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1.
Phys Rev Lett ; 131(21): 212501, 2023 Nov 24.
Article in English | MEDLINE | ID: mdl-38072612

ABSTRACT

The cluster structure of the neutron-rich isotope ^{10}Be has been probed via the (p,pα) reaction at 150 MeV/nucleon in inverse kinematics and in quasifree conditions. The populated states of ^{6}He residues were investigated through missing mass spectroscopy. The triple differential cross section for the ground-state transition was extracted for quasifree angle pairs (θ_{p},θ_{α}) and compared to distorted-wave impulse approximation reaction calculations performed in a microscopic framework using successively the Tohsaki-Horiuchi-Schuck-Röpke product wave function and the wave function deduced from antisymmetrized molecular dynamics calculations. The remarkable agreement between calculated and measured cross sections in both shape and magnitude validates the molecular structure description of the ^{10}Be ground-state, configured as an α-α core with two valence neutrons occupying π-type molecular orbitals.

2.
Phys Rev Lett ; 125(12): 122501, 2020 Sep 18.
Article in English | MEDLINE | ID: mdl-33016755

ABSTRACT

We performed the first direct mass measurements of neutron-rich scandium, titanium, and vanadium isotopes around the neutron number 40 at the RIKEN RI Beam Factory using the time-of-flight magnetic-rigidity technique. The atomic mass excesses of ^{58-60}Sc, ^{60-62}Ti, and ^{62-64}V were measured for the first time. The experimental results show that the two-neutron separation energies in the vicinity of ^{62}Ti increase compared to neighboring nuclei. This shows that the masses of Ti isotopes near N=40 are affected by the Jahn-Teller effect. Therefore, a development of Jahn-Teller stabilization appears below the Cr isotopes, and the systematics in Sc, Ti, and V isotopes suggest that ^{62}Ti is located close to the peak of the Jahn-Teller effect.

3.
Lupus ; 29(2): 176-181, 2020 Feb.
Article in English | MEDLINE | ID: mdl-31924143

ABSTRACT

OBJECTIVE: The objective of this study was to evaluate the chronic damage associated with pregnancies before and after the diagnosis of systemic lupus erythematosus (SLE). METHODS: Using childbearing-aged female SLE patient data registered at the Okayama and Showa University Hospitals, a nested case-control analysis was performed to investigate the relationship between pregnancy and chronic damage using the Systemic Lupus International Collaborating Clinics/American College of Rheumatology Damage Index (SDI). RESULTS: Pregnancy occurred in 22 patients before and 13 patients after the diagnosis of SLE in 104 eligible patients. Live births occurred in 82% (33/40) and 50% (9/18) of the pregnancies before and after the diagnosis of SLE, respectively. After matching age and disease duration, 33 case patients with chronic damage (SDI ≥ 1) and 33 control patients without chronic damage (SDI = 0) were selected. Hypertension was more frequent in cases than in controls (48% vs. 24%, p = 0.041). Pregnancies before and after the diagnosis of SLE were comparable between cases and controls (before the diagnosis: nine case patients and eight control patients; after the diagnosis: three case patients and five control patients; p = 1.00). Even after adjusting for hypertension using multivariate analysis, the pregnancies before and after the diagnosis were not significant predictors for chronic damage (odds ratio = 1.48 (95% confidence interval 0.33-6.65)), p = 0.60 of the pregnancy before the diagnosis; odds ratio = 0.78 (95% confidence interval 0.13-4.74), p = 0.78 of the pregnancy after the diagnosis). CONCLUSION: Pregnancies, either before or after the diagnosis of SLE, did not show any differences in chronic damage. Our results help alleviate fears regarding childbearing in female patients with SLE and their families.


