Mastocytosis patients' cognitive dysfunctions correlate with the presence of spindle‐shaped mast cells in bone marrow

Mast cells in the autonomic nervous system and potential role in disorders with dysautonomia and neuroinflammation

Mast cells (MC) are ubiquitous in the body, and they are critical for not only in allergic diseases but also in immunity and inflammation, including having potential involvement in the pathophysiology of dysautonomias and neuroinflammatory disorders. MC are located perivascularly close to nerve endings and sites such as the carotid bodies, heart, hypothalamus, the pineal gland, and the adrenal gland that would allow them not only to regulate but also to be affected by the autonomic nervous system (ANS). MC are stimulated not only by allergens but also many other triggers including some from the ANS that can affect MC release of neurosensitizing, proinflammatory, and vasoactive mediators. Hence, MC may be able to regulate homeostatic functions that seem to be dysfunctional in many conditions, such as postural orthostatic tachycardia syndrome, autism spectrum disorder, myalgic encephalomyelitis/chronic fatigue syndrome, and Long-COVID syndrome. The evidence indicates that there is a possible association between these conditions and diseases associated with MC activation. There is no effective treatment for any form of these conditions other than minimizing symptoms. Given the many ways MC could be activated and the numerous mediators released, it would be important to develop ways to inhibit stimulation of MC and the release of ANS-relevant mediators.

Cognitive Impairment and Depression in Mastocytosis: A Synthesis of the Literature

PURPOSE OF REVIEW

Symptoms of depression and cognitive dysfunction are commonly reported in mastocytosis. The aims of this review paper are to summarize the current literature on cognitive dysfunction and depressive symptoms, elucidate some of the mechanistic pathways underlying depressive symptoms in mastocytosis, identify gaps in the literature, and offer guidance for future research in this area.

RECENT FINDINGS

The study of cognition and depression in mastocytosis is in its infancy and the methodological flaws of the current literature limit interpretability. There is preliminary evidence that some individuals with mastocytosis might experience mild deficits in memory. On average, depression symptom scores fell within the mild to moderate or sub-syndromal range. Regrettably, only one study utilized a standardized diagnostic instrument to assess major depressive disorder. The authors' tendency to inaccurately equate depressive symptoms with a diagnosis of major depressive disorder presents a notable issue. The prevalence of cognitive deficits and depression appears to be similar to other chronic illnesses. Future work needs to better characterize cognition and characterize "depression" in this population.

Cognitive, neuropsychiatric and neurological alterations in mastocytosis: A systematic review

BACKGROUND

Mastocytosis manifests with multisystemic symptoms, often involving the nervous system. Numerous cognitive, neuropsychiatric and neurological alterations have been reported in multiple observational studies.

METHODS

We performed a qualitative systematic literature review of reported data consulting the electronic databases Medline, Scopus, Web of Science, Cochrane, and BASE until June 2023.

RESULTS

We selected 24 studies in which the majority showed that a high proportion of mastocytosis patients suffer cognitive, neuropsychiatric and neurological alterations. The most common disorders and estimated ranges of frequency observed in adults were depression (68%-75%), anxiety, high stress or irritability (27%-54%), cognitive impairment (27%-39%, primarily affecting memory skills), and headaches (55%-69%). Attention challenges and learning difficulties were reported in children at a rate of 13%, while neurodevelopmental disorders occurred at rates of 8%-12%. Frequent white abnormalities in mastocytosis patients with concomitant psychocognitive symptoms have been reported although neuroimaging studies have been performed rarely in this population.

CONCLUSION

Further studies with more comprehensive and homogeneous evaluations and neuroimaging and histological analysis should be performed for a better understanding of these manifestations. An earlier detection and proper management of these symptoms could greatly improve the quality of life of these patients.