Benjamin Lopez

Specific Polysaccharide Antibody Deficiency Revealed by Severe Bacterial Infections in Adulthood: A Report on 11 Cases

We report on 11 cases of specific polysaccharide antibody deficiency (SPAD) revealed in adulthood by severe infections with encapsulated bacteria. Given that immunoglobulin replacement therapy can effectively prevent the recurrence of bacterial infections in this context, SPAD should be considered once other antibody deficiencies have been ruled out.

A plea for thoracoscopic resection of solitary pulmonary nodule in cancer patients

BackgroundSolitary pulmonary nodules (SPN) are frequently detected in cancer patients. These lesions are often considered as pulmonary metastases and increasingly treated by non-surgical techniques without histological confirmation. The aim of this study is to determine the histological nature of SPN resected by thoracoscopy and to identify risk factors of malignancy.MethodsSingle-institution retrospective analysis of all consecutive patients with previously known malignancies who underwent thoracoscopic resection of SPN with unknown diagnosis between 2001 and 2014.ResultsOne hundred and forty cancer patients underwent thoracoscopic resection of a SPN. The resected SPN was benign in 34 patients (24.3%) and malignant in 106 patients. The latter were metastasis in 70 patients (50%) and a primary lung cancer in 36 patients (25.7%). Upon univariate analysis, malignancy was significantly associated with age >60xa0years, disease-free interval ≥24xa0months, SPN size >8xa0mm, upper lobe localization and SUVmaxxa0>xa02.5 on PET-CT. Upon multivariate analysis, upper lobe localization and SUVmaxxa0>xa02.5 were associated with malignancy. Smoking was significantly associated with SPN containing primary lung cancer.ConclusionIn this series, only 50% of SPN in patients with known malignant disease were pulmonary metastases and 25% had a newly diagnosed NSCLC. Smoking was associated with primary lung cancer but no other predictor was found to allow the distinction between pulmonary metastasis and lung cancer. These results endorse the need of histological confirmation of SPN in patients with previous malignancies to avoid diagnostic uncertainty and suboptimal treatments.

Value of the Overall Pneumococcal Polysaccharide Response in the Diagnosis of Primary Humoral Immunodeficiencies

Background An overall response assay [OVA, based on a 23-valent pneumococcal polysaccharide vaccine (PPV23)] is widely used to screen for anti-pneumococcal antibodies. Given the heterogeneity of response from one polysaccharide (PS) to another, a World Health Organization-standardized serotype-specific enzyme-linked immunosorbent assay (SSA) is considered to be the only reliable method for testing anti-PS antibody responses in individuals with suspected primary immunodeficiencies (PIDs). Objective To evaluate the OVA relative to the reference SSA. Methods Serum samples of adult patients referred for a suspected PID were collected before and then 4–8u2009weeks after immunization with PPV23. The anti-pneumococcal response was systematically assessed with an SSA (7–16 serotypes) and interpreted according to the American Academy of Asthma, Allergy and Immunology’s current guidelines. We used receiver operating characteristic curves and agreement indices to assess the OVA’s diagnostic value in a first cohort. In order to validate these findings, a second (validation) cohort was then prospectively included. Results Sixty-two adult patients were included, and 42 (67.7%) were defined as poor responders according to the SSA. Only the post-immunization titer in the OVA was able to correctly identify poor responders; a titer below 110u2009mg/L gave a positive predictive value of 100% [identifying 24 (57.1%) of the 42 poor responders], and similar levels of diagnostic performance were observed in the validation cohort. The pre-vaccination antibody titer, the post/pre-vaccination antibody titer ratio and a post-vaccination titer above 110u2009mg/L in the OVA were not predictive of the response in the SSA. Conclusion A post-vaccination antibody titer below 110u2009mg/L in the OVA was constantly associated with a poor PPV23 response using the SSA. In all other cases, SSA is the only reliable method for assessing diagnostic vaccination with PPV23.

Harvest technique for pedicled intrathoracic transposition of pectoralis major muscle.

