A novel syndrome of silent rhinovirus-associated bronchoalveolitis in children with recurrent wheeze.

BACKGROUND: Rhinovirus (RV) infections trigger wheeze episodes in children. Thus, understanding of the lung inflammatory response to RV in children with wheeze is important. OBJECTIVES: This study sought to examine the associations of RV on bronchoalveolar lavage (BAL) granulocyte patterns and biomarkers of inflammation with age in children with treatment-refractory, recurrent wheeze (n = 616). METHODS: Children underwent BAL to examine viral nucleic acid sequences, bacterial cultures, granulocyte counts, and phlebotomy for both general and type-2 inflammatory markers. RESULTS: Despite the absence of cold symptoms, RV was the most common pathogen detected (30%), and when present, was accompanied by BAL granulocytosis in 75% of children. Compared to children with no BAL pathogens (n = 341), those with RV alone (n = 127) had greater (P < .05) isolated neutrophilia (43% vs 16%), mixed eosinophils and neutrophils (26% vs 11%), and less pauci-granulocytic (27% vs 61%) BAL. Children with RV alone furthermore had biomarkers of active infection with higher total blood neutrophils and serum C-reactive protein, but no differences in blood eosinophils or total IgE. With advancing age, the log odds of BAL RV alone were lower, 0.82 (5th-95th percentile CI: 0.76-0.88; P < .001), but higher, 1.58 (5th-95th percentile CI: 1.01-2.51; P = .04), with high-dose daily corticosteroid treatment. CONCLUSIONS: Children with severe recurrent wheeze often (22%) have a silent syndrome of lung RV infection with granulocytic bronchoalveolitis and elevated systemic markers of inflammation. The syndrome is less prevalent by school age and is not informed by markers of type-2 inflammation. The investigators speculate that dysregulated mucosal innate antiviral immunity is a responsible mechanism.

Pseudomonas aeruginosa infection correlates with high MFI donor-specific antibody development following lung transplantation with consequential graft loss and shortened CLAD-free survival.

BACKGROUND: Donor-specific antibodies (DSAs) are common following lung transplantation (LuTx), yet their role in graft damage is inconclusive. Mean fluorescent intensity (MFI) is the main read-out of DSA diagnostics; however its value is often disregarded when analyzing unwanted post-transplant outcomes such as graft loss or chronic lung allograft dysfunction (CLAD). Here we aim to evaluate an MFI stratification method in these outcomes. METHODS: A cohort of 87 LuTx recipients has been analyzed, in which a cutoff of 8000 MFI has been determined for high MFI based on clinically relevant data. Accordingly, recipients were divided into DSA-negative, DSA-low and DSA-high subgroups. Both graft survival and CLAD-free survival were evaluated. Among factors that may contribute to DSA development we analyzed Pseudomonas aeruginosa (P. aeruginosa) infection in bronchoalveolar lavage (BAL) specimens. RESULTS: High MFI DSAs contributed to clinical antibody-mediated rejection (AMR) and were associated with significantly worse graft (HR: 5.77, p < 0.0001) and CLAD-free survival (HR: 6.47, p = 0.019) compared to low or negative MFI DSA levels. Analysis of BAL specimens revealed a strong correlation between DSA status, P. aeruginosa infection and BAL neutrophilia. DSA-high status and clinical AMR were both independent prognosticators for decreased graft and CLAD-free survival in our multivariate Cox-regression models, whereas BAL neutrophilia was associated with worse graft survival. CONCLUSIONS: P. aeruginosa infection rates are elevated in recipients with a strong DSA response. Our results indicate that the simultaneous interpretation of MFI values and BAL neutrophilia is a feasible approach for risk evaluation and may help clinicians when to initiate DSA desensitization therapy, as early intervention could improve prognosis.

The discovery of novel and potent indazole NLRP3 inhibitors enabled by DNA-encoded library screening.

