Haptoglobin Phenotypes Stratify Post-Exertional Cognitive Dysfunction Associated with Altered Cerebral Oxygenation and Metabolic Signatures in Long COVID
A.Moezzi, A. Moreau et al. (2026)
#Haptoglobin #PEM #CBF #LongCOVID
A.Moezzi, A. Moreau et al. (2026)
#Haptoglobin #PEM #CBF #LongCOVID
www.mdpi.com
September 24, 2026 at 3:51 PM
Haptoglobin Phenotypes Stratify Post-Exertional Cognitive Dysfunction Associated with Altered Cerebral Oxygenation and Metabolic Signatures in Long COVID
A.Moezzi, A. Moreau et al. (2026)
#Haptoglobin #PEM #CBF #LongCOVID
A.Moezzi, A. Moreau et al. (2026)
#Haptoglobin #PEM #CBF #LongCOVID
Role of haptoglobin and its phenotypic variations in the pathophysiology of myalgic encephalomyelitis and long COVID — Moezzi PhD thesis.
umontreal.scholaris.ca/items/f5770e...
#MEcfs #LongCovid #CFS #PwME
umontreal.scholaris.ca/items/f5770e...
#MEcfs #LongCovid #CFS #PwME
Role of haptoglobin and its phenotypic variations in the pathophysiology of myalgic encephalomyelitis and long COVID
L’encéphalomyélite myalgique (EM) et le COVID Long (LC) sont des maladies chroniques multi-systémiques caractérisées par un le malaise post-effort (post-exertional malaise en anglais ou PEM), des trou...
umontreal.scholaris.ca
September 28, 2026 at 1:03 AM
Role of haptoglobin and its phenotypic variations in the pathophysiology of myalgic encephalomyelitis and long COVID — Moezzi PhD thesis.
umontreal.scholaris.ca/items/f5770e...
#MEcfs #LongCovid #CFS #PwME
umontreal.scholaris.ca/items/f5770e...
#MEcfs #LongCovid #CFS #PwME
Role of haptoglobin and its phenotypic variations in the pathophysiology of myalgic encephalomyelitis and long COVID — Moezzi
PhD thesis.
#MECFS
PhD thesis.
#MECFS
Article Link
umontreal.scholaris.ca
September 28, 2026 at 8:17 PM
Role of haptoglobin and its phenotypic variations in the pathophysiology of myalgic encephalomyelitis and long COVID — Moezzi
PhD thesis.
#MECFS
PhD thesis.
#MECFS
Manchmal gehen rote Blutkörperchen kaputt. Das nennt man hämolytische Anämie. Dafür gibt es spezielle Labormarker (Haptoglobin).
Wenn Blut über den Magen-Darm-Trakt verloren geht, wird der Stuhlgang häufig dunkel bis schwarz.
Bakterien im Dickdarm bauen dabei das Blut ab.
⬇️
Wenn Blut über den Magen-Darm-Trakt verloren geht, wird der Stuhlgang häufig dunkel bis schwarz.
Bakterien im Dickdarm bauen dabei das Blut ab.
⬇️
July 25, 2025 at 1:38 PM
Manchmal gehen rote Blutkörperchen kaputt. Das nennt man hämolytische Anämie. Dafür gibt es spezielle Labormarker (Haptoglobin).
Wenn Blut über den Magen-Darm-Trakt verloren geht, wird der Stuhlgang häufig dunkel bis schwarz.
Bakterien im Dickdarm bauen dabei das Blut ab.
⬇️
Wenn Blut über den Magen-Darm-Trakt verloren geht, wird der Stuhlgang häufig dunkel bis schwarz.
Bakterien im Dickdarm bauen dabei das Blut ab.
⬇️
I couldn’t remember all the causes for an *increased* haptoglobin so I turned to our trusty Google search which has AI Overview turned on by default and which helpfully highlighted a scenario where haptoglobin is known to be *decreased* but nonetheless said it would be *increased*.