Residual upper pleural spaces after subtotal pulmonary resection continues to pose great challenge for the thoracic surgeon. Although not all residual spaces deserve surgical attention, only in special situation (empyema with or without bronchopleural fistula). It increases morbidity, mortality, hospital stays, and costs. Transposition of extrathoracic muscle flaps has been the cornerstone of treatment of this complication. Sometimes use of latissimus or serratus muscle might have been compromised by the incision for the original operation. In this situation the pectoralis major muscle flap (PMF) can be used successfully to reach and obliterate upper residual pleural space by anterior approach. The technique has never been specifically described before in the literature. We describe our technique for mobilization of PMF by anterior approach to obliterate residual upper space after major pulmonary resections.

Intratubular amyloid in light chain cast nephropathy is a risk factor for systemic light chain amyloidosis

Light chain cast nephropathy is the most common form of kidney disease in patients with multiple myeloma. Light chain casts may occasionally show amyloid staining properties, that is, green birefringence after Congo red staining. The frequency and clinical significance of this intratubular amyloid are poorly understood. Here, we retrospectively assessed the clinicopathological features of 60 patients with histologically proven light chain cast nephropathy with a specific emphasis on intratubular amyloid, especially, its association with extrarenal systemic light chain amyloidosis. We found intratubular amyloid in 17 cases (17/60, 28%) and it was more frequent in patients with λ light chain gammopathy (13/17 in the intratubular amyloid group vs 19/43 in the no intratubular amyloid group, P=0.02). Pathological examination of extrarenal specimens showed that intratubular amyloid was significantly associated with the occurrence of systemic light chain amyloidosis (5/13 in the intratubular amyloid group vs 0/30 in the no intratubular amyloid group, P=0.001). Our results indicate that first, intratubular amyloid is not a rare finding in kidney biopsies of patients with light chain cast nephropathy, and, second, it reflects an amyloidogenic capacity of light chains that can manifest as systemic light chain amyloidosis. Thus, intratubular amyloid should be systematically screened for in kidney biopsies from patients with light chain cast nephropathy and, if detected, should prompt a work-up for associated systemic light chain amyloidosis.

Immunoglobulin G (IgG) and IgG subclass reference intervals in children, using Optilite® reagents

Abstract Background: Immunoglobulin G (IgG) and IgG subclass assays are indicated in patients with suspected primary immunodeficiency (PID). Commercially available assays for IgG subclass determination are calibrated against various preparations, and so specific reference values are required for each of them. Using Optilite® reagents from The Binding Site Group Ltd., we sought to determine the pediatric IgG and IgG subclass reference intervals with respect to the ERM-DA470k certified reference material. Methods: Levels of IgG and IgG subclasses were analyzed in serum samples collected from a large cohort of PID-free children and adolescents. Reference intervals were calculated for previously published age groups (6–12 months, 12–18 months, 18 months–2 years, 2–3 years, 3–4 years, 4–6 years, 6–9 years, 9–12 years and 12–18 years), according to the Clinical and Laboratory Standards Institute’s C28-A3c protocol. Results: A total of 456 serum samples were analyzed. The correlation between the total IgG and the sum of the IgG subclasses was good (r2=0.96). No statistically significant gender-specific differences were observed. Our results for the changes over time in IgG and IgG subclass levels are consistent with previous reports. The differences between our lower/upper reference limits and those in the literature are probably due to variations in calibration. Conclusions: Our present results provide a reliable basis for the diagnosis of PIDs in childhood and for the accreditation of laboratories using Optilite® immunoturbidimetric reagents for IgG subclass measurement. Laboratory scientists and clinicians should be aware of the need for manufacturer-specific IgG subclass reference intervals.

