I cannot die

I cannot die

For most ME/CFS patients (about two thirds), the disease has an oscillating course, with some periods of improvements followed by worsening of symptoms. Some of them can even experience recoveries, only to find themselves trapped again, weeks or months later (Stoothoff J et al. 2017), (Chu L. et al. 2019). Some anecdotes suggest that there might be a correlation with seasons, with improvements in summer, but there are no systematic surveys on that, to my knowledge.

As for me, in the last 20 years of pitiful combat with this monster, I experienced some substantial short-lived improvements, mainly during the core of summer. At the very beginning of the disease, I also recovered for a year. It was the year 2001, I was 21 and that year has been the only period of normality in my whole adult life. I spent these 12 months studying desperately and what I am as a person is mainly due to what I learned back then. I had already been very sick for about two years and when I recovered, it was as if I were born again. It was a second chance and I was determined to do all right from day one. I decided what was really important to me and I devoted myself to my goal: learning quantitative methods to use in engineering and – one day – in biology.

When darkness caught me again, I was, among other things, reviewing all the main theorems of calculus (particularly those about differential equations) with my new skills and I remember thinking that I was becoming good at developing my own proofs. I had become good at thinking and so, I reasoned, I could finally start my life! But in a few weeks, my mind faded away, and there was nothing I could do to keep a grip to all my beloved notes and books. They became mute and closed as monolithic gravestones. I remember clearly that along with this severe and abrupt cognitive decline, I developed also orthostatic intolerance, even though I hadn’t a name for it back then. But I couldn’t keep sitting, and I didn’t know why. I was forced to lay as if the gravitational acceleration had suddenly increased. My brain had changed to a lifeless stone, and so did my body.

From that very moment, my only thought has been how could I go back to my books and my calculations. And this still is my first thought, when I wake up in the morning. After almost 20 years.

I have experienced some short improvements in these years, during which I had to learn again how to study, how to do calculations, how to code. I never went back to what I was, though. And my brain is ageing, of course, as anyone else’s brain does. But in these short periods of miraculous come back I experience a rare sense of joy (along with anger and fear). Something that you can experience only if you have been facing death.

I was born and I died dozens of times in the last 20 years, and this gives me the perception that, in fact, I cannot die: I feel as if I were immortal and I had lived for a thousand years while at the same time still being in my twenties, since I have no experience of life.

In fact, I lived only when I crossed these short bridges from one abyss to the following one.

 

Immunosignature analysis of a ME/CFS patient. Part 1: viruses

Immunosignature analysis of a ME/CFS patient. Part 1: viruses

The purpose of the following analysis is to search for the viral epitopes that elicited – in a ME/CFS patient – IgGs against a set of 6 peptides, determined thanks to an array of 150.000 random peptides of 16 amino acids each. These peptides were used as query sequences in a BLAST search against viral proteins. No human virus was found. Three phages of bacterial human pathogens were identified, belonging to the classes Actinobacteria and γ-Proteobacteria. One of these bacteria, Serratia marcescens, was identified in a similar study on 21 ME/CFS cases.  

1. The quest for a pathogen

Scientists have been speculating about an infectious aetiology of ME/CFS for decades, without never being able to link the disease to a specific pathogen. The idea that the disease might be triggered and/or maintained by an infection is due to the observation that for most of the patients the onset occurs after an infectious illness (Chu, L. et al. 2019). It has also been observed that after a major infection (whether parasitic, viral or bacterial) about 11% of the population develops ME/CFS (Mørch K et al. 2013), (Hickie I. et al. 2006).

In recent years, the advent of new technologies for pathogen hunting has given renewed impulse to the search for ongoing infection in this patient population. A 2018 study, investigating the genetic profile of peripheral blood for prokaryotic and eukaryotic organisms reported that most of the ME/CFS patients have DNA belonging to the eukaryotic genera Perkinsus and Spumella and to the prokaryotic class β-proteobacteria (alone or in combination) and that these organisms are statistically more present in patients than in controls (Ellis J.E. et al. 2018). Nevertheless, a previous metagenomic analysis of plasma by another group revealed no difference in the content of genetic material from bacteria and viruses between ME/CFS patients and healthy controls (Miller R.R. et al. 2016). Moreover, metagenomic analysis pursued in various samples from ME/CFS patients by both Stanford University and Columbia University has come empty (data not published, R, R).

