Detection of M2-Type Anti-Mitochondrial Autoantibodies against Specific Subunits in the Diagnosis of Primary Biliary Cholangitis in Patients with Discordant Results

BACKGROUND

M2-type anti-mitochondrial autoantibodies are considered the hallmark of primary biliary cholangitis and are directed mainly against the E2 subunits of the 2-oxo acid dehydrogenase complex enzymes (PDC, BCOADC and OGDC). The aim of this study was to determine whether a Dot-blot that includes these E2 subunits separately could confirm the results of methods with non-separated subunits in patients with low positive or discordant results between techniques.

METHODS

Sera of 24 patients with low positive or discordant results and of 10 patients with clear positive results by non-separated subunits methods were analyzed by Dot-blot with separated subunits.

RESULTS

Autoantibodies against E2 subunits of PDC, BCOADC or OGDC were detected in all patients, except in one case from the low positive or discordant results group, by Dot-blot with separated subunits.

CONCLUSIONS

It would be advisable to use methods that include the three E2 subunits, and a Dot-blot with separated subunits could confirm doubtful cases by non-separated assays.

CoVITEST: A Fast and Reliable Method to Monitor Anti-SARS-CoV-2 Specific T Cells From Whole Blood

Cellular and humoral immune responses are essential for COVID-19 recovery and protection against SARS-CoV-2 reinfection. To date, the evaluation of SARS-CoV-2 immune protection has mainly focused on antibody detection, generally disregarding the cellular response, or placing it in a secondary position. This phenomenon may be explained by the complex nature of the assays needed to analyze cellular immunity compared with the technically simple and automated detection of antibodies. Nevertheless, a large body of evidence supports the relevance of the T cell's role in protection against SARS-CoV-2, especially in vulnerable individuals with a weakened immune system (such as the population over 65 and patients with immunodeficiencies). Here we propose to use CoVITEST (Covid19 anti-Viral Immunity based on T cells for Evaluation in a Simple Test), a fast, affordable and accessible in-house assay that, together with a diagnostic matrix, allows us to determine those patients who might be protected with SARS-CoV-2-reactive T cells. The method was established using healthy SARS-CoV-2-naïve donors pre- and post-vaccination (n=30), and further validated with convalescent COVID-19 donors (n=51) in a side-by-side comparison with the gold standard IFN-γ ELISpot. We demonstrated that our CoVITEST presented reliable and comparable results to those obtained with the ELISpot technique in a considerably shorter time (less than 8 hours). In conclusion, we present a simple but reliable assay to determine cellular immunity against SARS-CoV-2 that can be used routinely during this pandemic to monitor the immune status in vulnerable patients and thereby adjust their therapeutic approaches. This method might indeed help to optimize and improve decision-making protocols for re-vaccination against SARS-CoV-2, at least for some population subsets.

Non-invasive pressure support ventilation versus conventional oxygen therapy in acute cardiogenic pulmonary oedema: a randomised trial

BACKGROUND

Non-invasive pressure support ventilation (NIPSV) is an effective treatment for acute respiratory failure in patients with chronic obstructive pulmonary disease. We assessed the efficacy of this therapy in acute cardiogenic pulmonary oedema in a randomised comparison with conventional oxygen therapy.

METHODS

40 patients were randomly assigned conventional oxygen therapy or NIPSV supplied by a standard ventilator through a face mask, with adjustment of tidal volume and pressure support in addition to a positive end-expiratory pressure of 5 cm water. Physiological measurements were obtained in the first 2 h and at 3 h, 4 h, and 10 h. The main endpoints were intubation rate and resolution time. Analyses were by intention to treat.

FINDINGS

Three patients were withdrawn on the basis of clinical and chest radiography results. Endotracheal intubation was required in one (5%) of 19 patients assigned NIPSV and in six (33%) of 18 assigned conventional oxygen therapy (p=0.037). Resolution time (defined as a clinical improvement with oxygen saturation of 96% or more and respiratory rate less than 30 breaths/min) was significantly shorter in the NIPSV group (median 30 [IQR 15-53] vs 105 [50-230] min, p=0.002). NIPSV led to a rapid improvement in oxygenation in the first 2 h. There were no differences in hospital length of stay or mortality.

