RESUMEN
BACKGROUND: Viral kinetics impact humoral immune response to HIV; antibody avidity testing helps distinguish recent (<6 months) and long-term HIV infection. This study aims to determine the frequency of recent HIV-1 infection among clients attending ICTC (Integrated Counselling and Testing Centre) using a commercial EIA, to correlate it with a modified in-house avidity assay and to study the impact of ART on anti-HIV-1 antibody maturation. METHODS: Commercial LAg Avidity EIA was used to detect antibody avidity among 117 treatment naïve HIV-1 infected individuals. A second-generation HIV ELISA was modified for in-house antibody avidity testing and cutoff was set based on Receiver Operating Characteristic (ROC) analysis. Archived paired samples from 25 HIV-1 infected individuals before ART and after successful ART; samples from 7 individuals responding to ART and during virological failure were also tested by LAg Avidity EIA. RESULTS: Six individuals (5.1%) were identified as recently infected by a combination of LAg avidity assay and HIV-1 viral load testing. The modified in-house avidity assay demonstrated sensitivity and specificity of 100% and 98.2%, respectively, at AI=0.69 by ROC analysis. Median ODn values of individuals when responding to ART were significantly lower than pre-ART [4.136 (IQR 3.437- 4.827) vs 4.455 (IQR 3.748-5.120), p=0.006] whereas ODn values were higher during virological failure [4.260 (IQR 3.665 - 4.515) vs 2.868 (IQR 2.247 - 3.921), p=0.16]. CONCLUSION: This modified in-house antibody avidity assay is an inexpensive method to detect recent HIV-1 infection. ART demonstrated significant effect on HIV-1 antibody avidity owing to changes in viral kinetics.
Asunto(s)
Antirretrovirales/farmacología , Afinidad de Anticuerpos/inmunología , Formación de Anticuerpos/efectos de los fármacos , Anticuerpos Anti-VIH/inmunología , Infecciones por VIH/diagnóstico , VIH-1 , Antirretrovirales/uso terapéutico , Estudios de Cohortes , Ensayo de Inmunoadsorción Enzimática/normas , Anticuerpos Anti-VIH/sangre , Infecciones por VIH/tratamiento farmacológico , Infecciones por VIH/inmunología , Humanos , Sensibilidad y EspecificidadRESUMEN
Brucellosis, a common zoonosis, is under reported in India despite its endemicity and increased exposure to livestock among the population. This study was conducted to determine the clinical manifestations, antibiotic susceptibility pattern, treatment and outcome of culture confirmed brucellosis. Adult patients with culture confirmed brucellosis who presented to a large teaching hospital in South India between 2009 and 2015 were included. A diagnosis of brucellosis was confirmed on automated culture. Clinical profile, laboratory parameters, drug susceptibility, treatment and outcome were documented by reviewing the medical records. The cohort comprised of 22 patients with mean ± SD age of 42 ± 13 years. Twenty one (95.5%) was male. Thirteen (59%) patients were from rural area and risk of acquisition of brucellosis including occupational exposure or consumption of unpasteurized milk was evident in 16 (72.7%) patients. The mean duration of symptoms before presentation was 54.5 ± 52 days. The commonest clinical presentation was prolonged fever without a definite focus in 18 patients (82%), whereas 2 (9%) patients had osteoarticular involvement and one patient (4.5%) each had genital involvement and endocarditis. Eighteen patients (82%) with uncomplicated brucellosis were treated with aminoglycoside and doxycycline for 6 weeks. There was no relapse or mortality at 18 ± 9 months of follow up. Brucellosis in this cohort had acute or subacute presentation with prolonged fever and bacteremia. High index of clinical suspicion based on significant epidemiological history along with automated blood culture improves the efficiency of diagnosis. Cure with lack of relapse among these cases suggests a combination therapy with doxycycline and aminoglycoside is highly effective for the treatment.