2. Immunological methods

Another way of investigating the presence of current and/or past infections that might be specific of this patient population is to extract the information contained in the adaptive immune response. This can be made in several ways, each of them having their own limits. One way would be to collect the repertoire of T cell receptors (TCRs) of each patient and see if they have been elicited by some particular microorganism. This is a very complex and time-consuming method that has been developed in recent years and that I have described in details going through all the recent meaningful publications (R). The main limitation of this method is that, surprisingly, TCRs are not specific for a single epitope (Mason DA 1998), (Birnbaum ME et al. 2014), so their analysis is unlikely to reveal what agent selected them. On the other hand, the advantage of this method is that T cell epitopes are linear ones, so they are extremely suited for BLAST searches against protein databases. An attempt at applying this method to ME/CFS is currently underway: it initially gave encouraging results (R), then rejected by further analysis.

Another possible avenue for having access to the information registered by adaptive immunity is to investigate the repertoire of antibodies. The use of a collection of thousands of short random peptides coated to a plate has been recently proposed as an efficient way to study the response of B cells to cancer (Stafford P. et al. 2014), infections (Navalkar K.A. et al. 2014), and immunization (Legutki JB et al. 2010). This same method has been applied to ME/CFS patients and it has shown the potential of identifying an immunosignature that can differentiate patients from controls (Singh S. et al. 2016), (Günther O.P. et al. 2019). But what about the antigens eliciting that antibody profile? Given a set of peptides one’s antibodies react to, a possible solution for interpreting the data is to use these peptides as query sequences in a BLAST search against proteins from all the microorganisms known to infect humans. This has been done for ME/CFS, and the analysis led to several matches among proteins from bacteria, viruses, endogenous retroviruses and even human proteins (in fact, both this method and the one previously described can detect autoimmunity as well) (Singh S. et al. 2016).  There are several problems with this approach, though. First of all, the number of random peptides usually used in these arrays is not representative of the variety of possible epitopes of the same length present in nature. If we consider the paper by Günther O.P. and colleagues, for instance, they used an array of about 10^5 random peptides with a length of 12 amino acids each, with the number of all the possible peptides of the same length being  20^12 ∼ 4·10^15. This means that many potential epitopes one has antibodies to are not represented in the array. Another important limitation is that B cell epitopes are mainly conformational ones, which means that they are assembled by the folding of the proteins they belong to (Morris, 2007), the consequence of this being that the subset of random peptides one’s serum react to are in fact linear epitopes that mimic conformational ones (they are often called mimotopes) (Legutki JB et al. 2010). This means that a BLAST search of these peptides against a library of proteins from pathogens can lead to completely misleading results.

Recently an array of overlapping peptides that cover the proteins for many know viruses has been successfully used for the study of acute flaccid myelitis (AFM). This technology, called VirScan, has succeeded in linking AFM to enteroviruses where metagenomic of the cerebrospinal fluid has failed (Shubert R.D. et al. 2019). This kind of approach is probably better than the one employing arrays of random peptides, for pathogen hunting. The reason being that a set of only 150.000 random peptides is unlikely to collect a significant amount of B cell epitopes from viruses, bacteria etc. Random peptides are more suited for the establishment of immunosignatures.

3. My own analysis

I have recently got access to the results of a study I was enrolled in two years ago. My serum was diluted and applied to an array of 150.000 peptides with a length of 16 random amino acids (plus four amino acids used to link the peptides to the plate). Residues Threonine (T), Isoleucine (I) and Cysteine (C) were not included in the synthesis of peptides. Anti-human-IgG Ab was employed as a secondary antibody. The set of peptides my IgGs reacted to has been filtered with several criteria, one of them being subtracting the immune response common to healthy controls, to have an immune signature that differentiates me from healthy controls. The end result of this process is the set of the following six peptides.

