Reactivation

[modabberf at who.ch]

Dear All,

That trauma may produce a skin lesion in an infected individual has been
documented.  The picture by Behin which appeared in TDR's 11th program report,
91-92, of a patient with a lesion on the foot was in fact a case of foot injury
which developed into a CL lesion.  This was a co-infection case of leishmaniasis
and HIV.  However, the Lausanne group (Mauel et al ) showed many years ago that
a DTH reaction induced by an unrelated antigen at the site of a CL lesion,
enhanced recovery of CL in guinea pigs  (now we may say due to local effect of
IFN-g production).  If this is true, then the reaction produced by leishmanin
reaction is less likely to lead to a full blown leishmanial lesion - unless if
we assume that the DTH reaction subsides but the infiltrating cells, some with
parasites,  persist to proceed toward a lesion formation.

I would like to know if parasite was ever isolated from the lesion produced by
the leishmanin skin test?.  Otherwise, some highly reactive individuals (
possibly due to deep involvement with leishmaniasis, such as myself) could
produce a strong reaction against leishmanin with a lesion that lasts several
weeks and even leaves a little scar for a long time.      

Regards,
Farrokh Modabber
Please note my correct address <modabberf at who.ch>  the old one <modabber at who.ch>
does not work any more.
Thanks,


____________________Reply Separator____________________
Subject:    Reactivation 
Author: "felix j. tapia" <ftapia at telcel.net.ve>
Date:       27-Jan-1999 20:06

Dear Bruce, Jeffrey and leishmaniacs of the World,

The K÷ebner phenomenon or ability of traumatized, uninvolved skin to
develop disease, is very common in skin diseases such as psoriasis,
vitiligo and leishmaniasis.

In leishmaniasis, the interested persons must read the key articles by
the groups of Sergio Coutinho (Brazil) and Bruno Travi (Colombia).

Trauma, including the application site of a Montenegro skin test, may
activates the parasite and/or immunological memory causing a chronic
immune response with associated tissue damage.  Other factors may be
involved, such as vasodilator peptides (among other, Maxadilan present
in the saliva of Lutzomyia sp.).  The production of TGF-beta in either
traumatized skin or cutaneous sites of reoccurring sandfly bites may
inhibits IFN-gamma activity and antigen presentation by macrophages, and
thus contribute to mmunopathology.
Pure, but interesting, speculation.

Felix J. Tapia

--
----------------------------------------
Felix J. Tapia
ftapia at telcel.net.ve / tapiaf at camelot.rect.ucv.ve
Lab. Biologfa Molecular, Instituto de Biomedicina
Universidad Central de Venezuela
Apartado 4043, Caracas 1010A, Venezuela
Telf. (582)838277 (directo/fax), (582)8625326, Ext. 4232
Beeper 7310711, clave 00442
Fax (582)8611258

"Any sufficiently advanced technology is indistinguishable from magic"
Arthur C. Clarke