Subject(s)
Health Status , Lupus Erythematosus, Systemic/physiopathology , Pregnancy Complications , Adult , Case-Control Studies , Cross-Sectional Studies , Female , Humans , Japan , Logistic Models , Lupus Erythematosus, Systemic/diagnosis , Multivariate Analysis , Pregnancy , Registries , Severity of Illness Index , Young Adult
4.
Phys Rev Lett ; 121(24): 242501, 2018 Dec 14.
Article in English | MEDLINE | ID: mdl-30608744

ABSTRACT

The isospin character of p-n pairs at large relative momentum has been observed for the first time in the ^{16}O ground state. A strong population of the J,T=1,0 state and a very weak population of the J,T=0,1 state were observed in the neutron pickup domain of ^{16}O(p,pd) at 392 MeV. This strong isospin dependence at large momentum transfer is not reproduced by the distorted-wave impulse approximation calculations with known spectroscopic amplitudes. The results indicate the presence of high-momentum protons and neutrons induced by the tensor interactions in the ground state of ^{16}O.

5.
Phys Rev Lett ; 120(17): 172501, 2018 Apr 27.
Article in English | MEDLINE | ID: mdl-29756826

ABSTRACT

The (^{12}N, ^{12}C) charge-exchange reaction at 175 MeV/u was developed as a novel probe for studying the isovector spin giant monopole resonance (IVSMR), whose properties are important for better understanding the bulk properties of nuclei and asymmetric nuclear matter. This probe, now available through the production of ^{12}N as a secondary rare-isotope beam, is exothermic, is strongly absorbed at the surface of the target nucleus, and provides selectivity for spin-transfer excitations. All three properties enhance the excitation of the IVSMR compared to other, primarily light-ion, probes, which have been used to study the IVSMR thus far. The ^{90}Zr(^{12}N,^{12}C) reaction was measured and the excitation energy spectra up to about 70 MeV for both the spin-transfer and non-spin-transfer channels were deduced separately by tagging the decay by γ emission from the ^{12}C ejectile. Besides the well-known Gamow-Teller and isobaric analog transitions, a clear signature of the IVSMR was identified. By comparing with the results from light-ion reactions on the same target nucleus and theoretical predictions, the suitability of this new probe for studying the IVSMR was confirmed.

6.
Phys Rev Lett ; 121(2): 022506, 2018 Jul 13.
Article in English | MEDLINE | ID: mdl-30085708

ABSTRACT

We perform the first direct mass measurements of neutron-rich calcium isotopes beyond neutron number 34 at the RIKEN Radioactive Isotope Beam Factory by using the time-of-flight magnetic-rigidity technique. The atomic mass excesses of ^{55-57}Ca are determined for the first time to be -18650(160), -13510(250), and -7370(990) keV, respectively. We examine the emergence of neutron magicity at N=34 based on the new atomic masses. The new masses provide experimental evidence for the appearance of a sizable energy gap between the neutron 2p_{1/2} and 1f_{5/2} orbitals in ^{54}Ca, comparable to the gap between the neutron 2p_{3/2} and 2p_{1/2} orbitals in ^{52}Ca. For the ^{56}Ca nucleus, an open-shell property in neutrons is suggested.

7.
Lupus ; 27(8): 1374-1377, 2018 Jul.
Article in English | MEDLINE | ID: mdl-29498304

ABSTRACT

We present a case of a woman with systemic lupus erythematosus (SLE) who had refractory episodes of neuromyelitis optica spectrum disorder (NMOSD) and was successfully treated with rituximab. She was positive for anti-aquaporin-4 (AQP4) antibody and had typical cranial and longitudinally extended spinal lesions but no optic nerve involvement. There is no established treatment for NMOSD/SLE overlap cases. Our experience suggests that rituximab may be effective for patients with combined SLE and anti-AQP4 antibody-positive NMOSD.


