Large-scale DNA-based typing of HLA-A and HLA-B at low resolution is highly accurate specific and reliable

DNA-based typing of HLA class I alleles of the HLA-A and HLA-B loci using sequence-specific oligonucleotide primers and/or probes has been used for the large-scale typing of individuals for the National Marrow Donor Program unrelated donor registry. Typing was performed by 16 laboratories at a low level of resolution (e.g. A*01, B*07). The results of blinded quality control analysis for the first 12 months of the project show the typing to be highly accurate, specific and reliable. The total error rate based on 11,545 HLA-A and 11,428 HLA-B assignments was 1.1% for HLA-A and 1.9% for HLA-B. This level of accuracy is particularly remarkable because the quality control samples could not be distinguished from 64,180 donor samples tested at the same time by the laboratories.

A new modular chemiluminescence immunoassay analyser evaluated

Thyrotropin (TSH), free thyroxine (fT4) and testosterone assays have been used as a probe to evaluate the performances of a new modular chemiluminescence (CL) immunoassay analyser, the Abbott Architect 2000. The evaluation was run in parallel on other systems that use CL as the detection reaction: DPC Immulite, Chiron Diagnostics ACS-180 and ACS Centaur (TSH functional sensitivity only). TSH functional sensitivity was 0.0012, 0.009, 0.033 and 0.039 mU/I for the Architect, Immulite, ACS Centaur and ACS-180, respectively. Testosterone functional sensitivity was 0.38, 3.7 and 2.0 nmol/l for Architect, Immulite and ACS-180, respectively. Good correlation was obtained between the ACS-180 and Architect for all assays. The Immulite correlation did not agree well with the Architect or ACS-180 for fT4 and testosterone but was in good agreement for TSH. Regarding fT4 and testosterone, equilibrium dialysis and isotopic dilution gas-chromatography mass-spectrometry (GC-MS) respectively were used as reference methods. For both within- and between-run precision, the Architect showed the best reproducibility for all three analytes (CV < 6%).

Lichen planus pemphigoides with IgG autoantibodies to the 180 kd bullous pemphigoid antigen (type XVII collagen)

We describe a 75-year-old patient with pruritic papules on her trunk and extremities, typical of lichen planus, who later experienced subepidermal blisters. These clinical features are consistent with lichen planus pemphigoides. Immunofluorescence of perilesional skin showed linear deposits of C3 along the dermoepidermal junction. Circulating IgG autoantibodies were found to be directed against an epidermal component of the dermoepidermal junction because the patient's serum labeled the epidermal side of 1 mol/L NaCl-split skin. The patient's IgG autoantibodies were directed exclusively against the 180 kd bullous pemphigoid antigen (BPAg2, type XVII collagen) detected in human keratinocyte lysate by Western blot assay. No reactivity was found against the 230 kd bullous pemphigoid antigen, type VII collagen, or the laminin-5 subunits. This study demonstrates that BPAg2 is recognized, not only by bullous pemphigoid sera, but also by lichen planus pemphigoides sera. Our findings attest to the similarity of immunopathology in these two subepidermal blistering skin diseases.

Localized primary cutaneous Mycobacterium kansasii infection in an immunocompromised patient

Mycobacterium Kansasii is a rare primary cutaneous pathogen, most commonly affecting persons exposed to contaminated water, particularly after local trauma. Most patients who present with localized primary cutaneous M kansasii infection are immunocompetent, whereas the majority of patients with disseminated or pulmonary infection are immunocompromised. We describe a primary cutaneous M kansasii infection in an iatrogenically immunosuppressed patient.

Alopecia areata with features of loose anagen hair

A child with alopecia areata (AA) presented initially with clinical features of loose anagen hair (LAH) and had features consistent with LAH on microscopic hair analysis. However, a scalp biopsy specimen demonstrated peribulbar inflammatory infiltrates characteristic of AA. We suggest that AA may mimic LAH clinically and a scalp biopsy may help in making the correct diagnosis.

Granuloma annulare localized to the palms

Granuloma annulare typically affects the hands and the feet, sparing the volar surfaces. A case of granuloma annulare localized to the palms is described.

White superficial onychomycosis of the fingernail caused by Trichophyton rubrum in an immunocompetent patient

White superficial onychomycosis in immunocompetent patients is most commonly due to Trichophyton mentagrophytes, and almost exclusively involves the toenail. We present a unique case of an otherwise healthy patient with white superficial onychomycosis involving the fingernail caused by T. rubrum.

Two roads diverged: interferon alpha/beta- and interleukin 12-mediated pathways in promoting T cell interferon gamma responses during viral infection

Viral infections induce CD8 T cell expansion and interferon (IFN)-gamma production for defense, but the innate cytokines shaping these responses have not been identified. Although interleukin (IL)-12 has the potential to contribute, IL-12-dependent T cell IFN-gamma has not been detected during viral infections. Moreover, certain viruses fail to induce IL-12, and elicit high levels of IFN-alpha/beta to negatively regulate it. The endogenous factors promoting virus-induced T cell IFN-gamma production were defined in studies evaluating CD8 T cell responses during lymphocytic choriomeningitis virus infections of mice. Two divergent supporting pathways were characterized. Under normal conditions of infections, the CD8 T cell IFN-gamma response was dependent on endogenous IFN-alpha/beta effects, but was IL-12 independent. In contrast, in the absence of IFN-alpha/beta functions, an IL-12 response was revealed and substituted an alternative pathway to IFN-gamma. IFN-alpha/beta-mediated effects resulted in enhanced, but the alternative pathway also promoted, resistance to infection. These observations define uniquely important IFN-alpha/beta-controlled pathways shaping T cell responses during viral infections, and demonstrate plasticity of immune responses in accessing divergent innate mechanisms to achieve similar ultimate goals.

