Mitochondrial abnormalities in the postviral fatigue syndrome 1991 Behan et al

[Andy]

Summary

We have examined the muscle biopsies of 50 patients who had postviral fatigue syndrome (PFS) for from 1 to 17 years. We found mild to severe atrophy of type II fibres in 39 biopsies, with a mild to moderate excess of lipid. On ultrastructural examination, 35 of these specimens showed branching and fusion of mitochondrial cristae. Mitochondrial degeneration was obvious in 40 of the biopsies with swelling, vacuolation, myelin figures and secondary lysosomes. These abnormalities were in obvious contrast to control biopsies, where even mild changes were rarely detected. The findings described here provide the first evidence that PFS may be due to a mitochondrial disorder precipitated by a virus infection.

Paywall, https://link.springer.com/article/10.1007/BF00294431

 

[Amw66]

1991.
Let that sink in .
Where would we be with decent funding and BPS bypass ..

 

[JemPD]

Yes and look at all the studies listed below it from the 80s... havent read them but... be interesting to get a sense of their quality.

@Andy have you read the study? i havent the energy right now but just wondering whether the controls were sedentary or active. If the controls were active people then the results could perhaps just what happens to muscles that arent used much??? Surely that was looked at the time?

 

[Sean]

be interesting to get a sense of their quality.

Even if they were not the best quality, at the very least they should have been followed up with better quality studies.

Why weren't they?

 

[Andy]

@Andy have you read the study? i havent the energy right now but just wondering whether the controls were sedentary or active. If the controls were active people then the results could perhaps just what happens to muscles that arent used much??? Surely that was looked at the time?

No, I've not read it as it is paywalled.

 

[SNT Gatchaman]

Very liberal quoting, with my bold emphasis, to give both summary and context.

The postviral fatigue syndrome (PFS) is a disease of unknown aetiology, developing after a definite viral infection and characterized by severe fatigue and myalgia, together with a variety of psychiatric and other symptoms. About one-third of patients also complain of palpitations and/or unsteadiness. Routine laboratory tests are normal but specialised investigations of muscle reveal myopathic features on single fibre electromyography and an unusually early intracellular acidosis on exercising using nuclear magnetic resonance testing. About 70 % of muscle biopsies reveal moderate atrophy of type II fibres with no other specific features. Auditory brain stem and eye motility responses have also been recorded as abnormal. Formal psychological tests in our laboratory have revealed defects in sustained concentration and a curious sensitivity to visually disturbing patterns (in preparation).

The lack of specific diagnostic criteria has made it very difficult to study the disease and, until recently, it has not been the subject of scientific investigation. Attempts have now been made to set strict guidelines for diagnosis, with a working case definition. Unfortunately, the term " chronic fatigue syndrome" has been selected and this will certainly lead to severe problems since fatigue is a feature common to so many, diverse, medical and psychiatric diseases. We prefer the term "postviral fatigue syndrome" and select all our cases on the basis that the muscle fatigue and myalgia started at the time of a viral infection and have been continuous since then. The fatigue appears to have a central nervous system component because there is no lack of power on testing but the patient has to make a determined effort to carry out simple routine tasks. It is also invariably accompanied by depression, a reduced ability to concentrate and a decrease in intellectual performance.

There are some clues as to the aetiology of the syndrome: viruses have been isolated in rare cases and high titres to coxsackie antibodies have been detected in a few, small series, although results in a later, larger study were not convincing. Nucleic acid hybridisation studies have provided additional support for a viral aetiology: 20% of 96 cases were found to have enteroviral RNA sequences in samples of their muscles, while another 10% had sequences which hybridised to an Epstein-Barr virus-specific probe. Finally, using the more sensitive polymerase chain reaction we have confirmed that enteroviral-specific sequences can be found in 53% of cases.

In spite of this evidence of viral involvement, muscle biopsies from our carefully selected group of patients showed none of the histological features of inflammation or necrosis. Ultrastructural examination, however, revealed obvious mitochondrial damage, suggesting for the first time that this may be the pathogenesis of PFS.

 

[SNT Gatchaman]

Fifty patients were studied, 19 males and 31 females. The ages of the men ranged from 17 to 49 years (mean 34.2 years) and that of the women from 16 to 50 years (mean 35 years). They were selected because of the severity of their symptoms which had been present for 6 months to 17 years, (mean 4.1 years).

The symptoms [...] consisted of overwhelming fatigue made worse by exercise, myalgia, a reduced ability to concentrate, loss of short-term memory and depression. The majority had also had palpitations at some stage and unsteadiness. Their symptoms started at the time of the original illness and had persisted since then. Seven cases had been admitted to hospital at their initial presentation because of the severity of the symptoms.