October 17, 2024 at 2:19 PM
I couldn’t remember all the causes for an *increased* haptoglobin so I turned to our trusty Google search which has AI Overview turned on by default and which helpfully highlighted a scenario where haptoglobin is known to be *decreased* but nonetheless said it would be *increased*.
OMF Collaboration Investigates Molecular Basis of Post-Exertional Malaise (PEM) 👉 Read more from Dr. Moreau: www.omf.ngo/haptoglobin-....
Key findings:
➡️ After a mild stress challenge, #pwME showed a sharp drop in haptoglobin (Hp) levels, while healthy controls did not. (1/2)
Key findings:
➡️ After a mild stress challenge, #pwME showed a sharp drop in haptoglobin (Hp) levels, while healthy controls did not. (1/2)
New Publication from OMF Collaboration Investigates Molecular Basis of PEM - Open Medicine Foundation
New publication reveals first strong evidence of a genetic contribution to post-exertional malaise (PEM) in ME/CFS.
www.omf.ngo
September 16, 2025 at 4:45 PM
OMF Collaboration Investigates Molecular Basis of Post-Exertional Malaise (PEM) 👉 Read more from Dr. Moreau: www.omf.ngo/haptoglobin-....
Key findings:
➡️ After a mild stress challenge, #pwME showed a sharp drop in haptoglobin (Hp) levels, while healthy controls did not. (1/2)
Key findings:
➡️ After a mild stress challenge, #pwME showed a sharp drop in haptoglobin (Hp) levels, while healthy controls did not. (1/2)
#Hidradenitis suppurativa (acne inversa) is linked to #diabetes mellitus. In the affected, #SPINA-GR is reduced and not compensated by #SPINA-GBeta, resulting in low #SPINA-DI. This phenomenon may be mediated by #inflammation, as shown by ties to #haptoglobin.
pubmed.ncbi.nlm.nih.gov/40217596/
pubmed.ncbi.nlm.nih.gov/40217596/
April 13, 2025 at 3:26 PM
#Hidradenitis suppurativa (acne inversa) is linked to #diabetes mellitus. In the affected, #SPINA-GR is reduced and not compensated by #SPINA-GBeta, resulting in low #SPINA-DI. This phenomenon may be mediated by #inflammation, as shown by ties to #haptoglobin.
pubmed.ncbi.nlm.nih.gov/40217596/
pubmed.ncbi.nlm.nih.gov/40217596/
Overall, the study identifies haptoglobin phenotype as a promising biomarker capable of stratifying #LongCovid patients into biologically distinct subgroups.
Read Paper: www.mdpi.com/1422-0067/27... 4/
Read Paper: www.mdpi.com/1422-0067/27... 4/
www.mdpi.com
August 17, 2026 at 6:34 PM
Overall, the study identifies haptoglobin phenotype as a promising biomarker capable of stratifying #LongCovid patients into biologically distinct subgroups.
Read Paper: www.mdpi.com/1422-0067/27... 4/
Read Paper: www.mdpi.com/1422-0067/27... 4/
1) 🇨🇦 In a new ME/CFS study, the research team of Alain Moreau reports that haptoglobin (Hp) might be a potential biomarker of PEM severity and cognitive impairment.
Its main function is to bind free hemoglobin that is released after the breakdown of red blood cells.
Its main function is to bind free hemoglobin that is released after the breakdown of red blood cells.
August 30, 2025 at 11:42 AM
1) 🇨🇦 In a new ME/CFS study, the research team of Alain Moreau reports that haptoglobin (Hp) might be a potential biomarker of PEM severity and cognitive impairment.
Its main function is to bind free hemoglobin that is released after the breakdown of red blood cells.
Its main function is to bind free hemoglobin that is released after the breakdown of red blood cells.
5) Next, they found differences in the phenotype distribution of the haptoglobin gene.
