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1.
Opt Express ; 32(3): 4102-4110, 2024 Jan 29.
Artículo en Inglés | MEDLINE | ID: mdl-38297618

RESUMEN

In this manuscript, what we believe to be a novel hyperbolic-graded topological nano-photonic resonator structure is proposed to excite robust topological edge states. The graded refractive index is realized by considering a porous silicon material having a deliberately modulated local refractive index. The introduction of grading effectively modifies its dispersion characteristics leading to distinctive topological properties. This results in excitation of a topologically protected edge state (TES) having significantly higher interface electric field intensity at an operational wavelength of 1521 nm. Additionally, the impact of interface layer thicknesses on the excitation of these TES is thoroughly investigated. Finally, the structure's capability to be used as a refractive index sensor is also demonstrated. The analytical results demonstrate an average sensitivity of 852.14 nm/RIU, coupled with a quality factor of 4019.23 and a figure of merit (FOM) of 1277.13 RIU-1. With its remarkable performance metrics, the proposed device holds significant promise for accurately detecting and sensing biochemical samples with very high efficiency.

2.
Clin Endocrinol (Oxf) ; 100(3): 203-211, 2024 03.
Artículo en Inglés | MEDLINE | ID: mdl-37997487

RESUMEN

OBJECTIVE: Overnight metyrapone test (OMT) is a dynamic test used to diagnose secondary adrenal insufficiency (SAI). Data on OMT use and its safety are scarce. We aimed to describe the indications and safety of outpatient OMT and compare OMT to the cosyntropin stimulation test (CST). DESIGN: Single-centre retrospective study of adult patients undergoing OMT between 1 April 2018 and 27 January 2023. MEASUREMENTS: OMT-related adverse events, post-OMT diagnosis of SAI, and OMT comparison to CST. RESULTS: OMT was performed in 114 patients (81, 71% women) at a median age of 48 (interquartile range 37-58). The pretest probability for SAI was low in 52 (46%) patients, moderate in 48 (42%) patients and high in 14 (12%) patients. Adverse events were reported in 7 (6.1%) patients and were mild except for one hospitalization. No baseline or OMT-related factors were associated with the development of adverse events. Prevalence of the OMT-based SAI diagnosis was 26 (23%) and 47 (46%) using 11-deoxycortisol cutoff <7 and <10 mcg/dL, respectively. Higher pretest probability was associated with the OMT-based diagnosis of SAI. Post-OMT 11-deoxycortisol cutoff of 10 mcg/dL was used most to diagnose SAI. Compared to the OMT-based diagnosis of SAI (11-deoxycortisol cutoff of 10 mcg/dL), the specificity of CST was 100%, but the sensitivity was only 52%. CONCLUSIONS: OMT was well tolerated and used in patients with low and moderate pretest probability for SAI. CST can erroneously exclude patients with SAI. Thus, OMT should be considered in selected patients with normal CST.


Asunto(s)
Insuficiencia Suprarrenal , Metirapona , Adulto , Humanos , Femenino , Masculino , Estudios Retrospectivos , Cortodoxona , Insuficiencia Suprarrenal/diagnóstico , Cosintropina , Hidrocortisona
3.
JCEM Case Rep ; 2(1): luad143, 2024 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-38192879

