RESUMO
Keloid disease (KD) is a common abnormal cutaneous fibrotic disorder of unknown aetiopathogenesis. KD is reported to have a strong genetic component as it is often familial and has a high incidence in certain ethnicities, in particular those of Afro-Caribbean origin. Genetic risk factors combined with aberrant lesional inflammatory responses point to the human leukocyte antigen (HLA) system as a viable target for investigating disease aetiology. Sequence specific primer polymerase chain reaction with allele sequencing was used to determine HLA-DQA1 and DQB1 allele frequencies (AF) for 165 KD patients and 119 healthy controls of black Jamaican Afro-Caribbean origin. HLA class I alleles A*01, A*03, A*25, B*07 and Cw*08:02, previously identified as KD associated in a different ethnicity, were also analysed. Allele sequencing confirmed typing accuracy but no statistically significant differences in AF were identified between KD patients and controls. Furthermore, KD subgroups including patient gender, family history and multiple- or single-site scarring did not show significant allele-disease associations.
Assuntos
População Negra , Etnicidade/genética , Antígenos HLA-D/genética , Antígenos de Histocompatibilidade Classe I/genética , Queloide/genética , Dermatopatias Metabólicas/genética , Adulto , Alelos , Feminino , Predisposição Genética para Doença , Cadeias alfa de HLA-DQ/genética , Cadeias beta de HLA-DQ/genética , Humanos , Queloide/etnologia , Queloide/imunologia , Masculino , Prevalência , Dermatopatias Metabólicas/etnologia , Dermatopatias Metabólicas/imunologia , Adulto JovemRESUMO
BACKGROUND: Keloid disease (KD) is a fibroproliferative dermal tumour of unknown aetiology. The high incidence of familial clustering in KD, its prevalence in certain races and its concordance in identical twins suggest a strong genetic predisposition to keloid formation. The highest incidence of keloids is found in black populations, where the incidence has been estimated to be up to 16%. The most polymorphic genetic system in vertebrates is the major histocompatibility complex (MHC) also known as the human leucocyte antigen (HLA) system. The MHC has been shown to be strongly associated with numerous conditions. Of particular relevance is the association of DR2 with dermal fibrotic diseases including sarcoidosis and systemic sclerosis. AIMS: To investigate the aetiology of KD and the potential involvement of the MHC. METHODS: We compared the HLA-DRB1 phenotype frequencies of Afro-Caribbean patients of Jamaican origin with keloid scars against those seen in a control population of the same ethnicity (n = 121; mean age 34.8 years, range 14-88). In total, 180 keloid cases of Afro-Caribbean origin, recruited from Kingston, Jamaica, were evaluated in the study (mean age 29.7 years, range 2-90 years). HLA-DRB1 alleles were determined in all participants using a semiautomated typing system of reverse hybridization PCR with sequence-specific oligonucleotide probes. HLA-DRB1* phenotype frequencies were established in the Jamaican Afro-Caribbean population and comparisons made between cases and controls. Furthermore, the influence of multiple vs. single lesions, patient gender and family history were also investigated. RESULTS: Differences were observed between the disease and control cohorts although none was significant. CONCLUSIONS: This study does not support an association between HLA-DRB1* alleles and susceptibility to keloid in people of Afro-Caribbean origin.
Assuntos
População Negra/genética , Antígenos HLA-DR/genética , Queloide/genética , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Estudos de Casos e Controles , Criança , Pré-Escolar , Feminino , Predisposição Genética para Doença/genética , Cadeias HLA-DRB1 , Humanos , Jamaica , Masculino , Pessoa de Meia-Idade , Fenótipo , Reação em Cadeia da Polimerase , Cicatrização/genética , Adulto JovemRESUMO
By examining the keloid scars of 211 Afrocaribbean patients presenting to the Plastic Surgery unit in Kingston, Jamaica, we have described site-specific morphologies of scarring; keloid disease is not a homogenous biological entity. All cases conformed to clinical criteria for diagnosis of keloid scarring: 369 keloid scars were present in 137 females (2-83 years; mean 29.6 years; SD+/-14.9 years) and 74 males (5-90 years, mean 29.5 years; SD+/-15.0 years). Morphologies were specific to each anatomical site: trunk scars (n=45,12.1%) were geometrically shaped with clear margins or irregular in outline, surface and margin; back single scars were well-demarcated botryoid but multiple scars were butterfly-shaped, spheroidal and irregular; chest scars (n=72,20.1%) were butterfly or nonbutterfly shaped found most commonly in the midsternal line; upper limb scars (n=57,15.3%) mostly in the deltoid region (propeller shaped) or elsewhere nodular, linear to irregular; ear (n=85,23%) commonest site being the lobe, having reniform to bulbous shape; face and neck (n=60,16.2%) scars were firm nodular to hard; posterior auricular scars were either horizontal and oblong-shaped or vertical and reniform in outline; scalp scars (n=11,2.8%) were commonest in the occipital area varying from small papules to large plaques; lower limb scars (n=39,10.5%) varied from propeller, butterfly, petalloid to dum-bell-shaped. Three plantar and eight pubic keloids were rare findings. Recognition of different morphological phenotypes is necessary in understanding genotypic predisposition and aiding diagnosis, treatment and prognosis of keloid scars.
Assuntos
Queloide/patologia , Adolescente , Adulto , Idoso , População Negra , Criança , Pré-Escolar , Inglaterra , Feminino , Humanos , Jamaica/etnologia , Queloide/etnologia , Masculino , Pessoa de Meia-Idade , Especificidade de ÓrgãosRESUMO
Conscious intravenous sedation is a safe alternative method to general anaesthesia. We have used a technique of continuously titrated, as opposed to incremental boluses of, intravenous or intramuscular midazolam for conscious sedation, with tumescent adrenaline-lignocaine solution for local anaesthesia, routinely in 421 plastic surgical procedures between 1997 and 2000. All patients were American Society of Anesthesiologists (ASA) class I or II. Conscious sedation was administered through our protocol of continuously titrated doses of midazolam in dextrose saline. The operative field was injected subcutaneously with varying volumes of diluted lignocaine and adrenaline, depending on the anatomical region. Preoperative sedation was administered 1 h before the procedure in the form of an intramuscular injection of pethidine and promethazine (Phenergan). Intraoperatively, a subset of patients received up to four divided diluted doses of pethidine. A preoperative 4 h starvation period pronounced the effect of the sedative. No intraoperative conversions to general anaesthesia were needed, and no sedation complications occurred. No unplanned re-admissions secondary to nausea, prolonged drowsiness or pain were required. All patients who were treated using this technique had an uneventful postoperative course. Hospital stay was substantially shorter than following general anaesthesia, which provided a significant reduction in medical-care expenses and a faster return to work. In conclusion, conscious sedation administered by titrated intravenous midazolam is a well-tolerated, safe, consistent, predictable and effective anaesthetic choice for a variety of plastic surgical procedures, many of which would commonly be performed under general anaesthesia.