Fewer ME/CFS patients had the Hp1-1 phenotype compared to controls (ca. 10% versus 20%). HP-1 is considered the more efficient form of haptoglobin at binding free hemoglobin.
Fewer ME/CFS patients had the Hp1-1 phenotype compared to controls (ca. 10% versus 20%). HP-1 is considered the more efficient form of haptoglobin at binding free hemoglobin.
August 30, 2025 at 11:42 AM
5) Next, they found differences in the phenotype distribution of the haptoglobin gene.
Fewer ME/CFS patients had the Hp1-1 phenotype compared to controls (ca. 10% versus 20%). HP-1 is considered the more efficient form of haptoglobin at binding free hemoglobin.
Fewer ME/CFS patients had the Hp1-1 phenotype compared to controls (ca. 10% versus 20%). HP-1 is considered the more efficient form of haptoglobin at binding free hemoglobin.
Haptoglobin phenotypes and structural variants associate with post-exertional malaise and cognitive dysfunction in myalgic encephalomyelitis A. Moreau et al. (2025)
#ME/CFS #Haptoglobin #PEM
#ME/CFS #Haptoglobin #PEM
Haptoglobin phenotypes and structural variants associate with post-exertional malaise and cognitive dysfunction in myalgic encephalomyelitis - Journal of Translational Medicine
Background Myalgic encephalomyelitis (ME) is a chronic, multisystem illness characterized by post-exertional malaise (PEM) and cognitive dysfunction, yet the molecular mechanisms driving these hallmar...
link.springer.com
September 24, 2026 at 3:48 PM
Haptoglobin phenotypes and structural variants associate with post-exertional malaise and cognitive dysfunction in myalgic encephalomyelitis A. Moreau et al. (2025)
#ME/CFS #Haptoglobin #PEM
#ME/CFS #Haptoglobin #PEM
Haptoglobin Types Linked to Post-Exertional Brain Decline in Long COVID
www.thailandmedical.news/news/haptogl...
www.thailandmedical.news/news/haptogl...
Haptoglobin Types Linked to Post-Exertional Brain Decline in Long COVID - Thailand Medical News
www.thailandmedical.news
August 5, 2026 at 1:53 AM
Haptoglobin Types Linked to Post-Exertional Brain Decline in Long COVID
www.thailandmedical.news/news/haptogl...
www.thailandmedical.news/news/haptogl...
not a fan of haptoglobin, I see.
October 14, 2025 at 7:50 AM
not a fan of haptoglobin, I see.
A new PLRC-funded study is out from Dr. Moreau & team!
They studied whether inherited haptoglobin phenotypes—a genetic trait that determines how efficiently the body clears free hemoglobin & protects tissues from oxidative stress—could explain part of the variability of severity in #LongCovid 1/
They studied whether inherited haptoglobin phenotypes—a genetic trait that determines how efficiently the body clears free hemoglobin & protects tissues from oxidative stress—could explain part of the variability of severity in #LongCovid 1/
www.mdpi.com
August 17, 2026 at 6:34 PM
A new PLRC-funded study is out from Dr. Moreau & team!
They studied whether inherited haptoglobin phenotypes—a genetic trait that determines how efficiently the body clears free hemoglobin & protects tissues from oxidative stress—could explain part of the variability of severity in #LongCovid 1/
They studied whether inherited haptoglobin phenotypes—a genetic trait that determines how efficiently the body clears free hemoglobin & protects tissues from oxidative stress—could explain part of the variability of severity in #LongCovid 1/
From Canada:
Haptoglobin phenotypes and structural variants associate with post-exertional malaise and cognitive dysfunction in myalgic encephalomyelitis
translational-medicine.biomedcentral.com/articles/10....
Screenshot from latest Science for ME weekly update
#MEcfs #PwME
Haptoglobin phenotypes and structural variants associate with post-exertional malaise and cognitive dysfunction in myalgic encephalomyelitis
translational-medicine.biomedcentral.com/articles/10....