1 ALHHRHVGLRVQYDSG
2 ALHRHRVGPQLQSSGS
3 ALHRRQRVLSPVLGAS
4 ALHRVLSEQDPQLVLS
5 ALHVRVLSQKRPLQLG
6 ALHLHRHVLESQVNSL

Table 1. My immunosignature, as detected by an array of 150.000 random peptides 20-amino-acid long, four of which are used for fixing them to the plate and are not included here.

The purpose of the following analysis is to search for the viral epitopes that elicited this immune response. To overcome the limitations enumerated at the end of the previous paragraph I have decided to search within the database of viral proteins for exact matches of the length of 7 amino acids. Why this choice? A survey of a set of validated B cell epitopes found that the average B cell epitope has a linear stretch of 5 amino acids (Kringelum, et al., 2013); according to another similar work, the average linear epitope within a conformational one has a length of 4-7 amino acids (Andersen, et al., 2006). To filter the matches and to reduce the number of matches due to chance, I opted for the upper limit of this length. I excluded longer matches to limit the number of mimotopes for conformational epitopes. Moreover, I decided to look only for perfect matches (excluding the possibility of gaps and substitutions) so to simplify the analysis. It is worth mentioning that a study of cross-reactive peptides performed for previous work (Maccallini P. et al. 2018) led me to the conclusion that cross-reactive 7-amino-acid long peptides might often have 100% identity.

Sample
Figure 1. For each match, the matching protein and the organism it belongs to are reported. The protein ID has a link to the NCBI protein database, while the name of the organism has a link to the NCBI taxonomy browser. The host of the microorganism is also indicated, as well as its habitat, with links to further information.

4. Results

Table 2 is a collection of the matches I found with the method described above. You can look at figure 1 to see how to read the table.

ALHHRHVGLRVQYDSG (102_1_F_viruses)
9-LRVQYDS-15
QDP64279.1(29-35)
Prokaryotic dsDNA virus sp.
Archea, Ocean
8-GLRVQYD-14
AYV76690.1(358-364)
Terrestrivirus sp
Amoeba, forest soil
ALHRHRVGPQLQSSGS (102_2_F_viruses)
2-LHRHRVG-8
YP_009619965.1(63-69)
Stenotrophomonas phage vB_SmaS_DLP_5
Stenotrophomonas maltophilia (HP)
ALHRRQRVLSPVLGAS (102_3_F_viruses)
8-VLSPVLG-14
QDB71078.1 (24-30)
Serratia phage Moabite
Serratia marcescens (HP)
ALHRVLSEQDPQLVLS (102_4_F_viruses)
7-SEQDPQL-13
BAR30981.1 (151-157)
uncultured Mediterranean phage uvMED
Archea and Bacteria, Med. sea
ALHLHRHVLESQVNSL (102_6_F_viruses)
2-LHLHRHV-8
YP_009119106.1 (510-516)
Pandoravirus inopinatum
Acanthamoeba
4-LHRHVLE-10
ASZ74651.1 (61-67)
Mycobacterium phage Phabba
Mycobacterium smegmatis mc²155 (HP)

Table 2. Collection of the matches for the BLAST search of my unique set of peptides against viral proteins (taxid 10239). HP: human pathogen. See figure 1 for how to read the table.