No patients were taking medication when they were studied. Previously they had all had good work records: there were 3 full-time housewives among the 31 women but all the rest had additional jobs. The occupations of the patients ranged from teachers (8 cases, including a university professor) to hospital workers (9, including a chief pharmacist and a physicist), engineering workers (9) and office workers (5).The teachers included 3 who taught physical education and there were 6 other keep-fit enthusiasts including a marathon runner and a county class badminton player. No patients had previously been referred to a psychiatrist. Two patients reported siblings developing infectious mononucleosis at the same time as themselves but recovering completely, while in 4 cases, other family members had had the influenza-like illness but again recovered. There were, however, 2 cases who had affected relatives - a woman whose mother and brother developed the disease after her, and a man whose niece was ill. Five patients had identified another 1 or 2 people at their work place who had developed the same illness after themselves.

[...] Immunological studies included immunoglobulin concentrations, complement component estimations, antinuclear antibodies and rheumatoid factor determinations. A detailed evaluation of hypothalamic function was also made. Percentage populations of T and B lymphocytes were determined in 35 of the patients. Electromyography and needle muscle biopsies were carried out. Lumbar punctures, testing of visual evoked responses, a CT scan and nuclear imaging of muscle were done in 5 cases where an alternative diagnosis had been raised. No patient was admitted to the study if he or she had any other condition which might explain even some of the findings.

Three cores of skeletal muscle were obtained from each case from the right or left vastus lateralis muscle

As control samples, 50 1-mm3 samples of skeletal muscle were obtained over the same period of time, from the operative site of patients undergoing various surgical procedures [...] The women were all undergoing either lumpectomy or mastectomy for benign (12) or malignant (18) breast disease, while the men had hernial repairs or vascular surgery. None of these patients had a muscle disease.

 

[SNT Gatchaman]

Light microscopy examination revealed only one consistent abnormality, present in 39 cases, and that was type II atrophy which ranged from mild and focal (6 cases) to moderate and diffuse (33). Four cases also had mild type I atrophy. One or two necrotic fibres were identified in three of the specimens, a tiny inflammatory focus in another two, and evidence of regeneration in a further four. One case had two ragged-red fibres on the Gomori stain: in 25 other cases, this stain identified unusually prominent mitochondria, especially in the type 1 fibres, but the typical ragged-red appearance was not present. The enzyme stains revealed 1 patient with adenylate deaminase deficiency and 24 cases with a mild to moderate excess of lipid present.

Evidence of mitochondrial abnormalities was present in 40 of the cases (80%) with the commonest change (seen in 70%) being branching and fusion of cristae, producing "compartmentalisation". Mitochondrial pleomorphism, size variation and occasional focal vacuolation were detectable in 64%, together with secondary lysosomes.

Groups of mitochondria, together with the nucleus and abundant glycogen, were present in a sub-sarcolemmal position and also scattered between muscle fibres with their long axis parallel to that of the fibres. They showed severe pleomorphism of shape and size. Their sizes ranged from 0.3 µm to 1 µm in maximum diameter, while the shape was rounded, angulated or sinuous. Expanded areas of variable shape were continuous with more conventional long sinuous types. In some instances, however, they were grossly irregular with pseudopodia-like projections thrown out at right angles to the main body of the mitochondrion.

The cristae were conventionally transverse in some cases but in others, longitudinally orientated cristae predominated; in a proportion, both forms were found. In many mitochondria branching of the cristae was a prominent feature, such that the interior of the mitochondrion was converted into a series of compartments. These compartments varied in appearance, the majority being rounded although some were angular. In some instances, they were of a uniform size within a given mitochondrion, whilst other showed a marked size variation. Some compartments could be seen to fill the whole body of the mitochondrion while others were confined to the outer membrane area. At the sites where the branching or fusion of cristae took place there was some loss of the parallel arrangement of the membranes of the cristae. No true zig-zag or concentric cristae were seen. No crystalline or paracrystalline inclusions were found and mitochondrial granules were scanty.

Vacuolation of mitochondria was frequent although variable in extent. In some cases there was swelling of the whole mitochondrion with rupture of the outer membranes and continuity of the matrix space with the general cell cytoplasm. In others, only a portion of the mitochondrion was swollen, centered quite obviously on one of the compartments formed as described above. Such limitation of the swelling suggested that these were closed compartments, subject to selective damage, although it is true to say that usually the rest of the mitochondrion was also damaged but to a lesser extent.

Lipid globules were commonly found ranging in size from 0.2 µm to 3 µm in diameter. They were scattered at random through the cell or in small groups in association with the sarcolemnal membranes.

Secondary lysosomes were prominent in some of the worst-affected cases, associated with the mitochondria, nucleus and glycogen at the cell periphery. The varied in size from 0.5 µm to 3.5 µm and in appearance containing lipid of variable density, membranes, granular debris and vacuoles. Rare areas of myofibrillary degeneration were present where the mitochondria were found with their long axes at right angles to their normal orientation as well as in the more usual positions.

Examination of the 50 control biopsies revealed no mitochondrial pleomorphism. There was minor size variation, as expected since both type I and type II fibres were examined. Rare focal vacuolation was detectable in 52%, of very mild degree and not comparable to the gross change visible in the patient biopsies. With regard to compartmentalisation, none of the samples revealed the severe changes seen in patients with PFS but on careful examination, some occasional compartments in a rare mitochondrion could be found.