RESUMEN

Estrogen-secreting adrenocortical carcinoma (ACC) is exceedingly rare, representing 1% to 2% of all ACCs. We present a case of a 65-year-old man diagnosed with an estrogen-secreting, 4.3-cm right adrenal mass discovered during work-up for bilateral gynecomastia. Gynecomastia and hyperestrogenism resolved after laparoscopic adrenalectomy, and pathology was reported as adrenocortical adenoma. However, 5 years later, he again developed bilateral gynecomastia because of recurrent hyperestrogenism. Imaging revealed multiple metastases in the abdomen. Urine steroid profiling demonstrated increased androgen precursors, androgen metabolites, and glucocorticoid precursors. Ultrasound-guided biopsy of one of the metastases confirmed ACC. Initial therapy included debulking surgery with removal of metastatic lesions. Mitotane therapy was initiated 4 weeks later along with hydrocortisone for anticipated mitotane-induced adrenal insufficiency. Histopathology from the adrenalectomy specimen 5 years earlier was rereviewed and confirmed ACC. Estrogen-secreting adrenal tumors are exceedingly rare, and the majority are malignant. This case underlines the importance of making an initial accurate diagnosis of adrenal malignancy that allows better surgical planning and appropriate monitoring. Indeterminate imaging characteristics of the adrenal mass, as well as the presentation with estrogen excess, suggested an elevated risk for ACC. Initial pathology-based misdiagnosis illustrates the need for an expert adrenal pathologist to review these rare tumors.

4.
Artículo en Inglés | MEDLINE | ID: mdl-38870260

RESUMEN

CONTEXT: Patients with nonfunctioning adenomas (NFA), adenomas with mild autonomous cortisol secretion (MACS) and Cushing syndrome (CS) demonstrate an increased cardiovascular risk. OBJECTIVE: To determine the extent of lipoprotein abnormalities in NFA, MACS, and CS. METHODS: We conducted a single-center cross-sectional study of patients with NFA (n = 167), MACS (n = 213), CS (n = 142) and referent subjects (n = 202) between January 2015 and July 2022. Triglyceride-rich lipoprotein particles (TRLP), low density lipoprotein particles (LDLP), high density lipoprotein particles (HDLP), their subclasses and sizes were measured using nuclear magnetic resonance spectroscopy. Multivariable logistic analyses were adjusted for age, sex, BMI, smoking, hypertension, diabetes and lipid lowering drug therapy. RESULTS: In age- and sex-adjusted analysis, all patients categories demonstrated increased very large TRLP, large TRLP and greater TRL size (odds ratio (OR) ranging from 1.22 to 2.08) and total LDLP (OR ranging from 1.22 to 1.75) and decreased LDL and HDL size compared to referent subjects. In fully adjusted analysis, LDLP concentrations remained elevated in all patient categories (odds ratios ranging from 1.31 to 1.84). Total cholesterol, LDL cholesterol, triglycerides and apolipoprotein B were also higher in all patient categories in age- and sex-adjusted analysis with apoB remaining elevated in all patient categories in fully adjusted analysis. Similar LDLP and apoB elevations were observed in all patient categories after excluding subjects on lipid lowering therapy. CONCLUSION: Patients with overt, mild, and even absent cortisol excess demonstrate lipoprotein profile abnormalities, in particular, high LDLP and apoB concentrations, which conceivably contribute to high cardiometabolic risk.

5.
Artículo en Inglés | MEDLINE | ID: mdl-38546526

RESUMEN

CONTEXT: Patients with adrenal hormone excess demonstrate increased cardiovascular risk and mortality. OBJECTIVE: We aimed to determine the impact of adrenal disorders on the inflammation marker GlycA, total branched-chain amino acids (BCAA), ketone bodies and the gut microbiome-derived metabolites trimethylamine N-oxide (TMAO) and betaine. METHODS: We conducted a single-center cross-sectional study of patients with nonfunctioning adenomas (NFA), mild autonomous cortisol secretion (MACS), primary aldosteronism (PA), Cushing syndrome (CS), pheochromocytoma/paragangliomas (PPGL), other benign or malignant adrenal masses, and adrenocortical carcinoma (ACC) between January 2015 and July 2022 (n=802). Referent subjects included participants of the PREVEND (Prevention of Renal and Vascular End-stage Disease) study (n=5241). GlycA, BCAA, ketone bodies, TMAO, and betaine were measured using nuclear magnetic resonance spectroscopy. Multivariable logistic analyses were adjusted for age, sex, BMI, smoking, hypertension, diabetes mellitus and statin therapy. RESULTS: In age-and sex-adjusted comparison to referent subjects, increased GlycA was noted in all patient categories, increased BCAA in NFA, MACS, CS, PA and ACC, increased TMAO in patients with other malignant adrenal masses, increased betaine in NFA and MACS, and increased ketone bodies in NFA, CS and ACC. Essentially similar findings were observed in fully adjusted analysis and after exclusion of subjects with diabetes and cardiovascular disease. CONCLUSION: Patients with functioning and non-functioning adrenal masses demonstrated increased GlycA and BCAA, biomarkers associated with adverse cardiometabolic disorders and mortality. Patients with NFA demonstrated an adverse metabolic profile similar to patients with MACS and CS.