5. Discussion

The are no human viruses detected by this search. There are some bacteriophages and three of them have as hosts bacteria that are known to be human pathogens. Bacteriophages (also known as phages) are viruses that use the metabolic machinery of prokaryotic organisms to replicate (figure 2). It is well known that bacteriophages can elicit specific antibodies in humans: circulating IgGs to naturally occurring bacteriophages have been detected (Dąbrowska K. et al. 2014) as well as specific antibodies to phages injected for medical or experimental reasons (Shearer WT et al. 2001), as reviewed here: (Jonas D. Van Belleghem et al. 2019). According to these observations, one might expect that when a person is infected by a bacterium, this subject will develop antibodies not only to the bacterium itself but also to its phages.

phage
Figure 2. Half of all viruses have an almost regular icosahedral shape, but several phages present an irregular icosahedral shape, with a prolate capsid (Luque and Reguera 2013). On the left a wrong representation of a phage. It is wrong because the capsid has 24 faces, instead of 20. On the right, the representation of a regular icosahedron made by Leonardo Da Vinci for De Divina Proportione, a mathematical book by Luca Pacioli.

If that is the case, we can use our data in table 2 to infer a possible exposure of our patient to the following bacterial pathogens: Stenotrophomonas maltophilia (HP), Serratia marcescens (HP), Mycobacterium smegmatis mc²155 (HP). In brackets, there are links to research about the pathogenicity for humans of each species. M. smegmatis belongs to the class Actinobacteria, while S. maltophila and S. marcescens are included in the class γ-Proteobacteria.

Interesting enough, Serratia marcescens was identified as one of the possible bacterial triggers for the immunosignature of a group of 21 ME/CFS patients, in a study that employed an array of 125.000 random peptides (Singh S. et al. 2016). This bacterium accounts for rare nosocomial infections of the respiratory tract, the urinary tract, surgical wounds and soft tissues. Meningitis caused by Serratia marcescens has been reported in the pediatric population (Ashish Khanna et al. 2013).

6. Next step

The next step will be to perform a similar BLAST search against bacterial proteins to see, among other things,  if I can find matches with the six bacteria identified by the present analysis. A further step will be to pursue an analogous study for eukaryotic microorganisms and for human proteins (in search for autoantibodies).

 

A leap of faith

A leap of faith

During last summer, I’ve pursued a lot of things. I delivered a speech in Turin, after the screening of the documentary Unrest, about the OMF-funded research on the use of the measure of blood impedance as a possible biomarker for ME/CFS (video, blog post, fig. 1, fig. 2).

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Figure 1. Group photo after the screening of Unrest in Turin, Italy, with the organizer of the event (Caterina Zingale, second from the right) and representatives of two Italian ME/CFS associations.
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Figure 2. Question time after the screening of Unrest. On the screen, a drawing of mine.

Then I flew to London to attend the Invest in ME conference, the annual scientific meeting that gathers researchers from all over the world who shared their latest work about ME/CFS. There I met Linda Tannenbaum, the CEO of the Open Medicine Foundation, whom I had the pleasure to encounter for the first time about a year before in Italy, and I introduced myself to Ronald Davis (fig. 3), the world-famous geneticists turned ME-researcher because of his son’s illness. I presented to him some possible conclusions that can be driven from the experimental results of his study on the electrical impedance of the blood of ME/CFS patients, with the use of an electrical model for the blood sample (R, paragraph 6).

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Figure 3. Talking to Ron Davis about a possible explanation for the increase in electrical impedance in the blood of ME/CFS patients in London, during the last Invest in ME conference (blog post).

In London, I was able to visit the National Gallery and while I was passing by all these artistic treasures without being able to really absorb them, to get an enduring impression that I could bring with me forever, I decided to sit down and to copy one of these masterpieces (I can’t draw for most of the time, and when I improve for a few weeks in summer, I usually have to carefully choose where to put my energies). I sat probably beside one of the least important portraits collected in the museum (Portrait of a young man, Andrea del Sarto, figure below) and I started copying it with a pen. When I finished, the museum was closing, so that I missed all the works by Van Gogh, among many other things.

We were at the beginning of June, I was experiencing my summer improvement, a sort of substantial mitigation of my illness that happens every other summer, on average. But because of these travels, I elicited a two-month worsening of symptoms, during which I had to stop again any mental and physical activity: I just lay down and waited. At the beginning of August, I started thinking and functioning again and I almost immediately decided to quit what was my current project (a 600-page handbook of statistics that I commenced in 2017) and I started studying mathematical modelling of enzymatic reactions (figures 4 and 5).