Influence du dosage pondéral des immunoglobulines sériques sur la sérologie JC

Introduction nL’etude BIONAT montrait la baisse des taux d’immunoglobulines (Ig) G sous natalizumab. Un patient considere finalement faussement seronegatif pour le virus JC en raison de son hypogammaglobulinemie a presente une LEMP. nObjectifs nEvaluer l’impact du dosage ponderal des IgG sur la serologie JC a partir de l’ensemble des dosages ponderaux des Ig et des immunophenotypages lymphocytaires des patients traites par natalizumab pour une. nPatients et methodes nNous avons repris les donnees biologiques des patients traites par natalizumab au CHRU de Lille entre avril 2007xa0et novembre 2015. Les donnees de la serologie quantitative JC etaient issues du test ELISA de 2nde generation. Les dosages ponderaux des Ig et les immunophenotypages lymphocytaires etaient realises par le laboratoire du CHRU de Lille. L’evolution des taux d’IgG et M et de l’index JC au cours du temps sous traitement etait etudiee par des modeles multivaries de regression lineaire par morceaux. nResultats nL’analyse a porte sur 1419xa0dosages couples d’index JC et de dosage ponderal des Ig sur 348xa0patients. Il existait une diminution significative du taux d’IgG lors des 6xa0premiers mois de traitement (pxa0<xa00,001). Au-dela, l’effet n’etait pas significatif. Au cours du suivi, 74xa0patients ont eu un dosage ponderal inferieur a 6,9xa0g/L sous natalizumab. Il n’existait aucune correlation significative entre la serologie JC virus et le dosage ponderal des IgG. nDiscussion nL’absence de correlation entre le taux d’IgG et l’index JC peut etre lie au faible nombre de patients ayant des taux anormalement bas d’IgG dans notre population. Cependant la baisse significative des IgG sous natalizumab notamment au debut du traitement doit faire coupler la serologie et l’index JC avec le dosage ponderal des immunoglobulines pour ne pas meconnaitre un faux negatif. nConclusion nNous n’avons pas demontre de lien entre l’index JC virus et le taux d’immunoglobuline G.

Results of celiac trunk stenting during fenestrated or branched aortic endografting

BACKGROUNDnEndovascular repair of aortic aneurysms involving the visceral segment of the aorta often requires placement of a covered bridging stent in the celiac axis (CA). The median arcuate ligament (MAL) is a fibrous arch that unites the diaphragmatic crura on either side of the aortic hiatus. The ligament may compress and distort the celiac artery and result in difficult cannulation, or stenosis and occlusion of the vessel. This study evaluated the influence of the MAL compression on the technical success and the patency of the celiac artery after branched and fenestrated endovascular aortic repair.nnnMETHODSnWe retrospectively analyzed a cohort of consecutive patients treated electively for complex aneurysms with branched and fenestrated endovascular aortic repair between January 2007 and April 2014. All data were collected prospectively. Analysis of preoperative computed tomography angiography on a three-dimensional workstation determined the presence of MAL compression. Patency of the CA bridging stent was assessed during follow-up by computed tomography angiography and duplex ultrasound evaluation. Statistical analysis was performed to compare the outcomes of patients with MAL (MAL+) and without MAL (MAL-) compression.nnnRESULTSnOf 315 patients treated for aortic disease involving the visceral segment during the study period, 113 had endografts designed with a branch (nxa0= 57) or fenestration (nxa0= 56) for the CA. In 45 patients (39.8%), asymptomatic compression of the CA by the MAL was depicted (MAL+). Complex endovascular techniques were required in this group to access the CA in 16 (14.2%) patients (vs none in the MAL- group; Pxa0= .003), which lead to a failed bridging stent implantation in seven patients (6.2%). Increased operative time and dose area product were observed in the MAL+ group, but this did not reach statistical significance. In the MAL+ group, no thrombosis of the CA bridging stents were observed during follow-up; an external compression of the CA bridging stent was depicted in six patients but without hemodynamic effect on duplex ultrasound imaging. In the MAL- group, one CA bridging stent occlusion occurred owing to an embolus from a cardiac source.nnnCONCLUSIONSnMAL compression is associated with good celiac trunk bridging stent patency during follow-up, but with axa0higher rate of technical difficulties and failed bridging stent implantation during the procedure.