Streptococcal serotypes in patients with guttate psoriasis

Group A streptococcal antigen-specific T lymphocytes in guttate psoriatic lesions

A strong association exists between guttate psoriasis and group A, beta-haemolytic streptococcal infections. To demonstrate the presence of streptococcal-specific T cells in psoriatic skin, T-cell lines (TLs) were established from biopsies of lesions from five patients with guttate psoriasis, and compared with TLs from five patients with eczema, five with lichen planus, two with pityriasis rosea and three with nickel contact dermatitis. TLs from purified protein derivative (PPD)-induced delayed hypersensitivity sites in three normal individuals were also studied. All five of the psoriatic TLs responded in a proliferation assay to heat-killed isolates of group A streptococci, compared with only one eczema, two lichen planus and one pityriasis rosea. The response of one nickel contact dermatitis and two PPD TLs to group A streptococci was markedly less than to nickel and PPD, respectively. One of the psoriatic TLs was cloned in the presence of type 5 streptococcal M protein. The nine clones obtained were all CD3+, CD4+, CD45RO+, TCR alpha, beta+, gamma, delta-. However, they were all unreactive with antibodies to TCR V beta 5, 6, 8 or 12. Eight of the nine clones reacted, to a varying extent, to one or two of three preparations of group A streptococci expressing different M proteins. The streptococcal response of four consistently reactive clones from this patient was HLA-DR-restricted and inhibited by anti-HLA-DR antibody in a dose-dependent manner. On stimulation these four clones secreted high levels of gamma-interferon and detectable levels of IL-2, IL-10 and granulocyte/macrophage colony stimulating factor (GM-CSF) depending upon the nature of the stimulus, but no IL-4 or TNF-alpha production was detected. This study has demonstrated, for the first time, that T lymphocytes specific for group A streptococcal antigens can be consistently isolated from guttate psoriatic lesions. The role of streptococcal-specific T cells in the pathogenesis of psoriasis remains to be determined.

Immunoblotting of streptococcal antigens in guttate psoriasis

Guttate psoriasis may be precipitated by acute streptococcal infection, usually of the upper respiratory tract. We have studied the immune response to streptococci in 26 patients presenting with a first or recurrent episode of acute guttate psoriasis (AGP), using immunoblotting. Eighteen of 26 patients studied had a demonstrable response to a wide range of streptococcal antigens using this approach, compared with 14 of 26 patients who demonstrated a response using more conventional antistreptococcal antibody tests. Patients with AGP had a significantly higher antibody detection score using immunoblotting than did control subjects (P < 0.005). We conclude that immunoblotting is a useful technique in studying this condition and may be of benefit in exploring the immunopathogenesis of AGP.

A therapeutic trial of the use of penicillin V or erythromycin with or without rifampin in the treatment of psoriasis

BACKGROUND

After the publication of an uncontrolled trial of nine patients with streptococcus-associated psoriasis who appeared to benefit from a course of oral penicillin or erythromycin with the addition of rifampin in the last 5 days, we wished to confirm or refute the validity of this observation.

OBJECTIVE

Our purpose was to confirm the effectiveness of antibiotics in the treatment of streptococcus-associated psoriasis.

METHODS

Twenty patients were placed randomly into two groups. One group was given penicillin or erythromycin for 14 days with a placebo added during the last 5 of the 14 days. The other group received the same medication with the addition of rifampin in the last 5 days.

RESULTS

Although all the patients studied met the criteria of the reported preliminary study, we were unable to detect any evidence of improvement in their psoriasis.

CONCLUSION

There was no apparent benefit for patients with streptococcus-associated psoriasis from a course of oral penicillin or erythromycin with the addition of rifampin in the last 5 days in a 14-day trial.