Renal function and biopsy findings after 5 years' treatment with low-dose cyclosporin for psoriasis

Renal biopsies were performed in eight patients with chronic plaque psoriasis who had been treated with low-dose cyclosporin (CyA) (range 1–6 mg/kg/day; average dose 3.3 mg/kg/day) for an average period of 5 years. In six of the eight patients biopsies showed features consistent with CyA nephrotoxicity. Tubular atrophy and arteriolar hyalinosis were present in all six, four had an increase in interstitium. and two showed an increased incidence of glomerular obsolescence. Two of the patients showed all of these features, two patients had three features, and the remaining patients had two features. Renal function was assessed by glomerular liltration rate (CFR) and serum creatinine. Both a fall in the GFR and a rise in the serum creatinine correlated with the severity of the features of CyA nephrotoxicity seen on biopsy. However, the best predictor of the biopsy findings was a failure of renal function to show significant improvement when CyA was discontinued for a month.
CyA has been discontinued in two of the eight patients who had the most severe features of CyA nephrotoxicity on renal biopsy. In both patients there has been improvement of renal function after 1 year of foliow-up.     

Differential T-cell reactivity to the round and oval forms of Pityrosporum in the skin of patients with psoriasis

Pityrosporum yeasts have been implicated as a trigger for the initiation of scalp lesions in psoriasis. To determine whether Pityrosporum-reactive T cells are present in lesional psoriatic skin. T-cell lines (TCL) were cultured from the scalps of nine patients with psoriasis and seven with alopecia areata (disease controls), and from non-scalp lesions from six of the psoriatic patients. The psoriatic skin TCL were stained for CD3, CD4, CD8 and TCR αβ expression and tested in a proliferation assay with Candida albicans and purified protein derivative (PPD), and cytoplasmic and cell-wall extracts of P. ovale (oval) and P.orbiculare (round). The proliferative responses of corresponding peripheral blood mononuclear cells (PBMC) were also determined. All the PBMC samples responded to the Pityrosporum extracts to variable extents, but no significant difference in the response of the group to the two different forms of yeast was observed. The response was mediated by CD4⁺ T cells and inhibited by the addition of anti-HLA-DR antibody. In addition, all nine psoriatic scalp TCL, which were predominately CD3⁺, CD4⁺ TCR αβ⁺, responded to the cytoplasmic, and five of nine TCL to the cell-wall extract of P. orbiculare. In contrast, only three of the nine TCL proliferated to either extract of P. ovale. This difference was significant for both the cytoplasmic (P < 0.01) and cell wall (P = 0.01) extracts. Similarly, the TCL cultured from non-scalp psoriatic lesions also showed a more marked response to the P. orbiculare extracts (P = 0.05). Furthermore, four of seven and two of seven scalp TCL from lesions of alopecia areata responded to the P. orbiculare and P. ovale extracts, respectively; these responses did not differ significantly from those of the psoriatic scalp TCL. None of the skin TCL responded to either Candida albicans or PPD. These findings demonstrate that T cells with differential reactivity to the round and oval forms of Pityrosporum are present in, but are not specific for, psoriatic skin lesions. A role for these cells in the pathogenesis of psoriasis remains speculative.     

T lymphocytes in lesional skin of patients with dermatitis herpetiformis

Ten patients with dermatitis herpetiformis had biopsies taken from involved skin.Monoclonal antibodies and the avidin-biotin peroxidase staining technique were used to stain for T cells and Langerhans cells in skin sections. A significant increase in the number of CD3-positive T cells was observed in the upper dermis of involved compared with uninvolved skin (P<0.0005). Most of the T cells in involved skin were CD45RO-positive memory cells; CD4-positive T cells exceeded the number of CD8-positive T cells by a ratio of 4:1. In addition, CD1a-positive dendritic cells were observed within the clumps of T cells in involved dermis in nine of the 10 patients, but were absent from the dermis of uninvolved skin. Double immunofluorescent staining demonstrated that approximately 20–40% of the CD3-positive T cells were activated, and expressed the HLA-DR antigen. These findings suggest that activated T cells are involved in the pathogenesis of dermatitis herpetiformis skin lesions.