6.
Sci Rep ; 13(1): 1431, 2023 Jan 25.
Artículo en Inglés | MEDLINE | ID: mdl-36697424

RESUMEN

In this manuscript, a novel photonic crystal resonator (PhCR) structure having an exponentially graded refractive index profile is proposed to regulate and alter the dispersion characteristics for the first time. The structure comprises silicon material, where porosity is deliberately introduced to modulate the refractive index profile locally. The structural parameters are optimized to have a resonant wavelength of 1550 nm. Further, the impact of various parameters like incidence angle, defect layer thickness, and analyte infiltration on device performance is evaluated. Finally, the sensing capability of the proposed structure is compared with the conventional step index-based devices. The proposed structure exhibits an average sensitivity of 54.16 nm/RIU and 500.12 nm/RIU for step index and exponentially graded index structures. This exhibits the generation of a lower energy resonating mode having 825% higher sensitivity than conventional resonator structures. Moreover, the graded index structures show a 45% higher field confinement than the conventional PhCR structure.

7.
Clin Transl Gastroenterol ; 14(8): e00621, 2023 08 01.
Artículo en Inglés | MEDLINE | ID: mdl-37440319

RESUMEN

INTRODUCTION: Drug induced acute pancreatitis is a difficult diagnosis for clinicians. We previously published an "Evidence-Based Classification System" on Drug-Induced Acute Pancreatitis widely used by clinicians to assist in the identification of drugs. Unfortunately, this prior analysis based only on published case reports has been misunderstood. The prior review did not include studies with higher evidentiary value, such as randomized trials, case-control studies, and/or pharmacoepidemiologic studies. The use of the prior classification system has led to many patients being inappropriately labeled as having drug-induced acute pancreatitis. We now propose a "Revised" Evidence- Based Classification System for the purpose of determining which drugs cause acute pancreatitis based on the Grading of Recommendations, Development, and Evaluation criteria. METHODS: A search of the English Language literature was performed to identify all case reports with medication and/or drug induced acute pancreatitis. We divided the drugs implicated as causing acute pancreatitis into four groups based on the quality of evidence as defined by GRADE quality parameters. RESULTS: Although 141 drugs were identified in the literature as causing acute pancreatitis, only 106 drugs published in the literature as causing acute pancreatitis were high quality case reports. Only 3 drugs had evidence as causing acute pancreatitis from randomized controlled clinical trials, including 6-mercaptopurine and azathioprine. DISCUSSION: The vast majority of drugs implicated as causing acute pancreatitis in the literature have low or very low quality of evidence supporting those claims.


Asunto(s)
Pancreatitis , Humanos , Pancreatitis/inducido químicamente , Pancreatitis/diagnóstico , Enfermedad Aguda , Estudios de Casos y Controles
8.
Artículo en Inglés | MEDLINE | ID: mdl-38157409

