Tag: genetics

Chronic fatigue syndrome: progress and possibilities

Abstract:

Chronic fatigue syndrome (CFS) is a prevalent condition affecting about one in 100 patients attending primary care. There is no diagnostic test, validated biomarker, clear pathophysiology or curative treatment. The core symptom of fatigue affects both physical and cognitive activities, and features a prolonged post-activity exacerbation triggered by tasks previously achieved without difficulty.

Although several different diagnostic criteria are proposed, for clinical purposes only three elements are required: recognition of the typical fatigue; history and physical examination to exclude other medical or psychiatric conditions which may explain the symptoms; and a restricted set of laboratory investigations. Studies of the underlying pathophysiology clearly implicate a range of different acute infections as a trigger for onset in a significant minority of cases, but no other medical or psychological factor has been reproducibly implicated.

There have been numerous small case-control studies seeking to identify the biological basis of the condition. These studies have largely resolved what the condition is not: ongoing infection, immunological disorder, endocrine disorder, primary sleep disorder, or simply attributable to a psychiatric condition. A growing body of evidence suggests CFS arises from functional (non-structural) changes in the brain, but of uncertain character and location. Further functional neuroimaging studies are needed.

There is clear evidence for a genetic contribution to CFS from family and twin studies, suggesting that a large scale genome-wide association study is warranted. Despite the many unknowns in relation to CFS, there is significant room for improvement in provision of the diagnosis and supportive care. This may be facilitated via clinician education.

Source: Sandler CX, Lloyd AR. Chronic fatigue syndrome: progress and possibilities. Med J Aust. 2020 Apr 5. doi: 10.5694/mja2.50553. [Epub ahead of print] https://www.ncbi.nlm.nih.gov/pubmed/32248536

Myalgic Encephalomyelitis/Chronic Fatigue Syndrome: A Comprehensive Review

Abstract:

Myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS) is a debilitating chronic disease of unknown aetiology that is recognized by the World Health Organization (WHO) and the United States Center for Disease Control and Prevention (US CDC) as a disorder of the brain. The disease predominantly affects adults, with a peak age of onset of between 20 and 45 years with a female to male ratio of 3:1. Although the clinical features of the disease have been well established within diagnostic criteria, the diagnosis of ME/CFS is still of exclusion, meaning that other medical conditions must be ruled out.

The pathophysiological mechanisms are unclear but the neuro-immuno-endocrinological pattern of CFS patients gleaned from various studies indicates that these three pillars may be the key point to understand the complexity of the disease. At the moment, there are no specific pharmacological therapies to treat the disease, but several studies’ aims and therapeutic approaches have been described in order to benefit patients’ prognosis, symptomatology relief, and the recovery of pre-existing function.

This review presents a pathophysiological approach to understanding the essential concepts of ME/CFS, with an emphasis on the population, clinical, and genetic concepts associated with ME/CFS.

Source: Cortes Rivera M, Mastronardi C, Silva-Aldana CT, Arcos-Burgos M, Lidbury BA. Myalgic Encephalomyelitis/Chronic Fatigue Syndrome: A Comprehensive Review. Diagnostics (Basel). 2019 Aug 7;9(3). pii: E91. doi: 10.3390/diagnostics9030091. https://www.ncbi.nlm.nih.gov/pubmed/31394725

Chronic fatigue syndrome in mother and child

Comment on: The course of severe chronic fatigue syndrome in childhood. [J R Soc Med. 2000]

This comment is about the genetic condition, osteoarthritis. You can read the full comment here: http://www.ncbi.nlm.nih.gov/pmc/articles/PMC1298053/pdf/10911845.pdf

 

Source: Sweetman BJ. Chronic fatigue syndrome in mother and child. J R Soc Med. 2000 Jun;93(6):337-8. http://www.ncbi.nlm.nih.gov/pmc/articles/PMC1298053/

 

Review of juvenile primary fibromyalgia and chronic fatigue syndrome

Abstract:

This article reviews the current literature on childhood fibromyalgia and chronic fatigue syndrome. In doing so, it questions assumptions about the presumed nature of the disorders-that they are distinct from each other and are duplicates of their adult counterparts. It also attempts to synthesize the available data to reach some preliminary judgments about these disorders: that fibromyalgia and chronic fatigue syndrome may be related in children and may not be duplicates of the adult disorders; that psychological and psychosocial factors are unlikely contributors to the etiology of these disorders; and that the evidence is increasingly pointing to a role for genetic factors in their etiology. A discussion of the research into treatments for childhood fibromyalgia and chronic fatigue syndrome highlights the lack of well-designed, controlled studies. Finally, directions for future research are offered where results of the current literature are unclear.

 

Source: Breau LM, McGrath PJ, Ju LH. Review of juvenile primary fibromyalgia and chronic fatigue syndrome. J Dev Behav Pediatr. 1999 Aug;20(4):278-88. http://www.ncbi.nlm.nih.gov/pubmed/10475602

 

MELISA-an in vitro tool for the study of metal allergy

Abstract:

The sensitizing properties of metals widely used in medical and dental care have been studied with the help of an optimized lymphocyte proliferative assay, MELISA. MELISA (memory lymphocyte immuno-stimulation assay) was originally developed for the screening of allergenic epitopes of drugs and other chemicals of low molecular weight, but has recently been adapted for the study of metal-induced sensitization.

The patients studied suffered from various oral mucosal problems which were suspected to be caused by the release of metal ions from dental restorations. They were also troubled by chronic fatigue persisting over many years. One patient was also occupationally exposed to metals while working in a dental practice. Healthy subjects without any discomfort due to metal devices served as controls. In addition to metals used in dentistry, lymphocyte responses to organic mercurials used widely as preservatives in vaccines, eye/nose drops and contact lense fluids were studied.

The results indicated that mercurials, as well as other metals such as gold or palladium, induce strong lymphocyte proliferative responses in patients with oral or systemic symptoms, but not in similarly exposed unaffected subjects.

The results of MELISA performed with a pair of identical twins with chronic fatigue syndrome (CFS) indicated that metal-specific responses may be dependent on the genetics of the patient. Thus, many metals that are today accepted for use in medicine and dentistry carry a definite sensitizing risk for certain genetically predisposed individuals. Therefore, the use of these metals should be limited in the future.

 

Source: Stejskal VD, Cederbrant K, Lindvall A, Forsbeck M. MELISA-an in vitro tool for the study of metal allergy. Toxicol In Vitro. 1994 Oct;8(5):991-1000. http://www.ncbi.nlm.nih.gov/pubmed/20693060