Rayan Najjar
@rna-guy.bsky.social
Physician scientist at UW rheumatology. I study the genome to search for the causes of autoimmune diseases. Creator of a podcast (Bitesize Immunology).
My research focuses on alternative splicing and non-coding RNA
🇮🇶🇺🇸
najjar.blog
My research focuses on alternative splicing and non-coding RNA
🇮🇶🇺🇸
najjar.blog
1/n
A dermatomyositis puzzle: it looks like a virus, but is not a virus, what is it?
A link with viruses has been explored for decades. This study looked for viral transcripts in RNAseq data of muscles from dermatomyositis patients, and found no viruses #rheumsky #immunosky #rnasky #medsky
A dermatomyositis puzzle: it looks like a virus, but is not a virus, what is it?
A link with viruses has been explored for decades. This study looked for viral transcripts in RNAseq data of muscles from dermatomyositis patients, and found no viruses #rheumsky #immunosky #rnasky #medsky
Deep RNA sequencing of muscle tissue reveals absence of viral signatures in dermatomyositis - PubMed
<span><b>Objective</b>: To explore a possible connection between active viral infections and manifestation of dermatomyositis (DM). <b>Methods:</b> Skeletal muscle biopsies were analyzed from patients...
pubmed.ncbi.nlm.nih.gov
September 5, 2025 at 4:25 AM
1/n
A dermatomyositis puzzle: it looks like a virus, but is not a virus, what is it?
A link with viruses has been explored for decades. This study looked for viral transcripts in RNAseq data of muscles from dermatomyositis patients, and found no viruses #rheumsky #immunosky #rnasky #medsky
A dermatomyositis puzzle: it looks like a virus, but is not a virus, what is it?
A link with viruses has been explored for decades. This study looked for viral transcripts in RNAseq data of muscles from dermatomyositis patients, and found no viruses #rheumsky #immunosky #rnasky #medsky
Biology is weird and complex
A common type of ant in Europe breaks a fundamental rule in biology: its queens can produce male offspring that are a whole different species
go.nature.com/4mOb5T9
go.nature.com/4mOb5T9
‘Almost unimaginable’: these ants are different species but share a mother
Ant queens of one species clone ants of another to create hybrid workers that do their bidding.
go.nature.com
September 3, 2025 at 10:17 PM
Biology is weird and complex
Happy international cat day! Did you know that your cat and all domestic cats, no matter where you are on Earth, are from the Middle East
www.science.org/doi/10.1126/...
www.science.org/doi/10.1126/...
The Near Eastern Origin of Cat Domestication
The world's domestic cats carry patterns of sequence variation in their genome that reflect a history of domestication and breed development. A genetic assessment of 979 domestic cats and their wild p...
www.science.org
August 9, 2025 at 3:05 AM
Happy international cat day! Did you know that your cat and all domestic cats, no matter where you are on Earth, are from the Middle East
www.science.org/doi/10.1126/...
www.science.org/doi/10.1126/...
A new discovery in dermatomyositis: We found a big increase in expression of Alu elements in dermatomyositis muscle + a signature of increased dsRNA. Read more about our findings and the hypothesis we propose in a paper recently accepted by A&R
#RheumSky #ImmunoSky #RNAsky
#RheumSky #ImmunoSky #RNAsky
Alu Overexpression Leads to an Increased Double‐stranded RNA Signature in Dermatomyositis
Objective
Dermatomyositis is an autoimmune condition characterized by a high interferon signature of unknown etiology. Because coding sequences constitute <1.2% of our genomes, there is a need to ex.....