NLRP3 is an intracellular sensor protein that detects a broad range of danger signals and environmental insults. Its activation results in a protective pro-inflammatory response designed to impair pathogens and repair tissue damage via the formation of the NLRP3 inflammasome. Assembly of the NLRP3 inflammasome leads to caspase 1-dependent secretory release of the pro-inflammatory cytokines IL-1ß and IL-18 as well as to gasdermin d-mediated pyroptotic cell death. Herein, we describe the discovery of a novel indazole series of high affinity, reversible inhibitors of NLRP3 activation through screening of DNA-encoded libraries and the potent lead compound 3 (BAL-0028, IC50 = 25 nM) that was identified directly from the screen. SPR studies showed that compound 3 binds tightly (KD range 104-123 nM) to the NACHT domain of NLRP3. A CADD analysis of the interaction of compound 3 with the NLRP3 NACHT domain proposes a binding site that is distinct from those of ADP and MCC950 and includes specific site interactions. We anticipate that compound 3 (BAL-0028) and other members of this novel indazole class of neutral inhibitors will demonstrate significantly different physical, biochemical, and biological properties compared to NLRP3 inhibitors previously identified.

Differential Gene Expression of SARS-CoV-2 Positive Bronchoalveolar Lavages: A Case Series.

BACKGROUND: Transcriptomic data on bronchoalveolar lavage (BAL) from COVID-19 patients are currently scarce. OBJECTIVES: This case series seeks to characterize the intra-alveolar immunopathology of COVID-19. METHOD: BALs were performed on 14 patients (5 COVID-19, of which 3 mild and 2 largely asymptomatic, 9 controls). Controls included asthma (n = 1), unremarkable BALs (n = 3), infections with respiratory syncytial virus (n = 1), influenza B (n = 1), and infections with other coronaviruses (n = 3). SARS-CoV-2 RNA load was measured by quantitative nucleic acid testing, while the detection of other pathogens was performed by immunofluorescence or multiplex NAT. RESULTS: Gene expression profiling showed 71 significantly downregulated and 5 upregulated transcripts in SARS-CoV-2-positive lavages versus controls. Downregulated transcripts included genes involved in macrophage development, polarization, and crosstalk (LGALS3, MARCO, ERG2, BTK, RAC1, CD83), and genes involved in chemokine signaling and immunometabolism (NUPR1, CEBPB, CEBPA, PECAM1, CCL18, PPARG, ALOX5, ALOX5AP). Upregulated transcripts featured genes involved in NK-T cell signaling (GZMA, GZMH, GNLY, PRF1, CD3G). Patients with mild COVID-19 showed a significant upregulation of genes involved in blood mononuclear cell/leukocyte function (G0S2, ANXA6, FCGR2B, ADORA3), coagulation (von Willebrand factor [VWF]), interferon response (IFRD1, IL12RB2), and a zinc metalloprotease elevated in asthma (CPA3) compared to asymptomatic cases. In-silico comparison of the 5 COVID-19 BAL cases to a published cohort of lethal COVID-19 showed a significant upregulation of "antigen processing and presentation" and "lysosome" pathways in lethal cases. CONCLUSIONS: These data underscore the heterogeneity of immune response in COVID-19. Further studies with a larger dataset are required to gain a better understanding of the hallmarks of SARS-CoV-2 immunological response.

Combination of BAL and Computed Tomography Differentiates Progressive and Non-progressive Fibrotic Lung Diseases.

Rationale: Identifying patients with pulmonary fibrosis (PF) at risk of progression can guide management. Objectives: To explore the utility of combining baseline BAL and computed tomography (CT) in differentiating progressive and nonprogressive PF. Methods: The derivation cohort consisted of incident cases of PF for which BAL was performed as part of a diagnostic workup. A validation cohort was prospectively recruited with identical inclusion criteria. Baseline thoracic CT scans were scored for the extent of fibrosis and usual interstitial pneumonia (UIP) pattern. The BAL lymphocyte proportion was recorded. Annualized FVC decrease of >10% or death within 1 year was used to define disease progression. Multivariable logistic regression identified the determinants of the outcome. The optimum binary thresholds (maximal Wilcoxon rank statistic) at which the extent of fibrosis on CT and the BAL lymphocyte proportion could distinguish disease progression were identified. Measurements and Main Results: BAL lymphocyte proportion, UIP pattern, and fibrosis extent were significantly and independently associated with disease progression in the derivation cohort (n = 240). Binary thresholds for increased BAL lymphocyte proportion and extensive fibrosis were identified as 25% and 20%, respectively. An increased BAL lymphocyte proportion was rare in patients with a UIP pattern (8 of 135; 5.9%) or with extensive fibrosis (7 of 144; 4.9%). In the validation cohort (n = 290), an increased BAL lymphocyte proportion was associated with a significantly lower probability of disease progression in patients with nonextensive fibrosis or a non-UIP pattern. Conclusions: BAL lymphocytosis is rare in patients with extensive fibrosis or a UIP pattern on CT. In patients without a UIP pattern or with limited fibrosis, a BAL lymphocyte proportion of ⩾25% was associated with a lower likelihood of progression.