Subject(s)
Autoantibodies/blood , Lupus Erythematosus, Systemic/complications , Neuromyelitis Optica/drug therapy , Rituximab/therapeutic use , Aquaporin 4/immunology , Female , Humans , Magnetic Resonance Imaging , Neuromyelitis Optica/complications , Treatment Outcome , Young Adult
8.
Lupus ; 27(13): 2093-2100, 2018 Nov.
Article in English | MEDLINE | ID: mdl-30309286

ABSTRACT

OBJECTIVE: Serologically active clinically quiescent (SACQ)-SLE is a subtype of systemic lupus erythematosus (SLE); most SACQ-SLE patients relapse. Although complement and/or anti-dsDNA level fluctuations during SACQ status are reportedly not useful for predicting relapse, they might be useful in specific clinical settings. We aimed to assess the correlation between future relapse and progressive reductions in serum complement levels following remission in patients with hypocomplementemia . METHODS: We retrospectively reviewed patients aged ≥15 years who were treated with ≥20 mg/day of prednisolone for remission induction. After achieving remission, the patients treated with prednisolone tapered to ≤15 mg/day without relapse and followed by hypocomplementemia (first hypocomplementemia point) were analyzed. The primary outcome was the relapse during the first 24 months. RESULTS: Seventy-six patients were enrolled; 31 (40.8%) relapsed. A ≥10% reduction after the first hypocomplementemia point in serum C3, C4, and CH50 levels was found in 10, 21, and 16 patients, respectively. Hazard ratios (95% confidence intervals) for relapse were 2.32 (0.92-5.12) for serum C3 levels and 2.46 (1.18-5.01) for serum C4 levels. Progressive reductions in serum C3 and C4 levels had relatively high specificity (93.3% and 82.2%) but limited sensitivity (22.6% and 41.9%) for predicting relapse. However, simultaneous progressive reduction in C3 levels and increase in anti-dsDNA antibody levels had the highest specificity (97.8%), and simultaneous progressive reduction in C4 levels or increase in anti-dsDNA antibody levels had the highest sensitivity (71.0%). CONCLUSION: Simultaneous progressive reductions in complement levels and increases in anti-dsDNA antibody levels may indicate future relapse SACQ-SLE patients.


Subject(s)
Antibodies, Antinuclear/blood , Complement C3/analysis , Complement C4/analysis , Lupus Erythematosus, Systemic/blood , Adult , Female , Humans , Lupus Erythematosus, Systemic/immunology , Male , Middle Aged , Recurrence , Retrospective Studies , Risk Factors , Sensitivity and Specificity , Severity of Illness Index , Young Adult
9.
Opt Express ; 25(12): A491-A501, 2017 Jun 12.
Article in English | MEDLINE | ID: mdl-28788880

ABSTRACT

An Nd:YAG laser-based sodium temperature/wind lidar was developed for the measurement of the northern polar mesosphere and lower thermosphere at Tromsø (69.6N, 19.2E), Norway. Coherent light at 589 nm is produced by sum frequency generation of 1064 nm and 1319 nm from two diode laser end-pumped pulsed Nd:YAG lasers. The output power is as high as 4W, with 4 mJ/pulse at 1000 Hz repetition rate. Five tilting Cassegrain telescopes enable us to make five-direction (zenith, north, south, east, west) observation for temperature and wind simultaneously. This highly stable laser system is first of its kind to operate virtually maintenance-free during the observation season (from late September to March) since 2010.

10.
Phys Rev Lett ; 118(5): 052701, 2017 Feb 03.
Article in English | MEDLINE | ID: mdl-28211732

ABSTRACT

The cross sections of the ^{7}Be(n,α)^{4}He reaction for p-wave neutrons were experimentally determined at E_{c.m.}=0.20-0.81 MeV slightly above the big bang nucleosynthesis (BBN) energy window for the first time on the basis of the detailed balance principle by measuring the time-reverse reaction. The obtained cross sections are much larger than the cross sections for s-wave neutrons inferred from the recent measurement at the n_TOF facility in CERN, but significantly smaller than the theoretical estimation widely used in the BBN calculations. The present results suggest the ^{7}Be(n,α)^{4}He reaction rate is not large enough to solve the cosmological lithium problem, and this conclusion agrees with the recent result from the direct measurement of the s-wave cross sections using a low-energy neutron beam and the evaluated nuclear data library ENDF/B-VII.1.