acrjournals.onlinelibrary.wiley.com
August 2, 2025 at 2:13 PM
A new discovery in dermatomyositis: We found a big increase in expression of Alu elements in dermatomyositis muscle + a signature of increased dsRNA. Read more about our findings and the hypothesis we propose in a paper recently accepted by A&R
#RheumSky #ImmunoSky #RNAsky
#RheumSky #ImmunoSky #RNAsky
Being a scientist is like being a standup comedian, you generate jokes (data) until you have enough material for a 1-hour event, then you tour the country to perform shows (grand rounds)
#academicsky
#academicsky
June 6, 2025 at 12:50 AM
Being a scientist is like being a standup comedian, you generate jokes (data) until you have enough material for a 1-hour event, then you tour the country to perform shows (grand rounds)
#academicsky
#academicsky
Reposted by Rayan Najjar
My quote of the day
If an elderly but distinguished scientist says that something is possible, he is almost certainly right; but if he says that it is impossible, he is very probably wrong.
Arthur C. Clarke
If an elderly but distinguished scientist says that something is possible, he is almost certainly right; but if he says that it is impossible, he is very probably wrong.
Arthur C. Clarke
June 1, 2025 at 1:05 PM
My quote of the day
If an elderly but distinguished scientist says that something is possible, he is almost certainly right; but if he says that it is impossible, he is very probably wrong.
Arthur C. Clarke
If an elderly but distinguished scientist says that something is possible, he is almost certainly right; but if he says that it is impossible, he is very probably wrong.
Arthur C. Clarke
Reporting of the Xenon gas Mount Everest story makes it seem like anyone can just take Xenon and climb a mountain. These men were highly trained and spent 10 weeks sleeping in low oxygen tents, so they did acclimatize. It is unknown how much additional benefit Xenon provided (no control group)
Climbers use controversial xenon gas to climb Everest
YouTube video by NBC News
youtu.be
June 2, 2025 at 2:29 AM
Reporting of the Xenon gas Mount Everest story makes it seem like anyone can just take Xenon and climb a mountain. These men were highly trained and spent 10 weeks sleeping in low oxygen tents, so they did acclimatize. It is unknown how much additional benefit Xenon provided (no control group)
First time at the #RNA25 conference. I’m delighted to overhear nearby groups say the word RNA so many times. The control frequency is zero
May 28, 2025 at 11:23 PM
First time at the #RNA25 conference. I’m delighted to overhear nearby groups say the word RNA so many times. The control frequency is zero
Phrases in immunology that mean "we do not know":
- loss of tolerance
- crosstalk
- caused by genetic and environmental factors
#ImmunoSky #MedSky
- loss of tolerance
- crosstalk
- caused by genetic and environmental factors
#ImmunoSky #MedSky
May 25, 2025 at 5:03 PM
Phrases in immunology that mean "we do not know":
- loss of tolerance
- crosstalk
- caused by genetic and environmental factors
#ImmunoSky #MedSky
- loss of tolerance
- crosstalk
- caused by genetic and environmental factors
#ImmunoSky #MedSky
New podcast episode on inflammation. topics covered:
- Inflammation is good for you
- Why and how do we develop fever? I question the idea that fever boosts immune processes or hurts pathogens.
- Low level non-infectious chronic inflammation
#ImmunoSky #MedSky
- Inflammation is good for you
- Why and how do we develop fever? I question the idea that fever boosts immune processes or hurts pathogens.
- Low level non-infectious chronic inflammation
#ImmunoSky #MedSky
What is inflammation?
Listen on Apple Podcasts Listen on Spotify Welcome to bitesize immunology, I’m your host Dr Rayan Najjar, a physician scientist in rheumatology. Inflammation is a reaction from the immune system to…
najjar.blog
May 10, 2025 at 11:19 PM
New podcast episode on inflammation. topics covered:
- Inflammation is good for you
- Why and how do we develop fever? I question the idea that fever boosts immune processes or hurts pathogens.
- Low level non-infectious chronic inflammation
#ImmunoSky #MedSky
- Inflammation is good for you
- Why and how do we develop fever? I question the idea that fever boosts immune processes or hurts pathogens.
- Low level non-infectious chronic inflammation
#ImmunoSky #MedSky
1/2
A new publication with a new idea in autoimmunity.
