Reactivity of in vitro activated human T lymphocytes to p-phenylenediamine and related substances.
BACKGROUND
Patch tests to p-phenylenediamine (PPD) and related substances often show concurrent reactions that can be attributed to separate sensitization or cross-reactivity.


OBJECTIVE
In order to understand the health risks associated with cross-reactivity, we studied cross-reactivity of eight chemicals in vitro by measurement of T-cell proliferation of peripheral blood mononuclear cells (PBMC), T-cell lines (TCL), and T-cell clones (TCC) of subjects with a positive patch test result to PPD.


METHODS
We studied PBMC from 13 patients and were able to generate TCL from seven and TCC from four patients. Their proliferative responses to the chemicals were estimated.


RESULTS
Concurrent reactions to these compounds on the polyclonal and monoclonal level were found. A restricted T-cell receptor (TCR) Vbeta16-usage was observed (5/8 clones). A detailed analysis of 34 TCL showed broad cross-reactivity (64.7%) between PPD, p-toluenediamine, Bandrowski's Base, and p-aminoazobenzene. More restricted patterns were found in 8.8%, which responded only to compounds with two or three benzene rings, whereas 26.5% of the clones reacted specifically only to one compound.


CONCLUSIONS
More than 60% of the clones showed a broad cross-reactivity pattern. Hence, clinically observed cross-reactivity between different para-amino compounds can be based on a TCR recognizing similar epitopes of these compounds with low specificity.
Department of Dermatology and Allergology, University Hospital of the RWTH Aachen, 52074 Aachen, Germany.
Claudia
C
Skazik
Silke
S
Grannemann
Liane
L
Wilbers
Hans F
HF
Merk
Pieter-Jan
PJ
Coenraads
Sebastian
S
Breuer
Brunhilde
B
Blömeke
D002460:Cell Line / Q000187:drug effects; D049109:Cell Proliferation / Q000187:drug effects; D002999:Clone Cells / Q000187:drug effects; D017449:Dermatitis, Allergic Contact / Q000276:immunology*; D004342:Drug Hypersensitivity / Q000276:immunology; D004347:Drug Interactions; D006801:Humans; D006968:Hypersensitivity, Delayed / Q000139:chemically induced / Q000276:immunology; D066298:In Vitro Techniques; D008213:Lymphocyte Activation / Q000187:drug effects* / Q000276:immunology; D010328:Patch Tests / Q000379:methods; D010655:Phenylenediamines / Q000008:administration & dosage / Q000494:pharmacology* / Q000633:toxicity; D013601:T-Lymphocytes / Q000187:drug effects* / Q000276:immunology; D010128:p-Aminoazobenzene / Q000633:toxicity
D010655:Phenylenediamines; C051597:Bandrowski's base; C007303:2,5-diaminotoluene; D010128:p-Aminoazobenzene; C029728:4-phenylenediamine