11.
Phys Rev Lett ; 116(5): 052501, 2016 Feb 05.
Article in English | MEDLINE | ID: mdl-26894705

ABSTRACT

A candidate resonant tetraneutron state is found in the missing-mass spectrum obtained in the double-charge-exchange reaction ^{4}He(^{8}He,^{8}Be) at 186 MeV/u. The energy of the state is 0.83±0.65(stat)±1.25(syst) MeV above the threshold of four-neutron decay with a significance level of 4.9σ. Utilizing the large positive Q value of the (^{8}He,^{8}Be) reaction, an almost recoilless condition of the four-neutron system was achieved so as to obtain a weakly interacting four-neutron system efficiently.

12.
Lupus ; 25(1): 54-60, 2016 Jan.
Article in English | MEDLINE | ID: mdl-26296361

ABSTRACT

OBJECTIVE: We have assessed the effectiveness of tacrolimus for minor flares in systemic lupus erythematosus (SLE) patients. METHODS: The medical records of 313 patients were retrospectively reviewed over a period of seven years, from 2006 to 2013. We enrolled patients with minor flare treated with add-on tacrolimus, without glucocorticoid (GC) intensification (tacrolimus group). Minor flare was defined as a ≥ 1-point increase in a total score between 3 and 11 in the SLE Disease Activity Index (SLEDAI). We enrolled as controls patients who were administered increased doses of GC for minor flare (GC group). All patients were followed for one year. The primary outcome measure was the proportion of responders. RESULTS: There were 14 eligible patients in the tacrolimus group and 20 eligible patients in the GC group. The mean SLEDAI at flare tended to be higher in the tacrolimus group than in the GC group (7.5 vs. 6.2, p = 0.085). A mean dose of 1.6 mg tacrolimus/day was administered for flare, while the mean GC dose was 13.7 mg/day in the GC group. The proportion of responders was 86% (12/14) in the tacrolimus group and 75% (15/20) in the GC group (p = 0.67). The mean dose of GC at 12 months was higher in the GC group than in the tacrolimus group (9.7 mg/day vs. 7.1 mg/day, p < 0.05). Only one patient discontinued tacrolimus because of fatigue after three months. CONCLUSION: Adding tacrolimus without increasing the GC dose may provide an effective treatment option for minor flares in patients with SLE.


Subject(s)
Immunosuppressive Agents/administration & dosage , Lupus Erythematosus, Systemic/drug therapy , Tacrolimus/administration & dosage , Adult , Disease Progression , Drug Therapy, Combination , Female , Glucocorticoids/administration & dosage , Humans , Immunosuppressive Agents/adverse effects , Lupus Erythematosus, Systemic/diagnosis , Male , Medical Records , Middle Aged , Retrospective Studies , Severity of Illness Index , Tacrolimus/adverse effects , Time Factors , Treatment Outcome
13.
Phys Rev Lett ; 115(10): 102501, 2015 Sep 04.
Article in English | MEDLINE | ID: mdl-26382672

ABSTRACT

Differential cross sections of isoscalar and isovector spin-M1 (0(+)→1(+)) transitions are measured using high-energy-resolution proton inelastic scattering at E(p)=295 MeV on (24)Mg, (28)Si, (32)S, and (36)Ar at 0°-14°. The squared spin-M1 nuclear transition matrix elements are deduced from the measured differential cross sections by applying empirically determined unit cross sections based on the assumption of isospin symmetry. The ratios of the squared nuclear matrix elements accumulated up to E(x)=16 MeV compared to a shell-model prediction are 1.01(9) for isoscalar and 0.61(6) for isovector spin-M1 transitions, respectively. Thus, no quenching is observed for isoscalar spin-M1 transitions, while the matrix elements for isovector spin-M1 transitions are quenched by an amount comparable with the analogous Gamow-Teller transitions on those target nuclei.