- The immune system learns to tolerate normally expressed peptides. This includes the multiple transcripts of the same genes that are made through alternative splicing.
#MedSky #ImmunoSky #RheumSky
A new publication with a new idea in autoimmunity.
- The immune system learns to tolerate normally expressed peptides. This includes the multiple transcripts of the same genes that are made through alternative splicing.
#MedSky #ImmunoSky #RheumSky
Altered Protein Structures and Neoepitopes in Lupus Neutrophils From Dysregulated Splicing of Messenger RNA
Objective
To test whether messenger RNA (mRNA) splicing is altered in neutrophils from patients with systemic lupus erythematosus (SLE) and can produce neoantigens.
Methods
RNA sequencing of neutr.....
acrjournals.onlinelibrary.wiley.com
April 7, 2025 at 12:20 AM
1/2
A new publication with a new idea in autoimmunity.
- The immune system learns to tolerate normally expressed peptides. This includes the multiple transcripts of the same genes that are made through alternative splicing.
#MedSky #ImmunoSky #RheumSky
A new publication with a new idea in autoimmunity.
- The immune system learns to tolerate normally expressed peptides. This includes the multiple transcripts of the same genes that are made through alternative splicing.
#MedSky #ImmunoSky #RheumSky
Reposted by Rayan Najjar
Weekly recap in ACR Journals
Environmental Risk Factors for SLE through the Lens of Social Determinants of Health
doi.org/10.1002/acr....
Dysregulated mRNA splicing in SLE
doi.org/10.1002/acr2...
Associations of fire smoke and other pollutants with incident RA and RA-ILD
doi.org/10.1002/art....
Environmental Risk Factors for SLE through the Lens of Social Determinants of Health
doi.org/10.1002/acr....
Dysregulated mRNA splicing in SLE
doi.org/10.1002/acr2...
Associations of fire smoke and other pollutants with incident RA and RA-ILD
doi.org/10.1002/art....
January 18, 2025 at 1:35 PM
Weekly recap in ACR Journals
Environmental Risk Factors for SLE through the Lens of Social Determinants of Health
doi.org/10.1002/acr....
Dysregulated mRNA splicing in SLE
doi.org/10.1002/acr2...
Associations of fire smoke and other pollutants with incident RA and RA-ILD
doi.org/10.1002/art....
Environmental Risk Factors for SLE through the Lens of Social Determinants of Health
doi.org/10.1002/acr....
Dysregulated mRNA splicing in SLE
doi.org/10.1002/acr2...
Associations of fire smoke and other pollutants with incident RA and RA-ILD
doi.org/10.1002/art....
I haven't done long exposure photography in years, decided to try it again on NYE. The space needle was electrified with fireworks and drones. Happy New Year #seattle
January 4, 2025 at 10:20 PM
I haven't done long exposure photography in years, decided to try it again on NYE. The space needle was electrified with fireworks and drones. Happy New Year #seattle
1/2
What do you think of these jobs I assigned to T cells?
CTL= a bounty hunter with a wanted poster (TCR)
Th1= a personal trainer pushing macrophages to do better
Th2= a plumber flushing intestinal pipes, who also has anxiety
Th17= a lobbyist asking for more neutrophils
#MedSky #ImmunoSky #RheumSky
What do you think of these jobs I assigned to T cells?
CTL= a bounty hunter with a wanted poster (TCR)
Th1= a personal trainer pushing macrophages to do better
Th2= a plumber flushing intestinal pipes, who also has anxiety
Th17= a lobbyist asking for more neutrophils
#MedSky #ImmunoSky #RheumSky
December 5, 2024 at 5:03 AM
1/2
What do you think of these jobs I assigned to T cells?
CTL= a bounty hunter with a wanted poster (TCR)
Th1= a personal trainer pushing macrophages to do better
Th2= a plumber flushing intestinal pipes, who also has anxiety
Th17= a lobbyist asking for more neutrophils
#MedSky #ImmunoSky #RheumSky
What do you think of these jobs I assigned to T cells?