INTERPRETATION

In this study of acute cardiogenic pulmonary oedema, NIPSV was superior to conventional oxygen therapy. Further studies should compare NIPSV with continuous positive airway pressure.

Short-term effects of prone position in critically ill patients with acute respiratory distress syndrome

OBJECTIVE

Changing the position from supine to prone is an emerging strategy to improve gas exchange in patients with the acute respiratory distress syndrome (ARDS). The aim of this study was to evaluate the acute effects on gas exchange, hemodynamics, and respiratory system mechanics of turning critically ill patients with ARDS from supine to prone.

DESIGN

Open, prospective study.

SETTING

General intensive care units.

PATIENTS

23 patients [mean age 56 +/- 17 (SD) years] who met ARDS criteria and had a Lung Injury Score > 2.5 (mean 3.25 +/- 0.3).

INTERVENTIONS

The decision to turn a patient was made using a protocol based on impaired oxygenation despite the use of positive end-expiratory pressure and a fractional inspired oxygen (FIO2) of 1.

MEASUREMENTS AND RESULTS

We measured gas exchange and hemodynamic variables in all patients and in 16 patients calculated respiratory system compliance when they were supine and 60 to 90 min after turning them to a prone position. This latter position was remarkably well tolerated and no clinically relevant complications or events were detected either during turning or while prone. The partial pressure of oxygen in arterial blood (PaO2)/FIO2 ratio improved from 78 +/- 37 mm Hg supine to 115 +/- 31 mm Hg prone (p < 0.001), and intrapulmonary shunt decreased from 43 +/- 11 to 34 +/- 8% (p < 0.001). Cardiac output and other hemodynamic parameters were not affected. Respiratory system compliance slightly improved from 24.7 +/- 10.2 ml/cmH20 supine to 27.8 +/- 13.2 ml/cmH20 prone (p < 0.05). An improvement in PaO2/FIO2 of more than 15% from changing from supine to prone was found in 16 patients (responders). Responders had more hypoxemia (PaO2/FIO2 70 +/- 23 vs 99 +/- 53 mm Hg in non-responders, p < 0.01), more hypercapnia (partial pressure of carbon dioxide in arterial blood (70 +/- 27 vs 64 +/- 9 mm Hg, p < 0.01) and a shorter elapsed time to the onset of ARDS and turning to the prone position (11.8 +/- 16 vs 32.8 +/- 42 days, p < 0.01).

CONCLUSIONS

Turning critically ill, severely hypoxemic patients from the supine to the prone position is a safe and useful therapeutic intervention. Our data suggest that prone positioning should be carried out early in the course of ARDS.

[Gas exchange and hemodynamic effects of nitric oxide inhalation in patients with acute respiratory distress syndrome]

BACKGROUND

To analyze the effects on gas exchange and hemodynamics of nitric oxide inhalation in patients with acute respiratory distress syndrome.

PATIENTS AND METHODS

Prospective study including 16 acute respiratory distress syndrome patients. We analyzed the acute and short-term (5 days) effects of inhaling 5 parts per million (ppm) nitric oxide on gas exchange and hemodynamics.

RESULTS

After nitric oxide inhalation, PaO2/FiO2 ratio changed from 81 +/- 25 to 126 +/- 57 mmHg (p = 0.0001), mean pulmonary artery pressure decreased from 30.1 +/- 8.2 to 27.3 +/- 6.6 mmHg (p = 0.002), intrapulmonary shunt decreased from 44.6 +/- 11% to 34.1 +/- 7.9% (p = 0.002) and cardiac index did not change. Thirteen out of 16 patients (81.2%) presented at least a 20% improvement in PaO2/FiO2 ratio. In the 10 patients treated over 5 consecutive days, we observed that those who improved (increase in PaO2/FiO2 ratio higher than 20% after inhaling 5 ppm nitric oxide) showed a lower cardiac index, a higher mean pulmonary artery pressure and a higher pulmonary vascular resistance index than those who did not: Cl 3.9 +/- 0.81 vs 4.9 +/- 0.81 l/min/m2 (p < 0.001), mean pulmonary artery pressure 32.4 +/- 7 vs 25.3 +/- 4.2 mmHg (p = 0.001), and pulmonary vascular resistance index 421 +/- 199 vs 241 +/- 106 dyn.s.cm5/m2 (p = 0.003). Mean levels of methemoglobin were 1.1 +/- 0.24% (range: 0.4-1.6%), and NO2 concentration was always lower than 100 parts per billion.