14.
Euro Surveill ; 20(20)2015 May 21.
Article in English | MEDLINE | ID: mdl-26027484

ABSTRACT

We isolated eight highly pathogenic H5N8 avian influenza viruses (H5N8 HPAIVs) in the 2014/15 winter season at an overwintering site of migratory birds in Japan. Genetic analyses revealed that these isolates were divided into three groups, indicating the co-circulation of three genetic groups of H5N8 HPAIV among these migratory birds. These results also imply the possibility of global redistribution of the H5N8 HPAIVs via the migration of these birds next winter.


Subject(s)
Animal Migration , Birds/virology , Genetic Variation , Influenza A virus/genetics , Influenza A virus/isolation & purification , Animals , Influenza A virus/classification , Influenza A virus/pathogenicity , Influenza in Birds/virology , Japan , Phylogeny , Seasons , Sequence Analysis, DNA
15.
Clin Exp Allergy ; 43(9): 1027-37, 2013 Sep.
Article in English | MEDLINE | ID: mdl-23957338

ABSTRACT

BACKGROUND: Patients with Stevens-Johnson syndrome (SJS) or toxic epidermal necrolysis (TEN) are often exposed simultaneously to a few potentially culprit drugs. However, both the standard lymphocyte transformation tests (LTT) with proliferation as the assay end-point as well as skin tests, if done, are often negative. OBJECTIVE: As provocation tests are considered too dangerous, there is an urgent need to identify the relevant drug in SJS/TEN and to improve sensitivity of tests able to identify the causative drug. METHODS: Fifteen patients with SJS/TEN with the ALDEN score ≥ 6 and 18 drug-exposed controls were included. Peripheral blood mononuclear cells (PBMC) were isolated and cultured under defined conditions with drugs. LTT was compared to the following end-points: cytokine levels in cell culture supernatant, number of granzyme B secreting cells by ELISpot and intracellular staining for granulysin and IFNγ in CD3(+) CD4(+), CD3(+) CD8(+) and NKp46(+) cells. To further enhance sensitivity, the effect of IL-7/IL-15 pre-incubation of PBMC was evaluated. RESULTS: Lymphocyte transformation tests was positive in only 4/15 patients (sensitivity 27%, CI: 8-55%). Similarly, with granzyme B-ELISpot culprit drugs were positive in 5/15 patients (sensitivity 33%, CI: 12-62%). The expression of granulysin was significantly induced in NKp46(+) and CD3(+) CD4(+) cells (sensitivity 40%, CI: 16-68% and 53%, CI: 27-79% respectively). Cytokine production could be demonstrated in 38%, CI: 14-68% and 43%, CI: 18-71% of patients for IL-2 and IL-5, respectively, and in 55%, CI: 23-83% for IFNγ. Pre-incubation with IL-7/IL-15 enhanced drug-specific response only in a few patients. Specificities of tested assays were in the range of 95 (CI: 80-99%)-100% (CI: 90-100%). CONCLUSIONS AND CLINICAL RELEVANCE: Granulysin expression in CD3(+) CD4(+) , Granzyme B-ELISpot and IFNγ production considered together provided a sensitivity of 80% (CI: 52-96%) and specificity of 95% (80-99%). Thus, this study demonstrated that combining different assays may be a feasible approach to identify the causative drug of SJS/TEN reactions; however, confirmation on another group of patients is necessary.


