Anergy testing in patients with head and neck cancer.

Patients with head and neck cancer were found to be deficient in were not clear [correction] Possible explanations include a change in T-lymphocyte numbers, particularly the helper/suppressor T-cell ratio, with the cause of this change still unknown. Tumor immunosuppressing factors and cancer-induced immunosuppression are proposed to be such causes. The deficiency of T cells resulted in an impaired cell-mediated immune response (CMIR), which lowered the host resistance, such facilitating the tumor to spread. As the CMIR can be evaluated by delayed hypersensitivity skin testing (= anergy screen), the objective of this study was to compare the CMIR function of patients with head and neck cancer to a non-cancer control group using this anergy screen. The study group consisted of 20 patients (17 males, 3 females, age range 10-76 years) with head and neck cancer, which were anti-HIV negative and had not received any therapy yet. The control group consisted of another 20 persons (17 males, 3 females, age range 21-72 years) without any cancer and who were also anti-HIV negative. Exclusion criteria were (1) eczema or skin disease in the area to be tested, (2) having received oral prednisolone within the last week and (3) an anti-HIV positive immune status. The antigens used in this study consisted of PPD (5 IU), tetanus toxoid (TT) (0.8 LF/ml and 1.6 LF/ml, Candida albicans (20 PNU/ ml and 200 PNU/ml), mumps-measles-rubella (MMR) vaccine (1:10 v/v and 1:5 v/v). The test was done by intradermal injection of 0.1 ml of each antigen. The anergy screen was considered positive when the test resulted in an erythema or induration larger than 5 mm at 72 hours after the injection. Complete anergy was diagnosed when there was no skin reaction at all, partial anergy when only 1 antigen tested positive and no anergy when there were positive skin reactions to two or more antigens. In the study group, 9 (45%) patients were diagnosed with complete anergy, 11 (55%) with partial anergy and none with no anergy, while in the control group, none were complete anergic, 3 (15%) were partially anergic and 17 (85%) had no anergy. There was a statistically significant difference (p < 0.01) between these two groups. In conclusion, patients with head and neck cancer seemed to have an impaired CMIR, with at least the partial anergy being statistical significantly different compared to the non-cancer group.

Recombinant American cockroach component, Per a 1, reactive to IgE of allergic Thai patients.

Twelve similar recombinant Per a 1 clones were produced from an American cockroach (CR) cDNA library. The nucleotide sequence of a representative cline, i.e. clone A6, contained 579 base pairs (bp) and a 372 bp open reading frame (2-373) encoding 124 amino acids. A stop codon was found at position 374-376 followed by a 3' end untranslated region with an AATAAA polyadenylation signal and a poly (A) tail. The estimated molecular mass of the 24 amino acid residue protein was 13.8 kDa, with a predicted isoelectric point value of 4.74. Cysteine or N-linked glycosylation was not found. The deduced amino acid sequence of the A6 revealed 84.68-95.97% identity to other previously reported Per a 1 clones and 65.87-69.60% homology to the previously reported Bla g 1 clones. However, while previously reported Per a 1 clones showed homology to ANG12, a precursor protein in the midgut of the female Anopheles gambiae secreted after the blood meal, the A6 DNA sequence was found to have homology (37.1%) to DNA of G2, a putative protein in the midgut of Aedes aegypti (AY 050565). The deduced amino acid sequence of A6 contained a mitochondrial energy transfer protein signature, phosphorylation sites for the cAMP-and cGMP-dependent protein kinase C and casein kinase II. Hydrophobic and hydrophilic characteristics of the A6 deduced peptide indicated that it was a transmembrane protein. This is the first report that Per a 1 is a transmembrane protein. The deduced amino acid sequence of the A6, which contained the sequence LIRSLFGLP, differed in one amino acid from two previously reported epitopes, i.e. LIRALFGL and IRSWFGLP, of Per a 1.0104 which bound 80% and 100%, respectively, to IgE of the allergic patients tested. The A6 DNA sequence was deposited in the GenBank (Accession number AY 259514) and has been designated Per a 1.0105. The A6 expressed protein bound to monoclonal antibodies (MAb 3C2) specific to American cockroach and also bound to IgE of all (100%) of the 20 allergic Thai patients.