Screenshot from latest Science for ME weekly update
#MEcfs #PwME
September 2, 2025 at 12:48 AM
From Canada:
Haptoglobin phenotypes and structural variants associate with post-exertional malaise and cognitive dysfunction in myalgic encephalomyelitis
translational-medicine.biomedcentral.com/articles/10....
Screenshot from latest Science for ME weekly update
#MEcfs #PwME
Haptoglobin phenotypes and structural variants associate with post-exertional malaise and cognitive dysfunction in myalgic encephalomyelitis
translational-medicine.biomedcentral.com/articles/10....
Screenshot from latest Science for ME weekly update
#MEcfs #PwME
From ME Research UK @meresearchuk.bsky.social
A study has found that haptoglobin – a protein that plays a crucial role in recycling iron and protecting the body from the harm caused during oxidative stress – may be linked to post exertional malaise.
Read more: tinyurl.com/47n95ae8
#MECFS
A study has found that haptoglobin – a protein that plays a crucial role in recycling iron and protecting the body from the harm caused during oxidative stress – may be linked to post exertional malaise.
Read more: tinyurl.com/47n95ae8
#MECFS
September 4, 2025 at 9:12 PM
From ME Research UK @meresearchuk.bsky.social
A study has found that haptoglobin – a protein that plays a crucial role in recycling iron and protecting the body from the harm caused during oxidative stress – may be linked to post exertional malaise.
Read more: tinyurl.com/47n95ae8
#MECFS
A study has found that haptoglobin – a protein that plays a crucial role in recycling iron and protecting the body from the harm caused during oxidative stress – may be linked to post exertional malaise.
Read more: tinyurl.com/47n95ae8
#MECFS
"Haptoglobin könnte als translationaler Biomarker für die Patientenstratifizierung und als potenzielles therapeutisches Ziel zur Linderung von oxidativem Stress und kognitiver Dysfunktion bei ME dienen"...
#MEcfs
#MEcfs
Haptoglobin phenotypes and structural variants associate with post-exertional malaise and cognitive dysfunction in myalgic encephalomyelitis - Journal of Translational Medicine
Background Myalgic encephalomyelitis (ME) is a chronic, multisystem illness characterized by post-exertional malaise (PEM) and cognitive dysfunction, yet the molecular mechanisms driving these hallmar...
share.google
September 19, 2025 at 8:46 AM
"Haptoglobin könnte als translationaler Biomarker für die Patientenstratifizierung und als potenzielles therapeutisches Ziel zur Linderung von oxidativem Stress und kognitiver Dysfunktion bei ME dienen"...
#MEcfs
#MEcfs
Our latest study of the scavenger receptor CD163, led by Richard Zhou. This follows our previous study of how CD163 uses its remarkable molecular architecture to bind haptoglobin-haemoglobin. We now show how its flexible arms allow haemoglobin binding, revealing how ligand promiscuity works.
May 16, 2026 at 10:59 AM
Our latest study of the scavenger receptor CD163, led by Richard Zhou. This follows our previous study of how CD163 uses its remarkable molecular architecture to bind haptoglobin-haemoglobin. We now show how its flexible arms allow haemoglobin binding, revealing how ligand promiscuity works.
I texted my favorite hematologist to ask her what should be on my differential for elevated haptoglobin and LDH, and she replied “chronic inflammation.”
My old nemesis, we meet again.
My old nemesis, we meet again.
April 9, 2026 at 6:30 PM
I texted my favorite hematologist to ask her what should be on my differential for elevated haptoglobin and LDH, and she replied “chronic inflammation.”
My old nemesis, we meet again.
My old nemesis, we meet again.
10) Link to the (open-access) study:
Moezzi et al. Haptoglobin phenotypes and structural variants associate with post-exertional malaise and cognitive dysfunction in myalgic encephalomyelitis.
Moezzi et al. Haptoglobin phenotypes and structural variants associate with post-exertional malaise and cognitive dysfunction in myalgic encephalomyelitis.
