Prevalence of GLA gene mutations and polymorphisms in patients with multiple sclerosis: A cross-sectional study

Aseptic meningitis and Fabry disease

OBJECTIVE

Fabry disease is caused by enzymatic defects in alpha-galactosidase A that leads to the accumulation of glycosphingolipids throughout the body, resulting in a multisystemic disorder. The most common neurological manifestations are neuropathic pain, autonomic nervous system dysfunction and strokes, but some rarer neurological manifestations exist. Among these, aseptic meningitis is a possible complication. Our objectives were to measure the prevalence of this complication in a cohort of patients with Fabry disease, and to describe its clinical features.

METHODS

We conducted a retrospective review of Fabry disease patients followed at our tertiary referral center between 1995 and September 2023 with at least one episode of meningitis, and performed a systematic review to identify similar published cases.

RESULTS

Four patients out of 107 (3.7%) had at least one episode of aseptic meningitis. Our systematic review identified 25 other observations. The median age of these 29 patients was 29.0 years, the median cerebrospinal fluid leukocyte count was 24 cells/mm3 with a predominance of lymphocytes in 64.7% of cases. In 82.8% of the patients, the diagnosis of Fabry disease was unknown before the meningitis. Large artery stenosis was present in 17.2% of patients and 57.1% of patients had a recent stroke concomitant with the meningitis. Several differential diagnoses were evoked, such as multiple sclerosis or central nervous system vasculitis.

INTERPRETATION

Our study suggests that Fabry disease should be considered as a cause of aseptic meningitis. The pathophysiological mechanisms underlying meningeal inflammation remain largely unknown but may reflect the dysregulation of pro-inflammatory signaling pathways.

Missed diagnosis of Fabry disease: should we screen patients with multiple sclerosis?

INTRODUCTION

Fabry disease (FD) can be undiagnosed in the context of multiple sclerosis (MS) due to similar clinical and paraclinical features. Our study aimed to determine the prevalence (and the necessity of screening) of FD among patients with possible or definite MS.

METHODS

In this prospective monocentric observational study, we included consecutive patients enrolled between May 2017 and May 2019 after the first clinical event suggestive of MS. All patients underwent FD screening using dried blood spots in a stepwise manner combining genetic and enzyme testing. Patients were followed until May 2022.

RESULTS

We included 160 patients (73.1% female, mean age 33.9 years). The 2017 revised McDonald's criteria for definite MS were fulfilled by 74 (46.3%) patients at the time of study recruitment and 89 (55.6%) patients after 3-5 years of follow-up. None of the patients had a pathogenic GLA variant, and four (2.5%) had a variant of unknown significance (p.A143T, p.S126G, 2 × p.D313Y). In two of these patients, the intrathecal synthesis of oligoclonal bands was absent, and none had hyperproteinorachia or pleocytosis in cerebrospinal fluid. Detailed examination of FD organ manifestations revealed only discrete ocular and kidney involvement in two patients.

CONCLUSION

The prevalence of FD in the population of suspected or definite MS patients does not appear to be high. Our results do not support routine FD screening in all patients with a possible diagnosis of MS, but there is an urgent need to search for red flags and include FD in the differential diagnosis of MS.

When and How to Diagnose Fabry Disease in Clinical Pratice

Fabry disease is a frequent lysosomal storage disorder secondary to the deficiency of alpha-galactosidase A enzyme. This X-linked genetic disease realizes progressive and systemic manifestations that affect both male and female. Fabry disease may present as "classical", as "late-onset" or "non-classical" forms. Symptoms and organ involvements of classical Fabry disease are acral pain crisis, cornea verticillata, hypertrophic cardiomyopathy, stroke and chronic kidney disease with proteinuria. Other common symptoms are often poorly recognized, such as gastrointestinal or ear involvements. In classical Fabry disease, symptoms first appear during childhood or during teenage years in males, but later in females. Patients with non-classical or late-onset Fabry disease have delayed manifestations or a single-organ involvement. Diagnosis is therefore difficult when classical organ involvements are missing, in paucisymptomatic patients or in late-onset forms. Recognition of Fabry disease is important because effective treatments are available. They have to be prescribed early. In male, diagnosis is made with alpha-galactosidase A enzyme activity dosage in leukocyte, that is very low or null in classical forms and under 30 percent in late-onset forms. Diagnosis is more challenging in females who may express normal residual enzyme activity. Other plasmatic biomarkers, such as lyso-globotriaosylceramide are interesting, especially in females. In this review, we aimed to summarize main clinical manifestations of Fabry disease to know when to evoke Fabry disease and propose a practical diagnosis algorithm to know how to diagnose.