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ME/ CFS  &  FM  Subgroups

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CFS/ ME Subgroups

The need for subgrouping is stressed by the argument that research - or treatment trials - involving patients with CFS/ ME, cannot be compared as long as the disease definition(s) encounter several subgroups,  Jason et al., 2003. , demitrack06.txt.

 

Patients who fulfill the CDC-1994 (Fukuda et al.) definition, differ markedly according to whether or not they acquired CFS sporadically, from the Gulf War or by exposure to insecticides, kennedy.etal04.txt, kennedy.etal04.pdf.
 

Types of Subgroups

Dr. Tan et al. suggested 4 CFS subgroups based on symptoms from either organ system [the nervous system,  the musculo-sceletal system, the endocrine system, and the immune/infectious system],  Tan et al., 2002,   Tan et al., 2002 (pdf).

Dr. Jason's research group in Chicago doing community-based studies (telephone interviews), has dealt repeatedly with subgrouping.  In one study patients were divided according to disease onset, occupation etc.,  Jason et al., 2000,  and in another by symptoms,  Jason et al., 2001.  In a third study, using factor analysis, Jason et al. suggest the same grouping as Dr. Tan (above),  Jason et al., 2002.  In a very large study Jason & Taylor used cluster analysis,  Jason & Taylor, 2002 (1),  Jason & Taylor, 2002 (2).  A short paper on the existence of subgroupings based on socio-economical factors,  Jason et al., 2003.

Lately, Dr. Jason has suggested subtyping individuals with CFS on sociodemographic, functional disability, viral, immune, neuroendocrine, neurology, autonomic, and genetic biomarkers providing clarification for researchers and clinicians who encounter CFS' characteristically confusing heterogeneous symptom profiles, jason.etal05.txt, jason.etal05.pdf. Clear distinction from psychiatric disease based fatigue, song.jason05.txt, song.jason05.pdf.

Attempts by Dr. Natelson's group in Newark to prove that CFS with 'sudden onset' differ from cases with 'slow onset' in co-morbid psychology was not successful,  Cukor et al., 2000.  However, Dr. Natelson supports the notion of distinct subgroups,  Natelson, 2002,  and when it comes to birth rank, increased CFS was seen among second-borns,  Brimacombe et al., 2002.  Also in Australia attempts has been made to subdivide patients (with CF), but no convincing method was found,  Wilson et al., 2001.  An Italian research group suggests subgrouping, but does not specify the groupings,  Racciatti et al., 1999.

A Belgian study using multiple varians analysis concluded that CFS patients fulfilling Holmes et al. 1988 definition were more serious ill compared to other CFS definitions,  De Becker et al., 2001. 

The 2003-CFS Name Change proposal argues for the umbrella term NDS with 4 subgroups: ME, CFS-Fukuda, Canadian CFS-definition and GWS,  Name Change Draft, 2003.

Despite the recognition of subgroups defined by factor analysis, respected researchers from CDC, US also points out that there is considerable overlap between groups, nisenbaum.etal04.txt, nisenbaum.etal04.pdf.

Sub-typing CFS patients on the basis of 'minor' symptoms, janal.etal06.txt, janal.etal06.pdf.

Using NKCA as an immunological subgroup marker in CFS, siegel.etal06.txt, siegel.etal.06.txt, siegel.etal06.pdf.

 

FM Subgroups

FM expert, Dr. Russell wrote an interesting 2002-editorial on FM subgroups,  editorial, Russell, 2002.  Another article covers the difficulties inherent in defining subgroups,  Walen et al., 2002.
 

Artificial Neural Network

Complex diseases can be analyzed by a method named Artificial Neural Network (ANN) here used by a German group to distinguish CFS from SLE and FM,  Linder et al., 2002.
 

Contradictory Beliefs – Psychiatrists coming to light

The traditional psychiatric belief is contradictory to the above. Here psychiatrists believe all syndromes have more in common than what separates them.  CFS patients attending hospital clinics in immunology or psychiatry units share most of their symptoms,  White et al., 2002,  White et al., 2002.  However even psychiatrists read new research: Further research is needed in improving the current case definition; investigating overlaps and boundaries among various functional somatic syndromes, cho.etal06.txt, cho.etal06.pdf.  To "lump" or to "split" the functional somatic syndromes: can infectious and emotional risk factors differentiate between the onset of CFS and irritable bowel syndrome, moss-morris.etal06.txt, moss-morris.etal06.pdf.


 
 

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