RESUMO
Objectives: Clinical decision making depends mostly on appropriate application of numerical pathology reports from laboratory results, interpreted by comparison with reference intervals. We determined serum reference intervals of micronutrients, vitamins, and detectable interleukins among healthy adults in South-Western Nigeria. Design and methods: This prospective study used a priori selection approach in blood-donors. They were screened for conditions that could elicit cytokine production.Serum micronutrients were assayed using Atomic Absorption Spectrophotometry; interleukins and vitamins by high Performance Liquid Chromatography. The reference intervals (RIs) were estimated at 2.5th percentile and 97.5th percentile. Results: One hundred and eighteen (118) apparently healthy subjects, aged 18-56 years; 113 (95.8%) being 18-44years, and 5 (4.2%): 45-56 years; mostly males, 13 (11.02%) females, all Africans of Yoruba ethnicity.Estimated reference limits were: Zinc: 9.49-20.54 µmol/L, Selenium: 0.50-1.11 µmol/L, Copper: 13.86-27.97 µmol/L, Iron: 14.19-32.07 µmol/L, Manganese: 6.24-16.37 nmol/L; Magnesium: 0.78-1.62 mmol/L.Vitamins: A-1.08-2.39 µmol/L; D: 59.89-164.42 µmol/L; E: 7.13-19.45 µmol/L; K: 0.16-0.42 nmol/L; B1: 74.09-201.56 nmol/L; B6: 0.12-0.29 nmol/L; B12: 155.55-407.96 pmol/L; C: 47.74-112.99 µmol/L.Detected interleukins (IL-1 to IL-18): IL-1: 0.58-1.24 ng/L, IL-2: 0.09-0.18 ng/L, IL-3: 0.39-0.89 ng/L, IL-4: 0.27-0.58 ng/L, .to IL-18: 0.74-1.56 ng/L. Conclusions: The RI derived from this study for serum micronutrient, vitamin and interleukin concentrations are the first published for our population. They are in general agreement with those published from other geographical climes but there are differences at the lower and upper limits of the RI. The study reinforces the importance of deriving RI for the population that a clinical laboratory will serve.
RESUMO
BACKGROUND: Cachexia is usually associated with elevated serum interleukin-6 (IL.6) as it stimulates the breakdown of muscle proteins and promotes wasting. OBJECTIVE: A case-control study to evaluate the relationship between weight loss, facial fat loss, and IL-6 in antiretroviral-naïve and treated participants living with HIV/AIDS. METHODS: IL-6 was assayed by High performance liquid chromatography (HPLC) in 97 in consecutive newly diagnosed antiretroviral-naive (ART-naïve) people living with HIV/AIDS (age ≥18 years); and 118 consecutive, age-matched participants currently on Highly Active Antiretroviral Therapy (HAART), using age as a criterion. In the treated group, 78 (66.7%) subjects were on zidovudine, lamivudine with nevirapine (Z+L+N); 27(23.1%) on tenofovir, lamivudine with emtricitabine (T+L+E); 5(4.3%) on zidovudine, lamivudine with emtricitabine (Z+L+E); 4(3.4%) on zidovudine, lamivudine with tenofovir (Z+L+T); 2(1.7%) on lamivudine, tenofovir with nevirapine (L+T+N); 1(0.9%) on tenofovir, zidovudine, emtricitabine (Z+T+E). RESULTS: A total of 215 participants: 97 ART-naive and 118 HAART-treated, age-matched subjects (40.3±9.6 versus 42.7±10.20years, p=0.08). The mean IL-6 was significantly higher in naïve than treated (0.69±0.04 versus 0.66±0.04 pg/ml, p =0.002). In all, 73 subjects experienced weight loss, 56(76.7%) naive, 17(23.3%) treated, p <0.0001, with significantly higher IL-6 in those with weight loss (0.69±0.05 versus 0.67±0.05pg/ml, p= 0.047). Fifty-eight (27.0%) subjects experienced facial fat loss, 49 (84.5%) naïve, and 9 (15.5%) treated, p <0.0001, with significantly higher IL-6 in those with facial fat loss (0.7 ± 0.05 versus 0.67±0.05pg/ml, p= 0.0001). Negative correlation exists between IL-6 and CD4+ count (r=-0.141, p=0.041). In logistic regression, independent predictors of weight loss include: IL-6 (Adjusted Odds Ratio, aOR 1.3, 95%CI 0·1-2·6, p=0.047); HIV duration (aOR 11.6, p <0.0001); AIDS-defining illness (aOR 3.5, p <0.0001); CD4+ count (aOR 3.2, p=0.004); HAART status (aOR 2.7, p<0.0001). CONCLUSION: HIV infection is associated with elevation of serum interleukin-6, which likely contributes to weight and facial fat loss among the treatment-naïve participants; while HAART is associated with suppressed IL-6 levels, thereby ameliorating weight and facial fat loss. Inverse relationship exists between serum IL-6 and CD4+ count; serum IL-6 could differentiate between mild- to moderate and severe immunosuppressive states.