#Mast Cells

[bpod-bpod]

No Turning Back

Neutrophils (often referred to as polymorphs) – a kind of white blood cell that are the immune system's first responders – are attracted by, trapped and die inside another type of white blood cell called mast cells that are at the heart of an allergic response, adding to the state of chronic allergic inflammation. Neutrophils are seen here in cyan trapped inside mast cells in yellow

Read the published research article here

Image from work by Michael Mihlan and colleagues

Max Planck Institute of Immunobiology and Epigenetics, Freiburg, Germany

Image originally published with a Creative Commons Attribution 4.0 International (CC BY 4.0)

Published in Cell, August 2024

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[whatshouldwecallchronicillness]

When they get my order wrong and I can’t eat it...

[willowreader]

I had a Mast Cell reaction after a Covid Infection. This is a good article about Mast Cells and their function.

[didanawisgi]

Quercetin Is More Effective than Cromolyn in Blocking Human Mast Cell Cytokine Release and Inhibits Contact Dermatitis and Photosensitivity in Humans

[notquite-docbirdy]

Image 1: Cancerous changes in cells from a mass on the toe. Near the center is an actively dividing cell, you can also see that the cells have nuclei of variable sizes, and a few multinucleate cells. We suspect it is a mast cell due to the findings in image 2.

Image 2: Mass on the left chest that has been growing and shrinking for the last 6 months. Microscopic findings show a field of granules consistent with mast cells, though no mast cells were seen. Not included in this image were cancerous changes of the cells.

Ultrasound of the spleen was inconclusive (mast cells can sometimes have splenic involvement). Owner is electing for surgical removal of both masses.

[homeostasister]

A Th2 Anthem

We will bring the floods, the pain and the violence

We’ll summon the soldiers of russet and violet

To sound the sirens and slay the giant

And when the battle is over, in the damage we’ve wrought

We’ll call upon the sentinels

To stay the weather and build back better

[chronicallydragons]

anyone else ever wish they could lie down harder? Like, I'm already horizontal, but I need more horizontal. I need to be absorbed by the floor. I think that would fix me

[longhaulerbear]

From 2022:

Mast cells (MCs) are the major effector cells of allergic responses and reside throughout the body, including in the brain and meninges. Previously, we showed in a mouse model of subclinical cow’s milk allergy that brain MC numbers were elevated in sensitized mice. However, the neurophysiological consequences of intracranial MC accumulation and activation are unclear. We hypothesized that centrally recruited MCs in sensitized mice could be activated by the allergen via the IgE/FcεRI mechanism and increase the blood–brain barrier (BBB) permeability to promote neuroinflammation. Furthermore, we suspected that repeated allergen exposure could sustain MC activation. To investigate our hypothesis, we sensitized C57BL6/J mice to a bovine whey allergen, β-lactoglobulin (BLG), and subsequently placed them on a whey-containing diet for two weeks. MC activity and associated changes in the brain were examined. BLG-sensitized mice showed mobility changes and depression-like behavior with significantly increased MC numbers and histamine levels in select brain regions. IgG extravasation and perivascular astrogliosis were also evident. Importantly, myelin staining revealed cortical demyelination in the BLG-sensitized mice, suggesting a potential neural substrate for their behavioral changes. Our findings support the ability of brain MCs to release histamine and other mediators to increase BBB permeability and facilitate neuroinflammatory responses in the brain.

MCs are also present in the central nervous system (CNS), including the brain parenchyma, choroid plexus, and meninges.

The number of MCs rises after traumatic brain injuries or ischemic events, increasing BBB permeability to facilitate peripheral leukocyte influx and sustain the inflammatory state

Our observations suggested that allergy-induced peripheral inflammation could result in the activation of central MCs and behavioral changes, at least in male mice. However, how intracranial MCs are stimulated in sensitized mice, how degranulated MCs influence brain function, and whether meningeal MCs are also invloved remains to be elucidated.

There has been growing interest in the contribution of MCs to neuroinflammation and pathophysiology associated with neuropsychiatric and neurodegenerative disorders. However, the specific role of MCs in the development of these conditions has yet to be clarified. As a step toward understanding their involvement, we investigated intracranial MCs and associated neuropathologies in a mouse model of CMA, particularly when mice continued to be challenged repeatedly with the allergen.

Since chronic inflammation is associated with various disease conditions [64,65,66,67,68], understanding the long-term consequences of immune activation is important for individuals with chronic immune disorders, such as allergies. Although female mice did not seem to be significantly affected by allergen sensitization and acute challenge in our previous studies [47,48], it is of our interest to include this experimental group and investigate whether prolonged allergen exposure would elicit delayed effects in females as distinct immunological and neurological phenotypes.