The pleomorphism of the mitochondria in the patients' muscle biopsies was in clear contrast to the findings in the normal control biopsies.

 

[SNT Gatchaman]

Scientific study of the postviral fatigue syndrome (PFS) has been bedevilled by the difficulty in diagnosis and the absence of fibre necrosis on routine histology. Nonetheless, diffuse or focal atrophy of type II fibres has been reported, and this, although non-specific, does indicate muscle damage and not just muscle disuse. In addition, specialised tests have revealed electrophysiological and metabolic muscle abnormalities and recent reports suggest that a persistent local enteroviral infection may be present.

In the study reported here we found that the mitochondria in 80% of the biopsies from patients with PFS showed an unusual appearance, consisting of branching and fusion of the cristae which produced the appearance of compartmentalisation within the organelle.

In general the number of cristae within a mitochondrion is thought to reflect its level of activity; normal muscle mitochondria have more cristae than those of liver. Branching and fusion of cristae (compartmentalisation) or a honeycomb appearance, along with other structural abnormalities, are seen at their most frequent and florid in the mitochondrial myopathies. Indeed, although not correlating with any specific metabolic lestion, defects involving the respiratory chain or components of the energy conservation or transducing systems have consistently shown major alterations in mitochondrial structure and number. It is assumed that the usual sequence of metabolic steps is disturbed in these cases, leading to accumulation of a metabolite and attempts at compensation.

The morphological changes which occur in mitochondrial myopathies do have one feature in common: they all represent an increase: the organelles are more numerous, larger and pleomorphic, developing abundant, branched cristae, show an increased matrix and are surrounded by more and larger triglyceride droplets. Sometimes crystalline or paracrystalline structures are found. These changes are similar those we detected in our cases of PFS except that we found no inclusions.

We have not yet carried out any functional studies of the mitochondria in PFS but other workers have reported mild depression of state 3 respiration rates using sites I and II substrates in two cases. P31 nuclear magnetic resonance tests on patients have shown an abnormally rapid fall in phosphocreatine during light aerobic exercise, similar to cases of coenzyme Q reductase deficiency.

In summary, we are not putting forward the muscle damage found here as specific for PFS but suggest our results show that mitochondrial lesions may be present in the muscle, that they may explain many of the clinical and laboratory features and that they suggest a new way of investigating the disease.

 

[SNT Gatchaman]

just wondering whether the controls were sedentary or active. If the controls were active people then the results could perhaps just what happens to muscles that arent used much??? Surely that was looked at the time?

As control samples, 50 1-mm3 samples of skeletal muscle were obtained over the same period of time, from the operative site of patients undergoing various surgical procedures and treated in the same manner as above. The samples were from pectoralis major, rectus abdominis and vastus medialis muscles. The patients consisted of 30 females aged from 24 to 71 years (mean 51.4 years and 20 males, from 18 to 73 years (mean 59.8 years). The women were all undergoing either lumpectomy or mastectomy for benign (12) or malignant (18) breast disease, while the men had hernial repairs or vascular surgery. None of these patients had a muscle disease.

So not specifically sedentary controls. However, they note the type II atrophy, some necrosis and regeneration, which is described in the upcoming Wüst et al paper in LC - increasing post exercise challenge. The metabolic findings on P31 NMR and EM mitochondrial findings are not those of disuse / deconditioning.

 

[Sid]

This study was discussed years ago on the previous forum. My recollection is that none of Behan's stuff could be replicated elsewhere.

 

[dreampop]

If the NIH study accomplishes nothing else you would think it would be looking at this kind of stuff and hopefully clarify research that was never followed up on. I don't know if that was the case here.

 

[Hutan]

I don't think the NIH study (Walitt - Deep phenotyping) looked at mitochondrial structure, which is a desperate shame.

The findings do sound compelling and the excerpts read well to me - I can see why people who were reading these studies when they came out might be convinced that this evidence is solid. However, the authors of this paper themselves weren't saying 'here we have the ME/CFS biomarker'.

I guess there has been a problem in getting more studies done, especially given biopsies are required. I don't think we have enough evidence at this point to make claims about abnormalities in mitochondrial structure.

 

[Jesse]

Does Wüst’s work have any relevance here?

Edit: I guess we're still waiting on the ME/CFS data?

 

[jnmaciuch]

Lawson et al. 2016 looked at mitochondrial structure in PBMCs and found them normal. However, I don’t think anything found in the muscle would be expected to also show up in PBMCs.

There’s a chance Maureen Hanson’s upcoming study on spatial transcriptomics will also include some light microscopy but I don’t know for sure. I sent Rob Wust an email a while back, his response suggested he didn’t have any mitochondrial imaging either (though didn’t mention anything specifically to confirm or deny)

I’d really like to see this followed up on, though.

 

[DMissa]

Our lab is exploring this area