Cattura.JPG
Figure 4. The plot of the reversible Michaelis-Menten equation for ribulose-phosphate 3-epimerase. The intersection of the surface with the plane is the state of equilibrium of the reaction (the rate of production of X5P is the same as the rate of its transformation into Ru5P) (R).
sa.png
Figure 5. The plot of the concentrations of S, P, ES and E for the transformation of L-tryptophan into N-formylkynurenine by IDO-2. This is a semianalytical solution that I found using the approximation of the Lambert function. I also pursued numerical solutions, of course (R).

I knew that these reactions were described by ordinary differential equations and that I could solve them numerically with the methods that I studied just before I got sick, about 18 years ago. I was interested in the metabolic trap theory by Robert Phair, an OMF-funded researcher. So I downloaded a chapter of one of the most known books of biochemistry and a thesis by a Turkish mathematician on metabolic pathways simulation and I started my journey, working on the floor (I have orthostatic intolerance even when I get better in Summer, so I can’t use a desk, figure 6). I ended up learning the rudiments of this kind of analysis, also thanks to a book by Herbert Sauro and to some suggestions by dr. Phair himself! Some of the notes I wrote in August are collected here.

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Figure 6. In August I was studying mathematical modelling of metabolic pathways, sitting on the floor: because of my orthostatic intolerance, I can’t sit for long, especially when I need to think. You can see the book by Sauro opened in the foreground, the thesis by a Turkish mathematician (red cover), and the handbook of Octave (blue/red cover).

At the beginning of September, I was absorbed by the problem of how to study the behaviour of the steady states of tryptophan metabolism in serotoninergic neurons of midbrain as the parameters of the system change. This kind of analysis is called bifurcation theory and I literally fell in love with it… In figure 6 you can also see a drawing: I was drawing a picture I have been thinking about for the last 20 years. It is a long story, suffice it to say that in 1999, just before my mind faded away for 18 months, I started studying the anatomy of a man who carries a heavy weight on his back (see below). That was my first attempt of communicating what was happening to me, of describing my disease.

Only recently I considered to not represent the weight, which is a more appropriate solution since this is a mysterious disease with no known cause, and I made a draft (the one in figure 2) that I then used as a starting point for the drawing below. I finished this new drawing at the beginning of September, in a motel room of San José, in California, just in time for donating it to Ronald Davis (figures below) when I moved to the US to attend the third Community Symposium at Stanford (see here). In California, many surprising things happened: I met again Linda Tannenbaum and Ronald Davis, and yes, I encountered also Robert Phair! But this is another story…

resilience 2

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In the following pictures, you can see how the drawing evolved. Notably, the figure in the centre changed his face and some part of his anatomy. The three figures are meant to be a representation of the same figure from three different points of view. It is more like a project for a sculpture, a monument that is much deserved by these patients.

At Stanford, I had the chance to be face to face with one of my preferred sculptures ever: The Thinker, by Rodin, in both its version: the model moulded first, on the top of The Gates of Hell, and the big one (crafted later), now considered the iconic symbol of Philosophy, but likely originally meant to be a metaphor for creative thinking (I say that because the original sculpture included in The Gates of Hell is a representation of the Italian poet Dante Alighieri, depicted in the act of imagining his poem).

At the end of September, my mind started fading away again. I knew that would have happened, even though I had an irrational hope that this year would have been different. At that point, I was in Italy and I asked some friends to help me organize a trip to the southern hemisphere, in order to live another summer. It required more time than I would have hoped. I am going to leave from Italy only tomorrow. My goal: Argentina. I have been able to do something, at a highly reduced speed, in October, though. I have developed a model for solar radiation at sea level, in function of the day of the year, of the latitude, and of the distance from the Sun (I have considered the actual elliptic orbit of our planet). The main problem has been the modelling of absorption and of diffusion of radiant energy from our star by the atmosphere, but I solved it. Part of these notes are here, but I want to self-publish the end product, so I keep the rest to myself. In that period, I was also able to find the exact solution of the improper integral known as the Stefan-Boltzmann law, something I tried to do in the summer of 2008, in vain, in one of my recovery-like periods. In figure 6 you can see one of the results of my model for solar radiation: the monochromatic emissive power at sea level in function of the day of the year, for the city of Buenos Aires.