Haptoglobin phenotypes and structural variants associate with post-exertional malaise and cognitive dysfunction in myalgic encephalomyelitis - Journal of Translational Medicine
Background Myalgic encephalomyelitis (ME) is a chronic, multisystem illness characterized by post-exertional malaise (PEM) and cognitive dysfunction, yet the molecular mechanisms driving these hallmark symptoms remain unclear. This study investigated haptoglobin (Hp) as a potential biomarker of PEM severity and cognitive impairment in ME, with a focus on Hp phenotypes and structural proteoforms. Methods A longitudinal case–control study was conducted in 140 ME patients and 44 matched sedentary healthy controls. In the discovery phase, global plasma proteomic profiling was performed in 61 ME patients and 20 controls before and after a standardized, non-invasive stress protocol in order to induce PEM. Associations between Hp levels, phenotype, and cognitive performance were assessed. In the validation phase, plasma Hp concentrations and proteoform composition were analyzed in an independent cohort of 89 ME patients and 24 controls using high-performance liquid chromatography (HPLC). Results ME patients demonstrated a significant reduction in Hp levels following post-exertional stress. Lower baseline Hp concentrations were associated with impaired cognitive performance. Hp phenotypes were differentially associated with symptom burden, with the Hp2-1 phenotype enriched in ME and linked to greater PEM severity and cognitive deficits compared to Hp1-1 and Hp2-2. HPLC analysis revealed altered Hp proteoform profiles in the Hp2-1 subgroup, including increased high-mass tetrameric and pentameric forms and shorter retention times indicative of structural changes. In contrast, the Hp1-1 phenotype was associated with milder symptoms and greater cognitive resilience. Conclusions These findings suggest that Hp phenotype and proteoform structure modulate the physiological response to post-exertion in ME, offering insight into the molecular basis of PEM and its clinical heterogeneity. Hp may serve as a translational biomarker for patient stratification and a potential therapeutic target to mitigate oxidative stress and cognitive dysfunction in ME.
translational-medicine.biomedcentral.com
August 30, 2025 at 11:43 AM
10) Link to the (open-access) study:
Moezzi et al. Haptoglobin phenotypes and structural variants associate with post-exertional malaise and cognitive dysfunction in myalgic encephalomyelitis.
Moezzi et al. Haptoglobin phenotypes and structural variants associate with post-exertional malaise and cognitive dysfunction in myalgic encephalomyelitis.
Université de Montreal
Faculté de médecine – Thesis
Role of haptoglobin and its phenotypic variations in the pathophysiology of myalgic encephalomyelitis and long COVID
Role of haptoglobin and its phenotypic variations in the pathophysiology of myalgic encephalomyelitis and long COVID
#ME/CFS
Faculté de médecine – Thesis
Role of haptoglobin and its phenotypic variations in the pathophysiology of myalgic encephalomyelitis and long COVID
Role of haptoglobin and its phenotypic variations in the pathophysiology of myalgic encephalomyelitis and long COVID
#ME/CFS
Role of haptoglobin and its phenotypic variations in the pathophysiology of myalgic encephalomyelitis and long COVID
L’encéphalomyélite myalgique (EM) et le COVID Long (LC) sont des maladies chroniques multi-systémiques caractérisées par un le malaise post-effort (post-exertional malaise en anglais ou PEM), des trou...
umontreal.scholaris.ca
September 28, 2026 at 1:58 AM
Université de Montreal
Faculté de médecine – Thesis
Role of haptoglobin and its phenotypic variations in the pathophysiology of myalgic encephalomyelitis and long COVID
Role of haptoglobin and its phenotypic variations in the pathophysiology of myalgic encephalomyelitis and long COVID
#ME/CFS
Faculté de médecine – Thesis
Role of haptoglobin and its phenotypic variations in the pathophysiology of myalgic encephalomyelitis and long COVID
Role of haptoglobin and its phenotypic variations in the pathophysiology of myalgic encephalomyelitis and long COVID
#ME/CFS
Haptoglobin phenotypes and structural variants associate with post-exertional malaise and cognitive dysfunction in myalgic encephalomyelitis translational-medicine.biomedcentral.com/articles/10....