CONCLUSIONS

Low doses of inhaled nitric oxide induce a selective pulmonary vasodilatation and significant improvement of oxygenation in the majority of acute respiratory distress syndrome patients, although those with a hyperkinetic hemodynamic status are less likely to improve the oxygenation. These effects are maintained for at least 5 days. We did not observe rebound effects.

Prognostic indexes and mortality in critically ill patients with acute renal failure treated with different dialytic techniques

The objective of this study was to compare the evolution of patients with acute renal failure (ARF) treated conservatively or with different dialytic techniques in an intensive care unit (ICU). From June 1992 to November 1994, 1087 consecutive patients were admitted in our ICU. Two hundred and twenty of these presented with ARF, and were divided into three groups; group I (control group): 156 patients with ARF who did not receive substitutive techniques; group II: 21 patients under intermittent hemodialysis (IHD) or peritoneal dialysis (PD); group III: 43 patients under continuous hemodiafiltration (CHDF). The studied variables were age, etiology of renal failure, requirement of dialysis, type of dialysis, length of ICU and hospital stay, and renal function outcome. APACHE II and SAPS scores were recorded on admission and analyzed for hospital mortality. Chi-square test and the analysis of variance were used for the statistical analysis. Results are presented as mean +/- SD. A p value below 0.05 was considered statistically significant. Although etiology of ARF was multifactorial, we found a high frequency of ARF due to sepsis (56.8%), hypoperfusion (58.7%), and acute tubular necrosis (62.5%). Sepsis and heart failure were clinical conditions associated to a greater mortality. We did not find any statistical difference between the two dialyzed groups for all the studied variables, nor between the three groups regarding APACHE II and hospital stay. Significant differences were found between dialyzed and non-dialyzed patients respect to age, group I: 64.1 +/- 13.6, group II: 56.4 +/- 19.7, and group III: 56.0 +/- 14.1 (p < 0.001), creatinine peak serum levels, group I: 260 +/- 130, group II: 494 +/- 209, and group III: 441 +/- 170 mumol/L (p < 0.0001), and mortality, group I: 46.9%, group II: 66.7%, and group III: 76.2% (p < 0.002). SAPS score showed differences between the control group and the CHDF group 13.9 +/- 4.8 and 16.4 +/- 5.4 (p < 0.007), respectively. The use of dialytic techniques in critically ill ARF patients is associated with greater mortality. Prognostic indexes on admission did not correctly classify our patients with ARF. Continuous hemodiafiltration does not involve greater mortality or length of stay as compared to conventional dialysis.

[Clinical relevance of gram-negative bacteria having inducible chromosomic beta-lactamase at an intensive care unit]

BACKGROUND

The aim of the study was to determine the frequency of third-generation cephalosporins and aztreonam resistance in gram-negative bacteria with inducible chromosomal beta-lactamase (beta Lac-ind) after beta-lactam therapy in the medical-surgical intensive care unit (ICU) at a university-affiliated hospital.

PATIENTS AND METHODS

We studied 34 infections in 29 patients admitted to the ICU. All were infected by strains with beta Lac-ind and all were treated with beta-lactam antibiotics. Susceptibility was determined by disc-diffusion. The beta-lactamase activity of those strains showing constitutive beta-lactamase overproduction were characterized by isoelectrofocusing. When this derepression occurred during the therapy, the strains were compared by genomic macrorestriction (PGFE).

RESULTS

In 29 out of 34 infections the initial strains was susceptible. In 11 cases, the culture were not negativized in spite of their susceptible pattern. In 4 cases there was derepression during therapy. In 5 cases the initial strains were derepressed. The microorganisms isolated more frequently were Pseudomonas aeruginosa (22 cases) and Enterobacter cloacae (5 cases). The beta-lactamase activity detected correspond well with a betaLac-ind. In those cases with derepression during therapy, the initial susceptible strain and the resistant strain were identical by PGFE.