Pubmedwhack: Coproagglutinins

by Mike

You may be familiar with the concept of a “Googlewhack”, which in common parlance is a word or phrase that returns exactly one result when typed into Google. Wikipedia claims it must be two words, without quotation marks, and a single word or a phrase in quotation marks is not a “Googlewhack” but is a “Googlewhackblatt” or some other hair-splitting neologism. But the word was invented and given that definition a decade ago, and I think the original definition is no longer practical.

So a Pubmedwhack would be a phrase that, when typed into Pubmed, the indispensible bioscience citation database, gives exactly one result. Like “vampyric” (1), or “great blue heron embryos” (2).

One example from immunology is “coproagglutinins”. Search for that and all you get is a 1951 paper (3) (subscription required) from the U.S. Army’s 406th Medical General Laboratory, which was headquartered in Tokyo.


In this study they were trying to diagnose which type of organism was causing bloody diarrhea, by looking for antibodies in the diarrhea itself. Anti-Shigella antibodies suggest that it’s a Shigella infection. Anti-Corynebacterium antibodies suggest diphtheria. And so on. “Copro-” is, of course, the prefix referring to feces, as in “coprolite” (4). The word “coproantibodies” is found in a few dozen titles and abstracts, including 20 or so from the 21st century. So it’s not a ridiculous technique. But this is the only paper to combine the new (as of 1951) concept of antibodies measured in feces, with the old (as of a few years later) word “agglutinins”.

To detect antibodies at this time, we had moved beyond complement fixation and amboceptors and whatnot. People doing serological tests could mix serum, or in this case fecal extracts, with a sample of Shigella paradysenteriae. If the extract contained antibodies specific for that bacteria, they would bind each other and form aggregates, making the solution cloudy.

That’s agglutination. You do it to detect agglutinins, which are the kind of antibody that agglutinates. Although agglutinins, like amboceptors, are best described as simply “antibodies”.

Now we have various other techniques for detecting antibodies. So to call them “agglutinins” just because you’re using agglutination to detect them adds confusion.

The word “agglutinins” is still used in the 21st century, to describe the antibodies of certain autoimmune diseases, as in this Blood editorial (5). We all make some antibodies against our own red blood cells. With too many anti-RBC antibodies, this can lead to the RBCs aggregating and being destroyed by complement. Especially in cold weather and in the extremities, hence the name “cold agglutinins”.

Science is not aware of any cold coproagglutinins.

Another way to tell Salmonella from Shigella (click for source)

Another way to tell Salmonella from Shigella (click for source)

1. Almond BR (2007). Monstrous infants and vampyric mothers in Bram Stoker’s “Dracula”. Int J Psychoanal 88:219-235.

2. Hart LE (1991). Dioxin contamination and growth and development in great blue heron embryos. J Toxicol Environ Health 32:331-344.

3. Barksdale WL, Ghoda A, Okabe K (1951). Coproagglutinins in ulcerative colitis. J Inf Dis 89:47-51.

4. Steve (2010). Coprolites: A few words on prehistoric turds., accessed November 1, 2013.

5. Stone MJ (2008). Heating up cold agglutinins. Blood 116:3119-3120.