Post-COVID-19 patients suffer from chemosensory, trigeminal, and salivary dysfunctions

Abstract:

Recent literature indicates that post-COVID-19 patients suffer from a plethora of complications, including chemosensory dysfunction. However, little attention has been given to understand the interactions between chemosensory, trigeminal, and salivary dysfunctions in these patients. The aims of this study were (1) to investigate the prevalence and combinations of chemosensory, trigeminal, and salivary dysfunctions, (2) to identify the odorants/tastants that are compromised, and (3) to explore possible associations between the four dysfunctions in post-COVID-19 patients.

One hundred post-COVID-19 patients and 76 healthy controls (pre-COVID-19) were included in this cross-sectional, case-controlled study. Participants’ smell, taste, trigeminal, and salivary functions were assessed. The patients had a significantly higher prevalence of parosmia (80.0%), hyposmia (42.0%), anosmia (53.0%), dysgeusia (34.0%), complete ageusia (3.0%), specific ageusia (27.0%), dysesthesia (11.0%) and dry mouth (18.0%) compared to controls (0.0% for all parameters, except 27.6% for hyposmia). Complete loss of bitter taste was the most prevalent specific ageusia (66.7%) and coffee was the most common distorted smell (56.4%). Seven different combinations of dysfunction were observed in the patients, the most common being a combination of olfactory and gustatory dysfunction (48.0%).

These findings indicate that post-COVID-19 patients experience a range of chemosensory, trigeminal, and salivary disturbances, occurring in various combinations.

Source: Rogn Å, Jensen JL, Iversen PO, Singh PB. Post-COVID-19 patients suffer from chemosensory, trigeminal, and salivary dysfunctions. Sci Rep. 2024 Feb 11;14(1):3455. doi: 10.1038/s41598-024-53919-y. PMID: 38342941; PMCID: PMC10859368. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC10859368/ (Full text)

Salivary DNA loads for human herpes viruses 6 and 7 are correlated with disease phenotype in Myalgic Encephalomyelitis/ Chronic Fatigue Syndrome

Abstract:

Myalgic Encephalomyelitis/ Chronic Fatigue Syndrome (ME/CFS) is a complex chronic condition affecting multiple body systems, with unknown cause, unclear pathogenesis mechanisms, and fluctuating symptoms which may lead to severe debilitation. It is frequently reported to have been triggered by an infection, particularly with herpes virus family members; however, there are no clear differences in exposure to, or seroprevalence of, any herpes virus in people with ME/CFS and healthy individuals. Herpes viruses exist in lytic and latent forms, and it is possible that ME/CFS is associated with viral reactivation, which has not been detectable previously due to insensitive testing methods.

Saliva samples were collected from 30 people living with ME/CFS at monthly intervals for six months and at times when they experienced symptom exacerbation, as well as from 14 healthy control individuals. The viral DNA load of the nine human herpes viruses was determined by digital droplet PCR. Symptoms were assessed by questionnaire at each time point.

Human herpes virus (HHV) 6B, HHV-7, herpes simplex virus 1 and Epstein Barr virus were detectable within the saliva samples, with higher HHV-6B and HHV-7 viral loads detected in people with ME/CFS than in healthy controls. Participants with ME/CFS could be broadly separated into two groups: one group displayed fluctuating patterns of herpes viruses detectable across the six months while the second group displayed more stable viral presentation. In the first group, there was positive correlation between HHV-6B and HHV-7 viral load and severity of symptom scores, including pain, neurocognition and autonomic dysfunction.

The results indicate that fluctuating viral load, related to herpesvirus reactivation state, may play a role in ME/CFS pathogenesis, or might be a consequence of dysregulated immune function. The sampling strategy and molecular tools developed permit large-scale epidemiological investigations.

Contribution to the Field The cause of ME/CFS and the mechanisms underlying disease pathogenesis are not known, although symptoms are often triggered by infection. Human herpes virus (HHV) family members have been implicated, although there is no difference in the seroprevalence of any HHV in people with ME/CFS and healthy controls, showing there is similar prior infection rate. HHVs exist in either latent or active, lytic, phases in the human host, and it is possible that ME/CFS symptoms and their severity is related to HHV reactivation from a latent state. We have used droplet digital PCR, a sensitive and specific method, to measure the prevalence and DNA concentration of HHVs in the saliva of people with ME/CFS and controls, and analysed the correlation with disease over a six-month timecourse. We found that two HHVs, HHV-7 and HHV-6B, were elevated in saliva from people with ME/CFS, and that in people who were severely affected by ME/CFS, the concentration HHV DNA correlated with symptom severity over time in a subgroup of patients with fluctuating salivary HHV repertoire. Our study demonstrates the feasibility of measuring HHV concentration in readily acquired samples, enabling future large-scale studies aimed at testing the causal role of HHV reactivation in ME/CFS disease.