CTL= a bounty hunter with a wanted poster (TCR)
Th1= a personal trainer pushing macrophages to do better
Th2= a plumber flushing intestinal pipes, who also has anxiety
Th17= a lobbyist asking for more neutrophils
#MedSky #ImmunoSky #RheumSky
It's day 7 of your Covid-19 infection: Each T cell that recognized the virus was activated and has been copying itself over and over again until a clone army is created. Listen to my latest podcast on T cells najjar.blog/2024/12/01/what-are-t-cells/
#ImmunoSky #MedSky
#ImmunoSky #MedSky
December 4, 2024 at 3:33 AM
It's day 7 of your Covid-19 infection: Each T cell that recognized the virus was activated and has been copying itself over and over again until a clone army is created. Listen to my latest podcast on T cells najjar.blog/2024/12/01/what-are-t-cells/
#ImmunoSky #MedSky
#ImmunoSky #MedSky
1/2
A Sisyphean T cell: One of your T cells recognizes a virus that does not infect humans. It will circulate endlessly between lymph nodes, touching countless dendritic cells but never finding its antigen. Listen to my latest podcast episode on T cells najjar.blog/2024/12/01/what-are-t-cells/
A Sisyphean T cell: One of your T cells recognizes a virus that does not infect humans. It will circulate endlessly between lymph nodes, touching countless dendritic cells but never finding its antigen. Listen to my latest podcast episode on T cells najjar.blog/2024/12/01/what-are-t-cells/
December 1, 2024 at 10:15 PM
1/2
A Sisyphean T cell: One of your T cells recognizes a virus that does not infect humans. It will circulate endlessly between lymph nodes, touching countless dendritic cells but never finding its antigen. Listen to my latest podcast episode on T cells najjar.blog/2024/12/01/what-are-t-cells/
A Sisyphean T cell: One of your T cells recognizes a virus that does not infect humans. It will circulate endlessly between lymph nodes, touching countless dendritic cells but never finding its antigen. Listen to my latest podcast episode on T cells najjar.blog/2024/12/01/what-are-t-cells/
Reposted by Rayan Najjar
Viral persistence is a complex phenomenon observed in several viruses, particularly those from the herpes family. These viruses can enter a latent state, evading detection by the innate immune system through mechanisms that aren't fully understood.
November 30, 2024 at 9:43 PM
Viral persistence is a complex phenomenon observed in several viruses, particularly those from the herpes family. These viruses can enter a latent state, evading detection by the innate immune system through mechanisms that aren't fully understood.
Which statement is more correct?
1. Lupus is one disease. One day we will have highly effective treatments that work for most patients
2. Lupus is a phenotypic grouping of multiple diseases. One day we will have highly effective treatments that each work for a subset of patients #medsky #rheumsky
1. Lupus is one disease. One day we will have highly effective treatments that work for most patients
2. Lupus is a phenotypic grouping of multiple diseases. One day we will have highly effective treatments that each work for a subset of patients #medsky #rheumsky
November 26, 2024 at 5:05 AM
Reposted by Rayan Najjar
Hi all 👋 I am new to this, but was convinced to join by @rna-guy.bsky.social for the #medsky #rheumsky of it all during #ACR2024! I am a clinician-scholar bringing a sociological structural critical lens to rheumatology especially around issues of race, gender, immigration and class. Let's connect!
November 19, 2024 at 2:40 AM
Hi all 👋 I am new to this, but was convinced to join by @rna-guy.bsky.social for the #medsky #rheumsky of it all during #ACR2024! I am a clinician-scholar bringing a sociological structural critical lens to rheumatology especially around issues of race, gender, immigration and class. Let's connect!
I'm proud to share an original bad joke that I came up with:
- What's your favorite snack?
- RNA scientist: GUAC
Where are my fellow RNA scientists #RNAsky #rnabiology
- What's your favorite snack?
