(The) effect of prednisolone on tuberculin reaction in guinea pigs
Stoerk(1950) reported that the administration of cortisone or ACTH to guinea
pigs, vaccinated with BCG, will attenuate or block the tuberculin reaction. Derbes
et al(1950) and Cummings et al(1952) confirmed this.
Tuberculin skin reaction is the prototype of delayed hypersensitivity and contact
dermatitis, homograft rejection phenomena and autoimmune disease are a kind of
delayed type of hypersensitivity.
The present studies are undertaken in an attempt to identify the mechanism of
effects of prednisolone on tuberculin reaction.
Material and Method
Forty-five albino guinea pigs, each weighting 400 to 600 gm, were injected with
1cc(20mg/cc) of BCG intraperitoneally. After 3 weeks, a PPD skin test was done and
the animals which showed a positive reaction were for the experiment and divided
into the following three groups:
1) Control group 2) Predisolone treated group was subdivided into those having
doses of 1mg/kg and 4mg/kg.
Before administration of prednisolone, WBC, WBC differential count and antibody
titer to tuberculosis were checked and compared with the results after
administration of the drug. The prednisolone was administered per oral route,
daily, for 8 weeks. PPD skin test was done once every week and the size of
induration was read 48 hours after the test done.
When the tuberculin reaction was markedly suppressed with prednisolone, passive
transfer of tuberculin hypersensitivity with viable leukocytes was tried and a
histological examination was done with routine hematoxylin-Eosin staining
Result and Discussion
The Decreased tuberculin skin reaction occurred 1 week after administration and
the marked inhibition of tuberculin skin reaction occurred 5 weeks after
The group treated with prednisolone, dosage of 4mg/kg, was much more inhibited
than the group having doses of 1mg/kg for 4 weeks. From 5 weeks after
administration of prednisolone, there was no difference between the 2 groups.
The recovery from tuberculin skin reaction occurred within 48 hours after
discontinuing the administration of prednisolone.
When the tuberculin skin reaction was markedly suppressed, antibodies to
tuberculosis were not decreased accordingly and the leukocytes derived from the
guinea pigs could transfer immunity to normal guinea pigs, even though with
depressed skin reaction.
Lymphopenia and eosinopenia occurred after the prednisolone administration and
histologic examination of the skin tested showed a marked decrease of lymphocytes
in the area.
Regarding the mechanism of action on the tuberculin reaction, Germuth et al(1952)
stated that the same mechanism was involved in the suppression of nonspecific
inflammatory reactions. Leathy & Morgan(1952) reported that cytotoxic action of PPD
was inhibited by pretreatment of prednisolone. Wasserman(1967) also reported
prednisolone inhibited the synthosis of DNA and RNA, and suppressed the mitosis of
lymphocytes occurring after contact with antigen.
The mechanism of prednisolone in inhibiting tuberculin reaction is still unknown
and requires further study.