Source: Ji-Sook Lee, Eliana M. Lacerda, Luis Nacul, Caroline C. Kingdon, Jasmin Norris, Shennae O’Boyle, Chrissy H. Roberts, Luigi Palla, Eleanor M. Riley, Jacqueline M. Cliff. Salivary DNA loads for human herpes viruses 6 and 7 are correlated with disease phenotype in Myalgic Encephalomyelitis/ Chronic Fatigue Syndrome.
medRxiv 2021.01.06.20248486; doi: https://doi.org/10.1101/2021.01.06.20248486 https://www.medrxiv.org/content/10.1101/2021.01.06.20248486v1.full-text  (Full text)

Clinicopathological findings consistent with primary Sjögren’s syndrome in a subset of patients diagnosed with chronic fatigue syndrome: preliminary observations

Abstract:

OBJECTIVE: Some patients diagnosed with chronic fatigue syndrome (CFS) have symptoms commonly observed in Sjögren’s syndrome (SS), particularly xerophthalmia and xerostomia, leading to speculation that some patients with CFS might have primary SS or that the 2 disorders share common pathophysiological features. We investigated the prevalence of symptoms of mucosal dryness, salivary gland pathology, lacrimal hyposecretion, and autoantibodies (antinuclear antibody, SSA/SSB) among patients diagnosed with CFS.

METHODS: Twenty-five subjects with CFS and 18 healthy control subjects were interviewed and examined, had a Schirmer test and fluorescein tear dilution, and underwent minor salivary gland (MSG) biopsy. Antibody to nuclear antigen as well as anti-La (SSA) and anti-Ro (SSB) antibody were available for subjects with CFS. Pathologists unaware of the subject group assignment examined labial salivary gland biopsy specimens and calculated a standard MSG score for each specimen.

RESULTS: Mucosal dryness was reported by 13/25 (52%) subjects with CFS, of which 8 (32%) also had MSG score, low Schirmer test value, and symptoms consistent with primary SS (p = 0.05). No control subject met diagnostic criteria for primary SS. MSG focus scores < or =1 were common among both groups (CFS 14/25; controls 15/18). MSG results without pathological alteration were rare, seen in only one control and no CFS patients. Low Schirmer values were found in 10/25 (40%) CFS patients and 1/18 (6%) control (p = 0.01).

CONCLUSION: A subset of patients with CFS may have primary SS.

 

Source: Sirois DA, Natelson B. Clinicopathological findings consistent with primary Sjögren’s syndrome in a subset of patients diagnosed with chronic fatigue syndrome: preliminary observations. J Rheumatol. 2001 Jan;28(1):126-31. http://www.ncbi.nlm.nih.gov/pubmed/11196514

 

Salivary gland changes in chronic fatigue syndrome: a case-controlled preliminary histologic study

Abstract:

OBJECTIVE: The purpose of this preliminary study is to compare labial salivary gland changes of 11 patients with chronic fatigue syndrome with control subjects.

STUDY DESIGN: Changes in labial salivary glands were graded from 0 to 3+ for acinar dilatation, ductal dilatation, periductal fibrosis, plasmacytic infiltrate, lymphocytic infiltrate, mast cell infiltrate, and lymphocytic aggregates or foci.

RESULTS: Four of the 11 subjects had 2+ to 3+ changes in at least 4 of the 7 parameters examined. Only the presence of mast cells was statistically significant between the 2 groups. Two of these 4 patients had 1 lymphocytic focus per 4 mm(2) of tissue.

CONCLUSIONS: The salivary gland changes in patients with chronic fatigue syndrome show varying degrees of ductal and acinar dilatation, periductal fibrosis, lymphoplasmacytic infiltrates, and occasional lymphocytic foci, all suggestive of primary gland damage. The one parameter that showed statistical significance was the presence of mast cells (Fisher exact test, 0.0125).

 

Source: Woo SB, Schacterle RS, Komaroff AL, Gallagher GT. Salivary gland changes in chronic fatigue syndrome: a case-controlled preliminary histologic study. Oral Surg Oral Med Oral Pathol Oral Radiol Endod. 2000 Jul;90(1):82-7. http://www.ncbi.nlm.nih.gov/pubmed/10884641