Assessment of the InSiGHT Interpretation Criteria for the Clinical Classification of 24 MLH1 and MSH2 Gene Variants.

Pathogenicity assessment of DNA variants in disease genes to explain their clinical consequences is an integral component of diagnostic molecular testing. The International Society for Gastrointestinal Hereditary Tumors (InSiGHT) has developed specific criteria for the interpretation of mismatch repair (MMR) gene variants. Here, we performed a systematic investigation of 24 MLH1 and MSH2 variants. The assessments were done by analyzing population frequency, segregation, tumor molecular characteristics, RNA effects, protein expression levels, and in vitro MMR activity. Classifications were confirmed for 15 variants and changed for three, and for the first time determined for six novel variants. Overall, based on our results, we propose the introduction of some refinements to the InSiGHT classification rules. The proposed changes have the advantage of homogenizing the InSIGHT interpretation criteria with those set out by the Evidence-based Network for the Interpretation of Germline Mutant Alleles (ENIGMA) consortium for the BRCA1/BRCA2 genes. We also observed that the addition of only few clinical data was sufficient to obtain a more stable classification for variants considered as "likely pathogenic" or "likely nonpathogenic." This shows the importance of obtaining as many as possible points of evidence for variant interpretation, especially from the clinical setting.

New patterns of relapse in multiple myeloma: a case of "light chain escape" in which FLC predicted relapse earlier than urine and serum immunofixation.

Multiple myeloma (MM) is characterized, in about 80% of cases, by the production of monoclonal intact immunoglobulin and more than 95% of them have elevated concentrations of involved (i.e. of the same class of intact immunoglobulin) free light chain (FLC). The introduction of novel therapeutic strategies has changed the natural history of the disease, leading to new manifestations of relapse. Light chain escape (LCE) is a pattern of relapse in which the FLC increase is not accompanied by a concomitant raise of the original monoclonal component (MC). Here we present a case of a 55-year-old man with an IgG kappa MM stage III diagnosed in September 2007. At presentation an IgG kappa MC and urine Bence Jones protein (BJP) kappa were present. Bone marrow biopsy (BMB) showed the presence of 80% monotypic kappa plasma cells (PCs). The patient received bortezomib, thalidomide, dexamethasone before undergoing a double autologous stem cell transplantation (ASCT) in October 2008 and April 2009. In May 2011 he relapsed showing the same pattern of presentation and treatment with lenalidomide and dexamethasone was started. ln May 2013 serum and urine immunofixation and FLC became negative. In September 2014, an increase of kappa FLC was observed, while serum and urine immunofixations remained negative until January 2015, when urine immunofixation became positive. Eventually, in February 2015, serum immunofixation revealed the presence of a free kappa MC. After a new BMB showing 80% of monotypic kappa PCs, a LCE relapse was diagnosed and the patient started the treatment with bendamustine, bortezomib and dexamethasone. In the present case, the increase of kappa FLC has indicated relapse 4 and 5 months earlier than urine and serum IFE, respectively. Our observation confirms that it is advisable to routinely perform FLC or BJP during follow up of MM patients undergoing ASCT and/or treatment with biological drugs to ensure that LCE is not missed.

Hemodialysis with High Cut-Off Hemodialyzers in Patients with Multi-Drug Resistant Gram-Negative Sepsis and Acute Kidney Injury: A Retrospective, Case-Control Study.

BACKGROUND: Hemodialysis with high cut-off continuous veno-venous hemodialyzer (HCO-CVVHD) removes mediators of organ dysfunction during sepsis. This study assessed the clinical effects of HCO-CVVHD as compared to high-flux (HF) membranes during gram-negative sepsis. METHODS: Intensive care unit (ICU), septic patients treated with HCO-CVVHD or HF-CVVHDF for AKI were retrospectively observed (January 2013-December 2014). Mechanical ventilation, vasopressors' requirements, ICU length of stay (LOS) and ICU in-hospital mortality were compared between groups. RESULTS: Sixteen HCO and 8 HF patients were observed. Isolated pathogens included Klebsiella pneumoniae, Acinetobacter baumannii, Escherichia coli and Pseudomonas aeruginosa. Median ratios of days-on-vasopressors and days-on-mechanical ventilation/ICU-LOS were 0.5, 1 and 0.8, 1 for HCO and HF groups (p < 0.03), respectively. ICU-LOS was 16 and 9 days (HCO- and HF-group, p = 0.03). ICU mortality rates were 37.5 and 87.5% for HCO and HF groups, respectively (p = 0.03). No statistical difference was found in in-hospital morality. CONCLUSION: Patients in HCO-CVVHD group spent lesser number of days on vasopressors and mechanical ventilation as a ratio to total ICU-LOS. In the same group, a reduction in ICU mortality was observed.

Role of hemodialysis with high cut-off membranes in a patient with a non-recognized leishmaniasis.

BACKGROUND: We report here a case of a woman affected by fever, weight loss, splenomegaly, and leucopenia associated with trombocytopenia, transferred to the intensive care unit with acute kidney injury and septic shock. METHODS: Patient was treated with high cut-off continuous veno-venous hemodialysis (HCO-CVVHD). RESULTS: During treatment, the patient experienced a stable improvement in the hemodynamic, pulmonary function and tissue perfusion parameters. After 48 h of treatment, significant reductions in SOFA score (from 12, before starting the procedure, to 6) and in serum inflammatory mediators (as IL-6, from 599-568 pg/ml) were observed. Leishmania infection was identified as responsible of the septic condition only 48 h after removing hemodialysis. Antiprotozoal therapy was begun and the patient discharged. CONCLUSIONS: By supporting the renal function and reducing systemic inflammation, HCO-CVVHD could be a useful bridge therapy. This procedure allowed the medical team to gain sufficient time to diagnose the type of infection and begin an etiological therapy.

