# Challenges in diagnosis and management of pulmonary valve endocarditis associated with autoimmune lymphoproliferative syndrome (ALPS): A case report and literature review

## TL;DR

This case report highlights the rare and challenging diagnosis of pulmonary valve endocarditis in a patient with autoimmune lymphoproliferative syndrome (ALPS), emphasizing the need for early detection and tailored treatment.

## Contribution

The paper presents a rare case of pulmonary valve endocarditis associated with ALPS and emphasizes the importance of considering this condition in diagnostic evaluations.

## Key findings

- Pulmonary valve endocarditis is extremely rare and often difficult to diagnose with standard methods.
- The patient's condition improved with a combination of antibiotics, immunoglobulin, and corticosteroids, followed by valve replacement.
- ALPS should be considered in patients with persistent lymphoproliferation and unexplained febrile illness.

## Abstract

Isolated infection of the pulmonary valve is rarely encountered. The diagnosis is not considered based on clinical presentation or even on transthoracic echocardiography. A conservative approach is generally recommended for most patients with infective endocarditis. Our patient also had an autoimmune lymphoproliferative syndrome (ALPS), described as a rare hereditary disorder of lymphocyte homeostasis, resulting from mutations in the Fas apoptosis pathway. The elevated level of double-negative T cells (DNT) is considered a major diagnostic marker for this rare pathology. An 18-year-old female was admitted to our institution for prolonged febrile illness persisting for 2 years. She also suffered from respiratory symptoms for 2 months treated with amoxicillin without clear amelioration. After a thorough assessment, the patient was diagnosed with pulmonary valve endocarditis associated with autoimmune lymphoproliferative syndrome. Appropriate management, started by empirical antibiotics then intravenous immunoglobulin and prednisolone. Our patient underwent after 6 months of the follow up, pulmonary valve replacement by bioprosthesis. Endocarditis of the right side of the heart mostly affects the tricuspid valve, especially in cases involving drug users. Isolated infection of the pulmonary valve is rarely encountered. Accurate and early diagnosis of pulmonary valve endocarditis is essential for implementing appropriate management strategies. The autoimmune lymphoproliferative syndrome (ALPS) is a rare hereditary disorder of lymphocyte homeostasis, resulting from mutations in the Fas apoptosis pathway. Lymphoproliferation is the most common manifestation in ALPS, illustrated by lymphadenopathy, splenomegaly, and/or hepatomegaly persisting for over 6 months. Right‐Sided Infective Endocarditis affecting only the pulmonary valve is very rare. It should be considered to investigate for right-sided infective endocarditis and echocardiography leads the diagnosis.