RESUMEN

OBJECTIVE: Patients with nonfunctioning adrenal adenomas (NFA) and mild autonomous cortisol secretion (MACS) demonstrate an increased risk of chronic kidney disease (CKD), however factors associated with CKD are unknown. We aimed to identify the factors associated with CKD and assess the impact of adrenalectomy on kidney function in patients with NFA or MACS. DESIGN: Single-center cohort study of patients with NFA and MACS, 1999-2020. METHODS: MACS was diagnosed based on post-dexamethasone cortisol (DST) ≥ 1.8 mcg/dL. Age, sex, dysglycemia, hypertension, therapy with statin, angiotensin converting enzyme inhibitor, or angiotensin II receptor blocker were included in the multivariable analysis. Outcomes included estimated glomerular filtration rate (eGFR) at the time of diagnosis with MACS or NFA and post-adrenalectomy delta eGFR. RESULTS: Of 972 patients, 429 (44%) had MACS and 543 (56%) had NFA. At the time of diagnosis, patients with MACS had lower eGFR (median 79.6 vs 83.8 ml/min/1.73m2, p < 0.001) than patients with NFA. In a multivariable analysis, factors associated with lower eGFR were older age, hypertension, and higher DST. In 204 patients (MACS: 155, 76% and NFA: 49, 24%) treated with adrenalectomy, post adrenalectomy eGFR improved in both groups starting at 18 months up to 3.5 years of follow up. Factors associated with increased eGFR were younger age, lower pre-adrenalectomy eGFR and longer follow-up period. CONCLUSION: DST cortisol is an independent risk factor for lower eGFR in patients with adrenal adenomas. Both patients with MACS and NFA demonstrate an increase in eGFR post-adrenalectomy, especially younger patients with lower eGFR pre-adrenalectomy.

9.
Eur J Endocrinol ; 188(7): 603-612, 2023 Jul 10.
Artículo en Inglés | MEDLINE | ID: mdl-37327378

RESUMEN

OBJECTIVE: Prospective data on determinants of muscle strength impairment and quality of life in patients with various subtypes and severity of endogenous hypercortisolism are lacking. DESIGN: Single-center cross-sectional study, 2019 to 2022. METHODS: Patients with Cushing syndrome (CS) and mild autonomous cortisol secretion (MACS) were assessed with clinical and biochemical severity scores, muscle function (nondominant hand grip strength and sit-to-stand test), and quality of life (Short Form-36 [SF36] and CushingQoL). Referent subjects were recruited from the local population undergoing abdominal imaging for reasons other than suspected adrenal disorder. RESULTS: Of 164 patients, 81 (49%) had MACS, 14 (9%) had adrenal CS, 60 (37%) had pituitary CS, and 9 (5%) had ectopic CS. Median age was 53 years (interquartile range: 42-63 years), and 126 (77%) were women. The SF36 mental component score was similarly low in patients with MACS vs CS, but physical component score was lower in CS when compared to MACS (mean of 34.0 vs 40.5, P = .001). Compared to MACS, patients with CS had lower scores on the standardized CushingQoL (mean of 47.1 vs 34.2, P < .001). Compared to referent subjects, patients with MACS demonstrated reduced muscle strength, similar to patients with CS (mean sit to stand Z-score of -0.47 vs -0.54, P = .822). Clinical severity (r = -0.22, P = .004) but not biochemical severity was associated with sit-to-stand test performance. CONCLUSIONS: Both patients with overt CS and MACS demonstrate reduced muscle strength and low quality of life. The clinical severity score utilized is associated with both physical and psychosocial components of CushingQoL and with the physical component of SF36.


Asunto(s)
Síndrome de Cushing , Enfermedades Musculares , Humanos , Femenino , Persona de Mediana Edad , Masculino , Síndrome de Cushing/complicaciones , Estudios Transversales , Calidad de Vida , Estudios Prospectivos , Fuerza de la Mano , Músculos , Hidrocortisona
10.
Eur J Endocrinol ; 189(3): 318-326, 2023 Sep 01.
Artículo en Inglés | MEDLINE | ID: mdl-37590964

