RESUMO
BACKGROUND: The data referring to the value of direct immunofluorescence on formalin-fixed, paraffin-embedded tissue (IF-Paraffin) in the diagnosis of renal diseases is controversial. The aim of this study was to investigate whether renal biopsies evaluated by routine immunofluorescence on frozen tissue (IF-Frozen) would yield adequate findings to confirm diagnoses when the IF-Paraffin technique was applied. METHODS: To show immunoglobulins, complement components, and light chains, 55 native renal biopsies were subjected to IF-Paraffin and IF-Frozen staining techniques. The intensity of the staining was compared, and the sensitivity and specificity were calculated. RESULTS: The IF-Paraffin technique showed a sensitivity of 89%, 81%, 86%, 30%, 71%, 60%, and 77% for IgG, IgM, IgA, C1q, C3, κ, and λ, respectively, whereas specificity was 91%, 100%, 100%, 96%, 94%, 98%, and 100%. It showed diagnostic findings in 87% of cases. Compared to cases that had both IF-Paraffin and IF-Frozen staining techniques, 43 of 55 showed either equal intensity for the diagnostic immunoglobulin/complement or a little difference. CONCLUSIONS: Direct immunofluorescence on formalin-fixed, paraffin-embedded sections cannot replace immunofluorescence on frozen sections in the assessment of renal biopsies, but may be a "salvage technique" when frozen tissue is insufficient or unavailable and must be interpreted with great caution.
RESUMO
This study tested whether interleukin-6 (IL-6) and interferon-gamma (INF-γ) levels, as well as lipid profile, are associated with suicide attempts in adult patients with major depressive disorder (MDD), after controlling for related confounding factors. Plasma levels of IL-6 and INF-γ and lipid profile, including total cholesterol (TC), triglycerides (TGs), low-density lipoproteins (LDLs), and high-density lipoproteins, were measured in 60 patients meeting criteria of the fifth version of the Diagnostic and Statistical Manual of Mental Disorders for Major Depression (22 patients who attempted suicide and 38 patients who did not attempt suicide) and 30 healthy controls. Study participants were evaluated using the Hamilton Depression Rating Scale and the Beck's Suicidal Ideation Scale. Based on univariate analyses, IL-6, INF-γ, and TG plasma levels were significantly higher in both groups of depressed patients than healthy controls (P < 0.05), whereas TC and LDLs of patients who attempted suicide were significantly lower than patients who did not attempt suicide and healthy controls (P < 0.05). After adjusting for potential confounders, TC and LDLs were still significantly lower in patients who attempted suicide. With the exception of TC and LDLs, our findings do not support the hypothesis that IL-6 and INF-γ levels and lipid profile are associated with suicide attempts in adult patients with MDD. Identifying effective biological markers in patients who attempt suicide remains a challenge for future research.