Thus, it is plausible that intracranial MCs in the CMA mice can be activated by allergens, particularly if the allergen has an ample opportunity to infiltrate intestines with repeated allergen consumption. Indeed, BLG was detected in the sera and the brain of the sensitized mice (Figure 9A,B), strengthening this possibility. However, regional differences in the levels of BLG were notable in the brain, with the midbrain region having a significantly greater amount of BLG than in the sham mice. The midbrain is a highly vascularized region, with the convergence of the major cerebral arteries, including the basilar, posterior cerebral, posterior communicating, and superior cerebellar arteries, supplying the region [75,76]. Therefore, the midbrain region may serve as an access point into the brain from circulation, and MCs in this region likely encounter BLG.

The brain’s histaminergic system controls a variety of behaviors, including sleep–wake cycles, satiety, mobility, emotion, and memory (reviewed in [78]). The effects of histamine are mediated through four histamine receptor subtypes, H1–H4 receptors. Previously, we reported that greater H3R immunoreactivity was detected in the cortical region of whey protein-sensitized mice with acute allergen challenge, although brain histamine levels were not quantified in these mice [46]. In the present study, we found that H3R levels showed an increasing trend in the frontal cortex and significant elevation in the parietotemporal cortex, suggesting that the greater amounts of histamine found in these regions might have influenced the expression of the receptor. Since H3R functions as a presynaptic autoreceptor to regulate the activity of histaminergic neurons [79], regional increases in histamine concentration could have altered the receptor expression.

The causative role of MCs in CMA-associated cortical demyelination warrants further investigation as the involvement of MCs in multiple sclerosis, a demyelinating disease, has become increasingly evident [77,82,83]. It would also be of future interest to determine whether the demyelination in BLG-sensitized mice is reversible upon discontinuation of allergen consumption.

[medicomunicare]

Limb osteoarthritis: while pain exploits mastcells to make "kneel", talarozole could be a new remedy "at hand"

Limb osteoarthritis: while pain exploits mastcells to make “kneel”, talarozole could be a new remedy “at hand”

More than 40% of individuals will develop osteoarthritis (OA) during their lifetime. Hand osteoarthritis is a common and debilitating medical condition that affects mainly women, especially around the time of the menopause. Despite often being dismissed as just a few aches and pains, OA can have a profound and far-reaching impact on life, affecting people’s ability to work, care for a family, or…

[thebibliosphere]

For all the progress I've made with my health (and I've made a lot), it's still one of the most annoying features of my MCAS that stress--or basically any too strong an emotion-- can trigger an anaphylactic reaction.

On the one hand, it's forced me to do so much therapy to get a hold of my emotional dysregulation and trauma, and that's a good thing. That's good for my emotional wellbeing.

But it's also a bandaid to the fact that my immune system is so broken it throws my entire body into fight or flight mode at the least provocation, and instead of choosing either fight, flight, or fawn, it goes for the secret fourth option which is to set fire to the house (me) and swell my throat shut.

Like that is the opposite of a survival instinct.

That is my body sensing the tiger in the tall grass, and going, "No, thank you," and noping the fuck out before the tiger can even get to it.

[98lindsey]

I was out with my family for my birthday at a restaurant when I started having an allergic reaction. So I pulled out my IV stuff to give myself something to stop it and my dad asks:

“Do you want to go in the bathroom and do that”

I laughed a little “um, not really”

I understand it’s a little strange for me to pull out needles and meds and everything in public, but the restaurant bathroom is the last place I want to be when setting up something to inject into my blood stream 😬

Can we normalize people having to regulate their bodies with medication in public please?

[willowreader]

People wonder how #LongCovid could possibly cause 200+ symptoms throughout the body, head to toe...

"Mast cells are immune cells distributed throughout nearly all tissues, mostly in skin, near blood vessels & lymph vessels, nerves, in lungs & intestines.

[thatchronicfeeling]

Medical Person: What are your symptoms? Disabled/Chronically Ill Person: This is a trap.

[stagegoose]

shout out to those of us chronically ill people who have stacks of rare diagnoses that took years or decades to dx. Shout out. to those of us in those categories who had earlier diagnoses questioned because of our other, at this point undiagnosed, rare illnesses.

To have a doctor look at something very concrete and telling of a certain diagnosis (for me, it was a muscle biopsy that showed a very obvious mitochondrial cytopathy) and go 'nah i don't think its actually this thing we have evidence of' because you also have another completely unrelated rare illness is gross and inexcusable.

If you are in this situation, i pray that things prevail for you. Remember that you know your body far better than any medical professional ever will, and that no matter what they say, you're not crazy for having inexplicable symptoms.

to deny the idea that someone can be doubly sick with three or more different rare illnesses when we know so little about genetics and all the different ways the human body can screw itself over is extremely and without a doubt idiotic. we all deserve better.

[gabessquishytum]

As a disabled/chronic illness person you're legally allowed to assign disabilities and chronic illnesses to any fictional character. In case you were wondering.