Subject(s)
Lymphocyte Activation/immunology , Lymphocytes/immunology , Stevens-Johnson Syndrome/etiology , Adult , Aged , Antigens, Differentiation, T-Lymphocyte/biosynthesis , Cytokines/metabolism , Cytokines/pharmacology , Drug-Related Side Effects and Adverse Reactions/immunology , Female , Granzymes/metabolism , Humans , Interleukin-15/pharmacology , Interleukin-7/pharmacology , Leukocytes, Mononuclear/drug effects , Leukocytes, Mononuclear/immunology , Leukocytes, Mononuclear/metabolism , Lymphocyte Activation/drug effects , Lymphocytes/drug effects , Lymphocytes/metabolism , Male , Middle Aged , ROC Curve , Stevens-Johnson Syndrome/diagnosis , Stevens-Johnson Syndrome/immunology , Young Adult
16.
Br J Dermatol ; 169(5): 992-9, 2013 Nov.
Article in English | MEDLINE | ID: mdl-23855761

ABSTRACT

BACKGROUND: The Janus kinase (JAK) inhibitor, tofacitinib, has shown efficacy for the treatment of psoriasis in a phase IIb trial (A3921047; NCT00678210). OBJECTIVES: To report haematology data from the phase IIb trial, given the importance of JAK-dependent signalling in haematopoiesis. METHODS: Patients with moderate-to-severe chronic plaque psoriasis were randomized to receive tofacitinib 2, 5 or 15 mg, or placebo, twice daily over 12 weeks. Blood samples were collected at screening, baseline, weeks 2, 4, 8 and 12 during treatment, and weeks 14 and 16 during off-treatment follow-up. RESULTS: Baseline haematology was similar across patients receiving tofacitinib 2 mg (n = 49), 5 mg (n = 49) or 15 mg (n = 49), or placebo (n = 50). Tofacitinib conferred dose-dependent decreases in haemoglobin, haematocrit and red blood cell counts, while reticulocyte counts initially declined, before recovering by week 8, and exceeding baseline levels after treatment cessation. With regard to white blood cells, tofacitinib had no clear dose-dependent effects on basophils or monocytes, but appeared to be associated with transient or reversible dose-dependent decreases in neutrophil and eosinophil counts and transient increases in lymphocyte counts, which were primarily attributable to increases in B-cell counts. Natural killer cell counts declined with tofacitinib. CONCLUSIONS: Tofacitinib conferred tolerable, dose-dependent changes in haematological parameters during short-term administration in patients with psoriasis. The effects did not appear to be progressive, and were often transient or reversible.


Subject(s)
Dermatologic Agents/administration & dosage , Piperidines/administration & dosage , Protein Kinase Inhibitors/therapeutic use , Psoriasis/drug therapy , Pyrimidines/administration & dosage , Pyrroles/administration & dosage , Adolescent , Adult , Aged , Basophils/drug effects , Blood Cell Count , Chronic Disease , Dose-Response Relationship, Drug , Female , Hematocrit , Hemoglobins/drug effects , Humans , Killer Cells, Natural/drug effects , Leukocytes/drug effects , Male , Middle Aged , Monocytes/drug effects , Young Adult
17.
Phys Rev Lett ; 108(26): 262501, 2012 Jun 29.
Article in English | MEDLINE | ID: mdl-23004969

ABSTRACT

A high-resolution measurement of inelastic proton scattering off (90)Zr near 0° was performed at 295 MeV with a focus on a pronounced strength previously reported in the low-energy tail of giant dipole resonance. A forest of fine structure was observed in the excitation energy region 7-12 MeV. A multipole decomposition analysis of the angular distribution for the forest was carried out using the ECIS95 distorted-wave Born approximation code with the Hartree-Fock plus random-phase approximation model of E1 and M1 transition densities and inclusion of E1 Coulomb excitation. The analysis separated pygmy dipole and M1 resonances in the forest at E(PDR)=9.15±0.18 MeV with Γ(PDR)=2.91±0.64 MeV and at E(M1)=9.53±0.06 MeV with Γ(M1)=2.70±0.17 MeV in the Lorentzian function, respectively. The B(E1)↑ value for pygmy dipole resonance over 7-11 MeV is 0.75±0.08 e(2)fm(2), which corresponds to 2.1±0.2% of the Thomas-Reiche-Kuhn sum rule.