- RNA scientist: GUAC
Where are my fellow RNA scientists #RNAsky #rnabiology
November 13, 2024 at 5:31 AM
I'm proud to share an original bad joke that I came up with:
- What's your favorite snack?
- RNA scientist: GUAC
Where are my fellow RNA scientists #RNAsky #rnabiology
- What's your favorite snack?
- RNA scientist: GUAC
Where are my fellow RNA scientists #RNAsky #rnabiology
Reposted by Rayan Najjar
Added new folks to the #Immunology Starter Pack 🧪
@sarahdimeloe.bsky.social
@mahimaswamy.bsky.social
@profken.bsky.social
@johannajoyce.bsky.social
@alanmcn1.bsky.social
@immunoah.bsky.social
@bnmelgert.bsky.social
@copperbae.bsky.social
@benjaminkrishn3.bsky.social
go.bsky.app/PY5tCas
@sarahdimeloe.bsky.social
@mahimaswamy.bsky.social
@profken.bsky.social
@johannajoyce.bsky.social
@alanmcn1.bsky.social
@immunoah.bsky.social
@bnmelgert.bsky.social
@copperbae.bsky.social
@benjaminkrishn3.bsky.social
go.bsky.app/PY5tCas
October 28, 2024 at 7:37 PM
A naive B cell receives a vision from an oracle (T follicular helper cell), it now knows its destiny is not to fight infection. Instead, its fate is to be auto-reactive creating an autoimmune disease (myasthenia gravis), but first it must survive the negative selection #ImmunoSky #MedSky #RheumSky
November 12, 2024 at 1:26 AM
A naive B cell receives a vision from an oracle (T follicular helper cell), it now knows its destiny is not to fight infection. Instead, its fate is to be auto-reactive creating an autoimmune disease (myasthenia gravis), but first it must survive the negative selection #ImmunoSky #MedSky #RheumSky
I'm working on a podcast episode on types of T cells, I try to imagine different jobs or roles for each type, to make learning more fun. I imagined the T follicular helper cell as an oracle that appears in visions to B cells to tell them their destiny #ImmunoSky #RheumSky #MedSky
November 10, 2024 at 1:12 AM
I'm working on a podcast episode on types of T cells, I try to imagine different jobs or roles for each type, to make learning more fun. I imagined the T follicular helper cell as an oracle that appears in visions to B cells to tell them their destiny #ImmunoSky #RheumSky #MedSky
Reposted by Rayan Najjar
Looking to gather a list of all rheumatologists and rheumatology professionals!
Comment if I missed you!
#ACR24
#rheum
go.bsky.app/CEj2dcZ
Comment if I missed you!
#ACR24
#rheum
go.bsky.app/CEj2dcZ
November 7, 2024 at 5:50 PM
Looking to gather a list of all rheumatologists and rheumatology professionals!
Comment if I missed you!
#ACR24
#rheum
go.bsky.app/CEj2dcZ
Comment if I missed you!
#ACR24
#rheum
go.bsky.app/CEj2dcZ
1/3 Autoimmunity remains a mystery. I'm happy to share a preprint reporting a discovery that may shed light on the pathogenesis of dermatomyositis
#immunoSky #medSky
www.medrxiv.org/content/10.1...
#immunoSky #medSky
www.medrxiv.org/content/10.1...
Alu overexpression leads to increased double-stranded RNA in dermatomyositis
Dermatomyositis is an autoimmune condition characterized by a high interferon signature of unknown etiology. Because genes constitute only <2% of our genomes, there is a need to explore the role of th...
www.medrxiv.org
November 5, 2024 at 7:07 AM
1/3 Autoimmunity remains a mystery. I'm happy to share a preprint reporting a discovery that may shed light on the pathogenesis of dermatomyositis
#immunoSky #medSky
www.medrxiv.org/content/10.1...
#immunoSky #medSky
www.medrxiv.org/content/10.1...