was 2 g/l, and his
albumin level was 20 g/l. Despite maximizing
IVIG, he developed two episodes of
pneumonia and once
otitis media. An empiric oral
metronidazole course resulted in the amelioration of symptoms and restoration of proteinemia. Meanwhile, faeces microscopy confirmed the presence of Giardia lamblia. Conclusions: Progressive hypoproteinaemia in children with humoral immunodeficiency is a clinical concern. Routine stool microscopy can identify
giardia infection despite the ambiguity of gastrointestinal symptoms in such patients. However, a trial of empiric
metronidazole therapy should be considered.