What causes Jarisch-Herxheimer reactions ?

[Guest guest]

Hello,

I am pretty new to the group, mostly a lurker as I have no real scientific knowledge or understanding that will help others (just a hungry mind!).

I wanted to understand what causes Jarisch-Herxheimer reactions, especially since my doctor had been trying antibiotic treatments to see if it will improve my CFS/ME condition (no active infection has been found, but tests have not been as thorough as I would like). I tried Cipro and saw improvement for a few weeks, then a slide back down (along with many new joint aches!). Then came Minocylcine, which gave me severe reactions after a few days, pronounced drops in blood pressure, increased malaise, weakness, etc. After 2 months of Mino, I stopped as I await further testing.

I searched the Web for scientific studies on JH and was amazed that little has really been published on its physiological causes or its process. I did find the following article published in 1992 in the Journal of Antimicrobial Chemotherapy by E. : "New insights into the pathophysiology of the Jarisch-Herxheimer reaction" : http://jac.oxfordjournals.org/cgi/reprint/29/6/613

Here are some points made in the article which seem significant to me :

· JH-R is a passing worsening of symptoms after an adequate dose of an appropriate antibiotic. It consists of a sudden rise followed by a gradual fall in body temperature, a transient increase followed by a more profound drop in blood pressure and worsening of constitutional symptoms (can be life-threatening).

· The mediators causing the reaction have not yet been clearly identified.

· In one study with syphilitic patients, JHR was noted in the absence of endotoxins (which had been thought to mediate JHR) : other arguments are also given against the endotoxin explanation.

· Similarities are seen between JRH and the results of administering Tumor Necrosis Factor (TNF) to humans. The author hypothesises that it is the orchestrated release of cytokines that cause the immune, physiologic and metabolic effects of infection.

And my questions :

If the cytokine-storm explanation is correct, can it explain why someone would experience severe symptoms for months on end to antibiotics ?

If there is no drop in blood pressure, can it still be JRH ?

What about claims that JHR is caused by toxins released by dying organisms? This seems like one of those explanations which we can readily visualize, those masses of dying organisms causing a temporary flare, while en route we are getting well. Very seductive reasoning but is it accurate?

Carole