18.
Phys Rev Lett ; 108(26): 262503, 2012 Jun 29.
Article in English | MEDLINE | ID: mdl-23004971

ABSTRACT

The double-differential cross sections for the (208)Pb and (90)Zr(t,(3)He) reactions at 300 MeV/u have been measured at the RI Beam Factory at RIKEN. This was the first physics experiment with the SHARAQ magnetic spectrometer. The combined analysis of the present (t,(3)He) data and previous (n,p) data provides the clearest identification for the ß(+) isovector spin monopole resonance both in the (208)Tl and (90)Y nuclei, and puts the observations of this giant resonance on a firm foundation. The measured distributions of the (t,(3)He) monopole cross sections were well reproduced by the distorted-wave Born approximation calculation, where the target transition density was calculated with the self-consistent Hartree-Fock plus random-phase approximation using the T43 Skyrme interaction. A major part of the expected ß(+) isovector spin monopole strength was found in the measured cross section spectra.

19.
Phys Rev Lett ; 108(22): 222501, 2012 Jun 01.
Article in English | MEDLINE | ID: mdl-23003590

ABSTRACT

The reduced transition probability B(E2;0(gs)(+)→2(1)(+)) for (28)S was obtained experimentally using Coulomb excitation at 53 MeV/nucleon. The resultant B(E2) value 181(31) e(2)fm(4) is smaller than the expectation based on empirical B(E2) systematics. The double ratio |M(n)/M(p)|/(N/Z) of the 0(gs)(+)→2(1)(+) transition in (28)S was determined to be 1.9(2) by evaluating the M(n) value from the known B(E2) value of the mirror nucleus (28)Mg, showing the hindrance of proton collectivity relative to that of neutrons. These results indicate the emergence of the magic number Z=16 in the |T(z)|=2 nucleus (28)S.

20.
Allergy ; 67(1): 58-66, 2012 Jan.
Article in English | MEDLINE | ID: mdl-21933197

ABSTRACT

BACKGROUND: Up to 10% of patients with severe immune-mediated drug hypersensitivity reactions have tendencies to develop multiple drug hypersensitivities (MDH). The reason why certain individuals develop MDH and the underlying pathomechanism are unclear. We investigated different T cell subpopulations in MDH patients and compared them with patients allergic to a single drug and with healthy controls (HC). METHODS: We analyzed the in vitro reactivity of peripheral blood mononuclear cells from MDH patients (n=7), patients with hypersensitivity to a single drug (monoallergic, n=6), and healthy controls (HD) (n=6) to various drugs (mainly antibiotics and antiepileptics). By depleting and selectively re-adding CD4(+) CD25(bright) T cells (T regulatory cells, Treg), their effect on drug-specific T cell reactivity was analyzed. The phenotype of reacting T cells was determined ex vivo by staining for markers of activation (CD38) and cell exhaustion (PD-1). RESULTS: No functional deficiency of Treg cells was observed in all drug-allergic patients. Drug-reactive T cells from MDH patients were found in the CD4(+) CD25(dim) T cell fraction and showed enhanced CD38 and PD-1 expression, while those from monoallergic patients reside in the resting CD4(+) CD25(neg) T cell fraction. CONCLUSION: In patients with MDH, the drug-reactive T cells are contained in an in vivo pre-activated T cell fraction. Therefore, they may show a lower threshold for activation by drugs. The reason for this in vivo T cell pre-activation needs further investigations.


Subject(s)
Drug Hypersensitivity/immunology , Lymphocyte Activation/immunology , T-Lymphocyte Subsets/immunology , T-Lymphocytes, Regulatory/immunology , Cell Separation , Cells, Cultured , Flow Cytometry , Humans , Immunomagnetic Separation , Immunophenotyping
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