Felicia Stefania Falvella

Article Improving D-dimer testing appropriateness by controlling periodicity of retesting: prevention is better than cure was published on May 6, 2022 in the journal Clinical Chemistry and Laboratory Medicine (CCLM) (volume 0, issue 0).

Dear Editor,We thank La Gioia for the interest in our experience and for providing some further suggestions for improving the approach to spurious elevations of mean corpuscular haemoglobin concent...

Cold agglutinins (CA) in blood may cause false reduction in red blood cell (RBC) count and false increases of RBC indices, such as mean corpuscular haemoglobin concentration (MCHC). Preheating at 37 °C for 2 h is used to overcome this problem. We previously proposed the integration in a total laboratory automation (TLA) setting of a customized reflex test in the presence of MCHC >385 g/L for identifying spurious elevations due to CA. Here, we prospectively evaluate this approach after its introduction in our clinical practice. We evaluated 73 consecutive blood samples from 34 adult patients. Short heating (<1 min) at 41 °C using the reticulocyte channel of Sysmex XN-9000 platform was followed by calculation of optical parameters by the instrument software to ensure quick solution of the CA-dependent problems. After the reflex test in the reticulocyte channel, MCHC dropped below 385 g/L in 50 samples. The reflex markedly corrected the RBC number in eight samples obtained from three patients with CA condition. Two samples from markedly anaemic patients had low blood haemoglobin and RBC count before and after reflex. The remaining 13 samples were obtained from 12 patients, most of whom were on antiretroviral therapy or suffered severe electrolyte disorders, known conditions associated to increased MCHC. The implementation of the proposed automatic reflex by reticulocyte channel on the Sysmex XN-9000 platform in a TLA setting may solve the problem of spuriously high MCHC due to RBC agglutination for CA in a few minutes instead of waiting hours for sample preheating.

Nevirapine has been used as antiretroviral agent since early ‘90. Although nevirapine is not currently recommended in initial anti-HIV regimens, its use remains consistent in a certain number of HIV-1-positive subjects. Thus, our aim was to determine clinical and genetic factors involved in the development of severe nevirapine induced liver toxicity. We retrospectively analyzed all HIV positive patients who were followed at the Infectious Diseases Unit, DIBIC Luigi Sacco, University of Milan from May 2011 to December 2015. All patients treated with nevirapine who underwent a genotyping for the functional variants mapping into ABCB1, CYP2B6, CYP3A4 and CYP3A5 genes were included in the analysis. Severe hepatotoxicity was defined as ACTG grade 3–4 AST/ALT increase during the first three months of nevirapine treatment. The causality assessment between NVP exposure and drug-induced liver injury was performed by using the updated Roussel Uclaf Causality Assessment Methods. Hardy Weinberg equilibrium was tested by χ2 test. A multivariable logistic regression model was constructed using a backward elimination method. Three hundred and sixty-two patients were included in the analysis, of which 8 (2.2%) experienced a severe liver toxicity. We observed no differences between patients with and without liver toxicity as regards gender, ethnicity, age and immune-virological status. A higher prevalence of HCV coinfection (75.0% vs 30.2%; p = .0013) and higher baseline AST (58 IU/L vs 26 IU/L; p = 0.041) and ALT (82 IU/L vs 27 IU/L; p = 0.047) median levels were observed in patients with liver toxicity vs those without toxicity. The genotypes CT/TT at ABCB1 rs1045642 single nucleotide polymorphism (SNP), showed a protective effect for liver toxicity when compared with genotype CC (OR = 0.18, 95%CI 0.04–0.76; p = 0.020) in univariate analysis. In the multivariate model, HCV coinfection was independently associated with higher risk of developing liver toxicity (aOR = 8.00, 95%CI 1.27–50.29; p = 0.027), whereas ABCB1 rs1045642 CT/TT genotypes (aOR = 0.10, 95%CI 0.02–0.47; p = 0.004) was associated with a lower risk. According to our findings HCV coinfection and ABCB1 rs1045642 SNP represent independent determinants of severe liver toxicity related to nevirapine. This genetic evaluation could be included as toxicity assessment in HIV-1-positive subjects treated with nevirapine.

Tenofovir (TDF) is one of the most widely used antiretroviral drug. Despite the high degree of tolerability a small percentage of patients experienced alteration in tubular function during TDF use. Intracellular TDF disposition is regulated by ATP-binding cassette (ABC) drug efflux transporters and, a reduced transport activity may be implicated in accumulation of TDF into the cells. The aim of our study was to assess the major determinants of TDF associated tubular dysfunction (KTD) in a real-life setting including the usefulness of single-nucleotide polymorphisms (SNPs) mapping into ABCC2, ABCC4 and ABCC10 genes. We retrospectively analyzed all HIV positive patients who were followed at the Infectious Diseases Unit, DIBIC Luigi Sacco, University of Milan from April 2013 to June 2016. All patients treated with TDF who underwent a genotypization for the functional variants mapping in ABCC2 rs717620 (−24 C > T), ABCC4 rs1751034 (3463 A > G) and ABCC10 rs2125739 (T > C) were evaluated. KTD was defined as the presence of urine phosphate wasting and/or proteinuria at 24 h urine analysis. One hundred fifty-eight patients were genotyped, of which 42 (26.6%) experienced signs of KTD. No statistical significant differences were observed among patients with or without KTD regarding age, gender, ethnicity and comorbidities (hypertension and diabetes). The percentage of patients with KTD was higher among those with “GG” genotype at rs1751034 of ABCC4 compared to patients without KTD [6 (14.3%) vs 4 (3.5%), p = 0.01]. No statistical significant differences were observed regarding the distribution of ABCC2 and ABCC10 SNPs. Carriers of “G” allele in homozygous status at rs1751034 of ABCC4 showed a significant association with KTD (Odds Ratio 4.67, 95% CI 1.25–17.46, p = 0.02) in bivariate analysis, but this association was lost in multivariable analysis. A significant association between bone diseases and KTD was observed (Odds Ratio 3.178, 95%CI 1.529–6.603, p = 0.002). According to our results ABCC4 rs1751034 could be a genetic determinant of KTD; however validation studies are needed for therapy personalization. Noteworthy, a strong association between bone disease and KTD was also observed.

Article Pharmacogenetics-based optimisation of atazanavir treatment: potential role of new genetic predictors was published on June 1, 2017 in the journal Drug Metabolism and Personalized Therapy (volume 32, issue 2).