STAT3 Hyper-IgE Syndrome-an Update and Unanswered Questions

The hyper-IgE syndromes (HIES) are a heterogeneous group of inborn errors of immunity sharing manifestations including increased infection susceptibility, eczema, and raised serum IgE. Since the prototypical HIES description 55 years ago, areas of significant progress have included description of key disease-causing genes and differentiation into clinically distinct entities. The first two patients reported had what is now understood to be HIES from dominant-negative mutations in signal transduction and activator of transcription 3 (STAT3-HIES), conferring a broad immune defect across both innate and acquired arms, as well as defects in skeletal, connective tissue, and vascular function, causing a clinical phenotype including eczema, staphylococcal and fungal skin and pulmonary infection, scoliosis and minimal trauma fractures, and vascular tortuosity and aneurysm. Due to the constitutionally expressed nature of STAT3, initial reports at treatment with allogeneic stem cell transplantation were not positive and treatment has hinged on aggressive antimicrobial prophylaxis and treatment to prevent the development of end-organ disease such as pneumatocele. Research into the pathophysiology of STAT3-HIES has driven understanding of the interface of several signaling pathways, including the JAK-STAT pathways, interleukins 6 and 17, and the role of Th17 lymphocytes, and has been expanded by identification of phenocopies such as mutations in IL6ST and ZNF341. In this review we summarize the published literature on STAT3-HIES, present the diverse clinical manifestations of this syndrome with current management strategies, and update on the uncertain role of stem cell transplantation for this disease. We outline key unanswered questions for further study.

Causes of death in hyper-IgE syndrome

BACKGROUND

Hyper-IgE syndrome (HIES) is characterized by recurrent pyogenic infections, eczema, increased serum IgE levels, and a variety of connective tissue and skeletal system abnormalities. Little has been published regarding the causes of death in these patients or pathologic findings.

OBJECTIVE

To identify the cause of death in patients with HIES and to describe pathologic findings in fatal HIES.

METHODS

We reviewed the medical records and autopsy slides of 6 patients with HIES with autopsies performed at our institution.

RESULTS

All 6 patients with HIES were women and ranged in age from 24 to 40 years. All patients had a history of cystic lung disease and had pneumonia at the time of death, with Pseudomonas aeruginosa and fungal organisms predominating. Pulmonary fungal vascular invasion with fatal hemorrhage was observed in 3 patients, and metastatic fungal disease to the brain was observed in 2 patients caused by Aspergillus fumigatus and Scedosporium prolificans. Four patients had evidence of renal tubular injury, which was likely from amphotericin B toxicity; 3 patients had glomerulosclerosis; and 1 patient had 2 kidney angiomyolipomas.

CONCLUSIONS

Our series highlights the important role Pseudomonas and Aspergillus species play in patients with HIES with cystic lung disease. Intensified antifungal and gram-negative bacterial prophylaxis need evaluation as possible strategies to prevent these infectious complications in patients with cystic lung disease.

CLINICAL IMPLICATIONS

Fungal and Pseudomonas infection of cystic lung disease in HIES may be life threatening, and the proper management and prevention of these infections need continued investigation.