Routine coagulation testing in Vacutainer® Citrate Plus tubes filled at minimum or optimal volume.

Background Filling of citrate tubes with appropriate amount of blood is essential for obtaining reliable results of coagulation testing. This study aimed to verify whether results of routine coagulation tests are comparable when the new Becton Dickinson Vacutainer® Citrate Plus tubes are filled at minimum or optimal volume. Methods The study population consisted of 133 patients (40 on oral anticoagulant therapy), who had blood collected for routine coagulation testing. Two sequential Vacutainer® Citrate Plus tubes of the same type and lot were drawn. The first tube was collected after a butterfly needle was inserted into the vein, so that the air in the tubing was aspirated into the tube before blood (minimum fill volume), whilst the second was drawn at optimal fill volume. Experiments were repeated using 2.7-mL (n = 86) and 1.8-mL (n = 47) tubes. Results Prothrombin time (PT) and fibrinogen values were slightly but significantly decreased in tubes with minimum than in those with optimal fill volume. The activated partial thromboplastin time (APTT) was slightly prolonged in tubes with minimum than in those with optimal fill volume, but the difference was not statistically significant. An identical trend was noted in separate analyses for the 2.7-mL and 1.8-mL tubes. Spearman's correlations between the two fill volumes were always >0.94 and bias was always within the quality specifications. Conclusions Blood drawing into Vacutainer® Citrate Plus tubes at minimum fill volume does not clinically bias routine coagulation testing.

Effects of fecal sampling on preanalytical and analytical phases in quantitative fecal immunochemical tests for hemoglobin.

BACKGROUND: Information on preanalytical variability is mandatory to bring laboratories up to ISO 15189 requirements. Fecal sampling is greatly affected by lack of harmonization in laboratory medicine. The aims of this study were to obtain information on the devices used for fecal sampling and to explore the effect of different amounts of feces on the results from the fecal immunochemical test for hemoglobin (FIT-Hb). METHODS: Four commercial sample collection devices for quantitative FIT-Hb measurements were investigated. The volume of interest (VOI) of the probes was measured from diameter and geometry. Quantitative measurements of the mass of feces were carried out by gravimetry. The effects of an increased amount of feces on the analytical environment were investigated measuring the Hb values with a single analytical method. RESULTS: VOI was 8.22, 7.1 and 9.44 mm3 for probes that collected a target of 10 mg of feces, and 3.08 mm3 for one probe that targeted 2 mg of feces. The ratio between recovered and target amounts of devices ranged from 56% to 121%. Different changes in the measured Hb values were observed, in adding increasing amounts of feces in commercial buffers. CONCLUSIONS: The amounts of collected materials are related to the design of probes. Three out 4 manufacturers declare the same target amount using different sampling volumes and obtaining different amounts of collected materials. The introduction of a standard probes to reduce preanalytical variability could be an useful step for fecal test harmonization and to fulfill the ISO 15189 requirements.

The frequency of granulocytes with spontaneous somatic mutations: a wide distribution in a normal human population.

Germ-line mutation rate has been regarded classically as a fundamental biological parameter, as it affects the prevalence of genetic disorders and the rate of evolution. Somatic mutation rate is also an important biological parameter, as it may influence the development and/or the course of acquired diseases, particularly of cancer. Estimates of this parameter have been previously obtained in few instances from dermal fibroblasts and lymphoblastoid cells. However, the methodology required has been laborious and did not lend itself to the analysis of large numbers of samples. We have previously shown that the X-linked gene PIG-A, since its product is required for glycosyl-phosphatidylinositol-anchored proteins to become surface bound, is a good sentinel gene for studying somatic mutations. We now show that by this approach we can accurately measure the proportion of PIG-A mutant peripheral blood granulocytes, which we call mutant frequency, ƒ. We found that the results are reproducible, with a variation coefficient (CV) of 45%. Repeat samples from 32 subjects also had a CV of 44%, indicating that ƒ is a relatively stable individual characteristic. From a study of 142 normal subjects we found that log ƒ is a normally distributed variable; ƒ variability spans a 80-fold range, from less than 1×10⁻6 to 37.5×10⁻6, with a median of 4.9×10⁻6. Unlike other techniques commonly employed in population studies, such as comet assay, this method can detect any kind of mutation, including point mutation, as long as it causes functional inactivation of PIG-A gene. Since the test is rapid and requires only a small sample of peripheral blood, this methodology will lend itself to investigating genetic factors that underlie the variation in the somatic mutation rate, as well as environmental factors that may affect it. It will be also possible to test whether ƒ is a determinant of the risk of cancer.

Is green tea a potential trigger for autoimmune hepatitis?

A case of autoimmune liver hepatitis is reported: the onset was triggered by consumption of green tea infusion in a patient taking oral contraceptives and irbesartan. We hypothesize that our patient, carrying genetic variant of hepatic metabolism making her particularly susceptible to oxidative stress, developed an abnormal response to a mild toxic insult, afforded by a combination of agents (oral contraceptives+irbesartan+green tea) that normally would not be able to cause damage. Her particular hepatic metabolism further increased the drugs' concentration, favoring the haptenization of liver proteins, eventually leading to the development of an autoimmune hepatitis.