Searching For A Comprehensive Diagnostic List
Foundational, Complicated, Limited
It’s Foundational
The first step to searching for the available scientific research on a particular autoimmune disorder is to define search terms. This is why my starting point was to compile a comprehensive diagnostic list of autoimmune disorders. This is the foundation—the most basic parameters to use to find the available research on each diagnosis. Get this step wrong, and it can have knock-on effects for every subsequent investigation. Simply put, it’s hard to find the relevant research on autoimmune disorders if you’re searching for the wrong name(s). It’s hard to draw connections between autoimmune disorders if your list is missing a crucial diagnosis. My first stop for a comprehensive list of autoimmune disorders was my trusty go-to, the Johns Hopkins Medicine website. Johns Hopkins notes that a definitive list is difficult because autoimmune diseases
can be challenging to define. Scholars may disagree on the criteria that need to be fulfilled to consider a disease "autoimmune" (i.e, caused by autoimmune mechanisms).
are clinically heterogenous, with numerous subtypes and variants. For example, in multiple sclerosis one could distinguish the primary progressive from the relapsing-remitting forms. In thyroiditis one could distinguish the juvenile, the classic, and the form occurring in older persons (known as idiopathic mixedema). Should the different subtypes be considered different diseases or should they be combined under a single name? As always, definition is critical. Changing how a disease is defined can drastically influence its prevalence.
require a vast breadth of knowledge. In order to make a comprehensive list of autoimmune diseases, there has to be somebody who is familiar with all of them and their numerous clinical variances. Quite a difficult task.
Johns Hopkins lists, and links, to two organizations that have developed diagnostic lists: The Autoimmune Association list and the Global Autoimmune Institute list. I thought, “Great! Problem solved. Copy, paste, compare lists, cite, done.”
Nope.
It’s Complicated
I was expecting differences in naming conventions between the two lists—perhaps some confusion as to which alphabetical letter a given diagnosis belongs under based on slight variations in names. I was expecting minor differences in included diagnoses. What I was not expecting was the significant divergence of distinct diagnoses between the two lists. When I saw that the two lists were divergent enough to require a Legend that visually illustrates commonality and differences, I started thinking more critically about whether these two lists included diagnoses I had encountered professionally. There were a small number of entries that I added based on physician differentials or National Institutes of Health research studies. My goal with my list of autoimmune diagnoses is to err on the side of inclusivity and expansiveness without being so broad as to become meaningless. I have yet to determine what inclusion criteria is needed to make additions to the list, but when I do I will publish how I arrived at the inclusion criteria in order to achieve full transparency. In thinking about my own inclusion criteria, I went back to check the inclusion criteria of my original sources. The Autoimmune Association doesn’t specify how their list was compiled. The Global Autoimmune Institute reports at the beginning of their list
This A-Z list and basic information about each recognized autoimmune disease were compiled and written by our dedicated research team at the Global Autoimmune Institute.
For research nerds like me, I would love to see lists like these prefaced by their inclusion criteria.
It’s Limited
Medicine is messy. Science is …a little less messy. Unlike the art of medicine, scientific results are reproducible, or disprovable, over time. The process of compiling this list of autoimmune disorders has driven home for me how, on the most basic level, autoimmune disorders lack a coherent, science-based lexicon and taxonomy. I only used two lists as my source material. I can only imagine how divergent a multitude of lists would be. Without a common understanding of which diagnoses should be included on a comprehensive list, it’s tragic but predictable, that people who are suffering from symptoms of autoimmune disorders search for years for an accurate diagnosis. That has to change. In this newsletter, I’ll explore how different, yet reputable, sources characterize individual autoimmune disorders. I’ll work to provide useful categories and information for patients and their support persons who are suffering from autoimmune symptoms, but are struggling with what diagnoses to discuss, what testing to discuss, what medications to discuss, even what specialist to see, with their primary care providers. I look forward to using the publicly available research to try to build and share a better understanding.