RESUMEN

OBJECTIVE: Frailty, characterized by multi-system decline, increases vulnerability to adverse health outcomes and can be measured using Frailty Index (FI). We aimed to assess the prevalence of frailty in patients with adrenal disorders (based on hormonal sub-type) and examine association between FI and performance-based measures of physical function. DESIGN: Multi-centre, cross-sectional study (March 2019-August 2022). METHODS: Adult patients with adrenal disorders (non-functioning adrenal adenomas [NFA], mild autonomous cortisol secretion [MACS], Cushing syndrome [CS], primary aldosteronism [PA]) and referent subjects without adrenal disorders completed a questionnaire encompassing 47 health variables (comorbidities, symptoms, daily living activities). FI was calculated as the average score of all variables and frailty defined as FI ≥ 0.25. Physical function was assessed with hand grip, timed up-and-go test, chair rising test, 6-minute walk test, and gait speed. RESULTS: Compared to referent subjects (n = 89), patients with adrenal disorders (n = 520) showed increased age, sex, and body mass index-adjusted prevalence of frailty (CS [odds ratio-OR 19.2, 95% confidence interval-CI 6.7-70], MACS [OR 12.5, 95% CI 4.8-42.9], PA [OR 8.4, 95% CI 2.9-30.4], NFA [OR 4.5, 95% CI 1.7-15.9]). Prevalence of frailty was similar to referent subjects when post-dexamethasone cortisol was <28 nmol/L and was higher when post-dexamethasone cortisol was 28-50 nmol/L (OR 4.6, 95% CI 1.7-16.5). FI correlated with all measures of physical function (P < .001). CONCLUSIONS: Whilst frailty prevalence was highest in patients with adrenocortical hormone excess, even patients with NFA demonstrated an increased prevalence compared to the referent population. Future longitudinal studies are needed to evaluate the impact of various management strategies on frailty.


Asunto(s)
Adenoma , Adenoma Corticosuprarrenal , Síndrome de Cushing , Fragilidad , Adulto , Humanos , Estudios Transversales , Prevalencia , Fragilidad/epidemiología , Fuerza de la Mano , Hidrocortisona , Estudios Prospectivos , Dexametasona , Adenoma/epidemiología
11.
Radiol Case Rep ; 17(9): 3147-3150, 2022 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-35801123

RESUMEN

Septo-optic dysplasia (SOD) is a rare congenital disorder occurring in only 1 in 10,000 live births. Initially it was described in 1941 by Reeves and further discussed by the French-Swiss neurologist de Morsier (1956) as the disease further addressed his name. SOD is a combination of triads of hypoplasia of the optic nerve, agenesis of midline brain structures, and hypoplasia of the hypothalamic-pituitary axis. The pathophysiology of this rare congenital anomaly is yet to be understood, with some hypotheses in order to establish the diagnosis. The management modality depends on the presentation of the disease and requires a multidisciplinary approach. While most SOD patients present with visual, neurological, or endocrine abnormalities, in our case the patient was diagnosed incidentally while following up after an episode of acute respiratory distress syndrome and sepsis. We aim to highlight the aspects of clinical presentation in a patient with SOD and the importance of a multimodality follow-up approach.

12.
Rheumatol Ther ; 9(2): 391-409, 2022 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-34878629

RESUMEN

INTRODUCTION: The biologics abatacept and adalimumab have different mechanisms of action (MoAs). We analyzed data from patients with rheumatoid arthritis treated in AMPLE (NCT00929864) to explore the pharmacodynamic effects of abatacept or adalimumab on anti-citrullinated protein antibodies (ACPAs) and gene expression. METHODS: AMPLE was a phase IIIb, 2-year, randomized, head-to-head trial of abatacept versus adalimumab. Post hoc analyses of baseline anti-cyclic citrullinated peptide-2 (anti-CCP2, an ACPA surrogate) positive (+) status and ACPA fine-specificity profiles over time, as well as transcriptional profiling (peripheral whole blood), were performed. RESULTS: Of 646 patients treated (abatacept, n = 318; adalimumab, n = 328), ACPA and gene expression data were available from 508 and 566 patients, respectively. In anti-CCP2+ patients (n = 388), baseline fine specificities for most ACPAs were highly correlated; over 2 years, levels decreased with abatacept but not adalimumab. By year 2, expression of genes associated with T cell co-stimulation and antibody production was lower for abatacept versus adalimumab; expression of genes associated with proinflammatory signaling was lower for adalimumab versus abatacept. Treatment modulated the expression of T- and B-cell gene signatures, with differences in CD8+ T cells, activated T cells, plasma cells, B cells, natural killer cells (all lower with abatacept versus adalimumab), and polymorphonuclear leukocytes (higher with abatacept versus adalimumab). CONCLUSIONS: In AMPLE, despite similar clinical outcomes, data showed that pharmacodynamic/genetic changes after 2 years of abatacept or adalimumab were consistent with drug MoAs. Further assessment of the relationship between such changes and clinical outcomes, including prediction of response, is warranted. TRIAL REGISTRATION: ClinicalTrials.gov identifier, NCT00929864.