A. Moreau et al. 🇨🇦
#ME/CFS #Haptaglobin #PEM
A. Moreau et al. 🇨🇦
#ME/CFS #Haptaglobin #PEM
Haptoglobin phenotypes and structural variants associate with post-exertional malaise and cognitive dysfunction in myalgic encephalomyelitis - Journal of Translational Medicine
Background Myalgic encephalomyelitis (ME) is a chronic, multisystem illness characterized by post-exertional malaise (PEM) and cognitive dysfunction, yet the molecular mechanisms driving these hallmar...
translational-medicine.biomedcentral.com
August 29, 2025 at 11:15 PM
Haptoglobin phenotypes and structural variants associate with post-exertional malaise and cognitive dysfunction in myalgic encephalomyelitis translational-medicine.biomedcentral.com/articles/10....
A. Moreau et al. 🇨🇦
#ME/CFS #Haptaglobin #PEM
A. Moreau et al. 🇨🇦
#ME/CFS #Haptaglobin #PEM
Researchers studied 140 patients with myalgic encephalomyelitis and found that a common blood protein, haptoglobin, drops after exertion.
The Hp2-1 type was linked to worse fatigue and brain fog.
translational-medicine.biomedcentral.com/articles/10....
The Hp2-1 type was linked to worse fatigue and brain fog.
translational-medicine.biomedcentral.com/articles/10....
Haptoglobin phenotypes and structural variants associate with post-exertional malaise and cognitive dysfunction in myalgic encephalomyelitis - Journal of Translational Medicine
Background Myalgic encephalomyelitis (ME) is a chronic, multisystem illness characterized by post-exertional malaise (PEM) and cognitive dysfunction, yet the molecular mechanisms driving these hallmar...
translational-medicine.biomedcentral.com
September 16, 2025 at 9:57 PM
Researchers studied 140 patients with myalgic encephalomyelitis and found that a common blood protein, haptoglobin, drops after exertion.
The Hp2-1 type was linked to worse fatigue and brain fog.
translational-medicine.biomedcentral.com/articles/10....
The Hp2-1 type was linked to worse fatigue and brain fog.
translational-medicine.biomedcentral.com/articles/10....
🔬 A new study sheds light on why people with Myalgic Encephalomyelitis (ME) experience post-exertional crashes and brain fog.
It focuses on a blood protein called haptoglobin (Hp) and how its different genetic forms affect symptoms. 🧵
It focuses on a blood protein called haptoglobin (Hp) and how its different genetic forms affect symptoms. 🧵
September 17, 2025 at 3:05 PM
🔬 A new study sheds light on why people with Myalgic Encephalomyelitis (ME) experience post-exertional crashes and brain fog.
It focuses on a blood protein called haptoglobin (Hp) and how its different genetic forms affect symptoms. 🧵
It focuses on a blood protein called haptoglobin (Hp) and how its different genetic forms affect symptoms. 🧵
3) Few proteins were significantly changed after the cuff test, but Haptoglobin stood out.
It was decreased in ME/CFS patients after the cuff test (1.84-fold change, p = 0.007), but not in healthy controls.
It was decreased in ME/CFS patients after the cuff test (1.84-fold change, p = 0.007), but not in healthy controls.
August 30, 2025 at 11:42 AM
3) Few proteins were significantly changed after the cuff test, but Haptoglobin stood out.
It was decreased in ME/CFS patients after the cuff test (1.84-fold change, p = 0.007), but not in healthy controls.
It was decreased in ME/CFS patients after the cuff test (1.84-fold change, p = 0.007), but not in healthy controls.