emissive power.png
Figure 7. The monochromatic emissive power of the sun at noon, at sea level, at a latitude of -32° N, in function of the wavelength and of the day of the year. Note that the vertical axis is expressed in W on microns multiplied by square meters.

My intention was to use that model to choose the perfect place where to move in order to have environmental conditions that closely resemble the ones that we have in Rome from June to September (the period in which my improvements happen). I also wanted to quantitatively study the effect of both infrared radiation and ultraviolet radiation on my biology. There are several interesting observations that can be made, but we will discuss these subjects another time, also because I had to quit this analysis given my cognitive deterioration. The video below is a byproduct of the geometric analysis that I had to pursue in order to build my model for solar radiation at sea level.

Dawn and dusk at a latitude of 42 degrees north, during three years of the silent rolling of the Earth on its silken ellipse. Three years of adventures, suffering, joy and death.

So, by November my mind was completely gone and my physical condition (namely orthostatic intolerance and fatigue) had worsened a lot. This year I have been able to try amphetamines: I had to go from Rome to Switzerland to buy them (they are restricted drugs that can’t be sold in Italy and can’t be shipped to Italy either). One night I felt good enough to take a train to Milan and then to take another transport to the drug store. And back. I managed to do the travel but I pushed my body too far and I had to spend the following month in bed, 22 hours a day, with an even worse mental deterioration. It is like having a brain injury. Amphetamines have been useless in my case, despite two studies on their potential beneficial effect in ME/CFS.

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Right now, I am collecting all the books and the papers that I need with me in Argentina (figure above), in case I will improve enough to study again. But what am I going to work on?

  1. I want to finish my model of solar radiation, with some notes on the effect of infrared radiation, ultraviolet radiation and length of the day on the immune system. There is a mathematical model published recently that links the length of the day to the power of the innate immune system, and I want to write a code that calculates the relative activity of the innate immunity in function of latitude and day of the year. I would like to self- publish it as a booklet.
  2. I want to finish my handbook of statistics.
  3. I need to correct a paper submitted for publication (it has been accepted, but some corrections have been required).
  4. I want to deepen my understanding of the bifurcation theory for metabolic pathways and to continue studying tryptophan metabolism with this new knowledge.
  5. I want to complete my work on autoantibodies in ME/CFS (see this blog post) and to submit it to a journal. I have been working on that for a while, inventing new methods for the quantitive study of autoimmunity by molecular mimicry.

Should I improve again in Argentina, several avenues can be followed in order to understand the reason why summer causes this amelioration in my own case. I have many ideas and I’ll hopefully write about that in the future. Of course, I also want to read all the new research papers I have missed in the last months. I will bring with me my handbook of anatomy for artists because I hope to be able to draw again, and I won’t miss this opportunity to leave some other handcrafted images behind me for posterity, that can’t care less, obviously! I would really like to finish the drawing below because I feel that in this draft I have found a truly elegant (and mechanically correct) solution for the hip joint of a female robot.QR-A_000026

Now I am useless, my mind doesn’t work and I am housebound. I can’t read, I can’t draw, I can’t do calculations, I can’t do coding, I can’t cook… This has been the quality of my life for most of the last 20 years. This is a huge waste: I would have used these years to perform beautiful and useful calculations and to pursue art. I would really make people understand how tragic this disease is in its cognitive symptoms, what we lose because of it. This is, in fact, the reason behind this blog post: I wanted to give an idea of what I can do when I feel better, and of what I would have done if there had been a cure.

I have lost most of my adult life, but I will never accept to waste a day without fighting back.