13.
Radiol Case Rep ; 17(10): 3974-3978, 2022 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-35991384

RESUMEN

Biliary cystadenoma is a very uncommon benign cystic neoplasm involving the liver and the biliary tract. Most common presentations include right upper quadrant pain, nausea, vomiting, obstructive jaundice, and enlarging liver size. It can mimic many more commonly occurring diseases such as hepatic cyst, hepatic abscess, hydatid disease of the liver, and hepatic tuberculosis. Hence it becomes very challenging for physicians to correctly diagnose it due to its rarity and similarity with other conditions. Furthermore, very few pieces of literature guide physicians in correctly identifying the disease. Based on his physical examination and detailed investigation, we present a case report of a 72-year-old female diagnosed with biliary cystadenoma. We hope that this case report will significantly add to the existing literature on this subject.

14.
Radiol Case Rep ; 17(11): 4152-4155, 2022 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-36105843

RESUMEN

Superficial siderosis of the central nervous system is a chronic condition characterized by hemosiderin deposition in the brain and spinal cord. It's diagnosed by brain MRI. It can be caused by low-grade extravasation of blood into the subarachnoid space of the brain. There are 2 types of superficial siderosis cortical and infratentorial. Although asymptomatic in many cases; Cerebellar-predominant siderosis, a subtype of infratentorial, can affect hearing, gait, and even muscles. In this report, we present a case of a 51-year old female with complaints of hearing loss, unsteadiness in his lower limb, and spastic paresis. During MRI neuroimaging, we noticed findings of hypointensity areas within the brainstem and cerebellum, probably due to hemosiderin deposition. Based on the MRI findings, the patient was diagnosed with superficial siderosis. The patient was started on deferiprone and followed for the consecutive 18 months. Moderate improvement of the hearing loss and ataxia was noted while no change in muscle force. However, the repetitive MRI did not reveal any changes compared to the previous one.

15.
Cancer Invest ; 29(9): 599-607, 2011 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-22011282

RESUMEN

A guanine insertion polymorphism in matrix metalloproteinase-1 promoter (MMP-1 2G) is linked to early onset and aggressiveness in cancer. We determined the role of MMP-1 2G on MMP-1 expression and breast cancer severity in patients with breast diseases. We observed no significant difference in genotype distribution among different disease groups. However, MMP-1 expression was significantly higher in atypical ductal hyperplasia than in benign breast disease and in invasive breast cancer compared to in situ breast cancer. MMP-1 2G insertion polymorphism in the invasive group also correlated significantly with the expression of MMP-1 and breast cancer prognostic markers HER2 and P53.


Asunto(s)
Neoplasias de la Mama/enzimología , Neoplasias de la Mama/genética , Metaloproteinasa 1 de la Matriz/biosíntesis , Metaloproteinasa 1 de la Matriz/genética , Anciano , Femenino , Genotipo , Humanos , Inmunohistoquímica , Persona de Mediana Edad , Polimorfismo de Nucleótido Simple , Receptor ErbB-2/biosíntesis , Proteína p53 Supresora de Tumor/biosíntesis
16.
HCA Healthc J Med ; 1(5): 315-316, 2020.
Artículo en Inglés | MEDLINE | ID: mdl-37426609

RESUMEN

Description This painting was inspired by one patient's mindfulness practice that he developed to cope with depression of a recent loved one's death. Similar to my family of green thumbs, this patient found catharsis in cultivating his late wife's garden of fruits and vegetables after her death. Through mental health practices such as meditation and exercise, a person has a chance to process and heal from difficult circumstances.

