A Rare Case of Recurrent Pneumonia in Heterotaxy Syndrome, Polysplenia/Left Isomerism

Abstract

Heterotaxy syndrome (HS) or situs ambiguous refers to the abnormal arrangement of viscera across the body axis, and abnormalities arise depending on the isomerism of the right or left atrial appendage. The cause remains unexplained and is attributed to a combination of genetic mutations and environmental factors. It is a rare condition and may remain undiagnosed for a long time. In this report, we aim to highlight an unusual presentation and aggravation of an infection due to the underlying isomerism of the left atrial appendage. We discuss the case of a female patient who presented with symptoms of fever and cough. The patient underwent prolonged antibiotic treatment, and her recovery was slow. The presence of bilobed lungs, vertical left-bronchus, and polysplenia on CT scan explained the left-sided aspiration pneumonia. The hypofunctioning spleen (polysplenia) caused her to have a weak immunological response, necessitating prolonged antibiotic use. She was followed up over time and had a recurrence of pneumonia within a few months. The condition is associated with high morbidity and mortality, and the role of early diagnosis and reporting to prevent complications is paramount. The recurrent pneumonia observed in the patient also raises questions related to long-term antibiotic use and immunization in the case of polysplenia in this patient population.

Anatomy, embryology, and imaging of situs ambiguous with polysplenia and left IVC

“…This ciliary dynamic generates an increase in Ca2+ entry through calcium channels (Ca2+) Polycystin 2 and the consequent activation of the Nodal gene. This is the signal that sets in motion the mechanisms that culminate in the asymmetric distribution of organs in the human anatomy [7] . The correct accomplishment of this process culminates with the normal development and positioning of the organs in the thorax and abdomen, called situs solitus.…”

“…As all malformation syndromes, the etiopathogenesis is multifactorial, a series of risk factors have been described that favor its development [12] and a series of genes related to its pathogenesis have been identified [7] . The most important of these are: Cocaine use in the first trimester Family history of congenital heart defects.…”

“… Mutations in the ZIC3, NODAL, CFC1, ACVR2B, LEFTY2, CITED2, and GDF1 genes have been associated with the development of heterotaxia. The inheritance pattern is varied and all are related to growth factor beta3 synthesis [7] . …”