A "case control" study on the role of HLA DR4 in severe periodontitis and rapidly progressive periodontitis - Identification of types and subtypes using molecular biology (PCR.SSO)
Jj. Bonfil et al., A "case control" study on the role of HLA DR4 in severe periodontitis and rapidly progressive periodontitis - Identification of types and subtypes using molecular biology (PCR.SSO), J CLIN PER, 26(2), 1999, pp. 77-84
HLA DR4 antigens have been considered as a risk factor in periodontal disea
se. The aim of this "case control'' study was to verify and to provide full
er clarification of such data. "Cases" or patients had to be aged between 2
0 and 48 years. They presented at least 5 sites spread over several teeth w
ith an attachment loss equal or greater than 6 mm, and 10 sites spread over
several teeth with periodontal pockets equal to or greater than 5 mm. Veri
fication with a WHO probe showed an individual CPITN score of 4. Moreover,
subjects whose average CPITN score for the 6 sextants was less than 3 were
excluded from the study. Among these "severe periodontitis" patients, a sub
group was distinguished composed of subjects aged 20-35 years who presented
, in accordance with the cases by Katz and co-workers, 5 or more teeth show
ing pocket depths of 6 mm or more. The dental chartings of these subjects s
howed an attachment loss of more than 3 mm on certain teeth over an inter-e
xam period of 1-3 years. They all displayed obvious loss of bony support in
the affected sites. This constituted the "rapidly progressive periodontiti
s" subgroup. The "controls" were all over 20 years of age, and it was clini
cically verified that they were free of periodontal disease. There were 48
"cases" and 55 "controls". HLA typing of patients and controls was performe
d using "sequence oligoprobe hybridization after polymerase chain reaction"
in accordance with the 11(th) International Workshop. This method allowed
the detection of DR4 alleles as well as DR4 subtypes. The ethno-geographic
origin of the subjects, considered as a confounding variable, was neutraliz
ed by stratified analysis. Subtypes 0401, 0404, 0405 and 0408 tended to be
more frequent (p = 0.08) in the cases (Severe Periodontitis). Focusing on a
nalysis of "rapidly progressive periodontitis" in subjects aged 20-35 years
, a very significant Mantel-Haenszel chi(2) was obtained (p = 0.0058) which
led to a Mantel-Haenszel standardized odds ratio (OR) equal to 17. The 95%
confidence interval was 1.03<O.R.<180.10. In conclusion, this supports pre
vious reports and gives further clarification: in particular subtypes 0401,
0404, 0405 and 0408 can be considered as a risk factor for "rapidly progre
ssive periodontitis". It should be noted that these determinants have been
implicated in rheumatoid arthritis.