17.
Cureus ; 12(7): e9419, 2020 Jul 27.
Artículo en Inglés | MEDLINE | ID: mdl-32754418

RESUMEN

There are few literatures highlighting the presence of a mycotic aneurysm in the setting of bloodstream infection by Serratia. A 33-year-old male with a history of Marfan syndrome, mitral valve prolapse, and intravenous drug use (IVDU) presented to the ED with fever, nausea, and non-bloody emesis, and vague abdominal pain with concern for sepsis. With the strong association between IVDU and infective endocarditis, transthoracic and transesophageal echocardiograms were performed and were negative for vegetations. Abdominal CT and positron emission tomography (PET) scan were performed and revealed thrombosis at the first jejunal branch of the superior mesenteric artery (SMA), left renal pole infarct, and superior splenic pole infarct. Following CT angiography for potential thrombolysis, aneurysmal formation was discovered proximal to the filling defect within mid-SMA. Blood cultures drawn at presentation grew Serratia marcescens. The patient was treated with appropriate antibiotic, and recommended indefinite anticoagulation. The patient was then recommended to follow up with vascular surgery within two weeks for repeat abdominal CT angiogram.

18.
Mol Immunol ; 65(1): 157-67, 2015 May.
Artículo en Inglés | MEDLINE | ID: mdl-25660968

RESUMEN

The exceptional ability of B cells to diversify through somatic mutation and improve affinity of the repertoire toward the antigens is the cornerstone of adaptive immunity. Somatic mutation is not evenly distributed and exhibits certain micro-sequence specificities. We show here that the combination of somatic mutation targeting and the codon usage in human B cell receptor (BCR) Variable (V) genes create expected patterns of mutation and post mutation changes that are focused on their complementarity determining regions (CDR). T cell V genes are also skewed in targeting mutations but to a lesser extent and are lacking the codon usage bias observed in BCRs. This suggests that the observed skew in T cell receptors is due to their amino acid usage, which is similar to that of BCRs. The mutation targeting and the codon bias allow B cell CDRs to diversify by specifically accumulating nonconservative changes. We counted the distribution of mutations to CDR in 4 different human datasets. In all four cases we found that the number of actual mutations in the CDR correlated significantly with the V gene mutation biases to the CDR predicted by our models. Finally, it appears that the mutation bias in V genes indeed relates to their long-term survival in actual human repertoires. We observed that resting repertoires of B cells overexpressed V genes that were especially biased toward focused mutation and change in the CDR. This bias in V gene usage was somewhat relaxed at the height of the immune response to a vaccine, presumably because of the need for a wider diversity in a primary response. However, older patients did not retain this flexibility and were biased toward using only highly skewed V genes at all stages of their response.


Asunto(s)
Inmunidad Adaptativa/genética , Linfocitos B/inmunología , Región Variable de Inmunoglobulina/genética , Receptores de Antígenos de Linfocitos B/genética , Hipermutación Somática de Inmunoglobulina/genética , Inmunidad Adaptativa/inmunología , Envejecimiento/inmunología , Afinidad de Anticuerpos/genética , Afinidad de Anticuerpos/inmunología , Linfocitos B/citología , Regiones Determinantes de Complementariedad/genética , Genes de Inmunoglobulinas , Humanos , Cadenas Pesadas de Inmunoglobulina/genética , Región Variable de Inmunoglobulina/inmunología , Mutación , Receptores de Antígenos de Linfocitos T/inmunología , Hipermutación Somática de Inmunoglobulina/inmunología
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