Inhibitory effects of combinations of HER-2/neu antibody and chemotherapeutic agents used for treatment of human breast cancers

Previous studies have demonstrated a synergistic interaction between rhuMAb HER2 and the cytotoxic drug cisplatin in human breast and ovarian cancer cells. To define the nature of the interaction between rhuMAb HER2 and other classes of cytotoxic drugs, we applied multiple drug effect/combination index (CI) isobologram analysis to a variety of chemotherapeutic drug/rhuMAb HER2 combinations in vitro. Synergistic interactions at clinically relevant drug concentrations were observed for rhuMAb HER2 in combination with cisplatin (CI=0.48, P=0.003), thiotepa (CI=0.67, P=0.0008), and etoposide (CI=0.54, P=0.0003). Additive cytotoxic effects were observed with rhuMAb HER2 plus doxorubicin (CI=1.16, P=0.13), paclitaxel (CI=0.91, P=0.21), methotrexate (CI=1.15, P=0.28), and vinblastine (CI=1.09, P=0.26). One drug, 5-fluorouracil, was found to be antagonistic with rhuMAb HER2 in vitro (CI=2.87, P=0.0001). In vivo drug/rhuMAb HER2 studies were conducted with HER-2/neu-transfected, MCF7 human breast cancer xenografts in athymic mice. Combinations of rhuMAb HER2 plus cyclophosphamide, doxorubicin, paclitaxel, methotrexate, etoposide, and vinblastine in vivo resulted in a significant reduction in xenograft volume compared to chemotherapy alone (P<0.05). Xenografts treated with rhuMAb HER2 plus 5-fluorouracil were not significantly different from 5-fluorouracil alone controls consistent with the subadditive effects observed with this combination in vitro. The synergistic interaction of rhuMAb HER2 with alkylating agents, platinum analogs and topoisomerase II inhibitors, as well as the additive interaction with taxanes, anthracyclines and some antimetabolites in HER-2/neu-overexpressing breast cancer cells demonstrates that these are rational combinations to test in human clinical trials.

Phosphodiesterase activity in intrapulmonary arteries and veins of perinatal lambs

The transition from fetal to newborn life is marked by a reduction in pulmonary vascular tone mediated by the intracellular second messengers, cGMP and cAMP. We have compared the rates of phosphodiesterase (PDE)-catalyzed hydrolysis of cGMP and cAMP in intrapulmonary vessels of fetal (146 +/- 2 days gestation) and newborn (3-7-day-old) lambs, each n = 6. Lung vessels of second to sixth generations were dissected and cytosol was prepared by differential centrifugation. PDE activity in cytosol was determined by radiometric assay of the hydrolysis of exogenous nucleotides at 30 degrees C for 10 min. Rates of hydrolysis (pmol/min/mg protein) of cGMP were 225 +/- 38 in fetal arteries and different from 151 +/- 7 in veins. In newborn vessels, the rates were 155 +/- 49 and 63 +/- 13 in arteries and veins, respectively. Rates of cAMP hydrolysis by the fetus were 80 +/- 11 in arteries and 45 +/- 16 veins. In newborn lambs the rates were 69 +/- 10 in arteries and different from 18 +/- 4 in veins. Inhibition of PDE activity by zaprinast, a cGMP-specific PDE inhibitor, and rolipram, a cAMP-specific PDE inhibitor, was more in veins of fetal and newborn lambs. Our data show that rates of hydrolysis of the cyclic nucleotides were faster in fetal vessels than in the newborn. We speculate that this would result in a greater accumulation of the cyclic nucleotides in newborn vessels, particularly the veins, and therefore endow the veins with less vascular tone.

Spores and mycelia in cutaneous chromomycosis

In 2 cases of cutaneous chromomycosis, potassium hydroxide preparations of lesional crust/scale easily revealed characteristic Medlar bodies. However, in both instances mycelia were also demonstrated. This contradicts the prevailing belief that concomitant spores and mycelia are found only in cerebral chromomycosis.

Rapid, automated assay for progesterone on the Abbott AxSYM analyzer

We describe an automated assay for progesterone (P4) in human serum and plasma with the Abbott AxSYM random-access immunoassay analyzer. In this one-step competitive assay, P4 immobilized onto latex microparticles competes with sample P4 for binding to a conjugate of alkaline phosphatase (AP) and anti-P4 antibody. Total CVs ranged from 3.4% to 8.2% in multiple precision studies conducted according to the 20-day NCCLS EP5-T protocol. The detection limit (zero calibrator + 2 SD) was 0.10 microg/L across 36 experiments. Values for diluted samples were 83-116% of expected. Recovery of P4 added to serum specimens was 92-115%. Cross-reactivities with 43 natural and synthetic steroids were 0-6.3%. No significant interference was detected from bilirubin, protein, erythrocytes, hemoglobin, triglycerides, or cholesterol. In a multisite correlation study, AxSYM P4 results compared well with results from a commercial RIA method (n = 1156; r = 0.976; slope = 1.03; y-intercept = 0.04). Assay throughput is >80 tests per hour in batch mode, 60 tests per hour with mixed load list configurations.