Advancing pediatric perioperative care in India: A contemporary overview.

BACKGROUND: In the last 30 years, significant advances have been made in pediatric medical care globally. However, there is a persistent urban-rural gap which is more pronounced in low middle-income countries than high-income countries, similar urban-rural gap exists in India. While on one hand, health care is on par or better than healthier nations thriving international medical tourism industry, some rural parts have reduced access to high-quality care. AIM: With this background, we aim to provide an overview of the present and future of healthcare in India. METHODOLOGY: With the cumulative health experience of the authors or more than 100 years, we have provided our experience and expertise about healthcare in India in this narrative educational review. This is supplemented by the government plans and non government plans as appropriate. References are used to justify as applicable. RESULTS: With the high percentage of pediatric population like other low to middle-income countries, India faces challenges in pediatric surgery and anesthesia due to limited resources and paucity of specialized training, especially in rural areas. Data on the access and quality of care is scarce, and the vast rural population and uneven resource distribution add to the challenges along with the shortage of pediatric surgeons in these areas of specialized care . Addressing these challenges requires a multi faceted strategy that targets both immediate and long-term healthcare needs, focusing on improving the facilities and training healthcare professionals. Solutions could include compulsory rural service, district residency programs, increasing postgraduate or residency positions, and safety courses offered by national and international organizations like Safer Anesthesia from Education Pediatrics, Vital Anesthesia Simulation Training, and World Federation of Society of Anesthesiologists pediatric fellowships. CONCLUSION: India has achieved great strides in perioperative health care and safety. It has become the major international medical industry due to high-quality care, access and costs. Crucially, India needs to establish local hubs for pediatric perioperative care training to enhance healthcare delivery for children.

S100 Calcium-Binding Protein A9, a Potential Novel Diagnostic Biomarker for Idiopathic Pulmonary Fibrosis.

BACKGROUND: Neutrophilic inflammation is a characteristic feature of idiopathic pulmonary fibrosis (IPF). S100 calcium-binding protein A9 (S100A9) is a neutrophil-derived protein involved in the development of neutrophil-related chronic inflammatory disorders. However, the role of S100A9 in IPF remains unclear. METHODS: We used enzyme-linked immunosorbent assays to measure S100A9 levels in bronchoalveolar lavage fluid (BALF) and serum obtained from healthy controls (HCs) and patients with IPF, non-specific interstitial pneumonia, hypersensitivity pneumonitis, and sarcoidosis. RESULTS: Compared with HCs, BALF S100A9 levels were significantly higher in IPF patients (P < 0.001), patients with hypersensitivity pneumonitis (P = 0.043), and patients with nonspecific interstitial pneumonia (P < 0.001). The S100A9 level in BALF of 0.093 ng/mL could distinguish IPF patients from HCs, with a specificity of 78.8% and a sensitivity of 81.6%. Similarly, the S100A9 level in BALF of 0.239 ng/mL had a specificity of 64.7% and a sensitivity of 66.7% for distinguishing IPF patients from patients with other interstitial lung diseases. Additionally, BALF S100A9 levels were significantly correlated with neutrophil counts (r = 0.356, P < 0.001) in BALF. IPF patients with S100A9 levels in BALF > 0.533 ng/mL had lower survival rates, compared with patients who had levels ≤ 0.553 ng/mL (n = 49; hazard ratio [HR], 3.62; P = 0.021). Combination analysis revealed that IPF patients with S100A9 levels in BALF> 0.553 ng/mL or neutrophil percentages > 49.1% (n = 43) had significantly lower survival rates than patients with S100A9 levels in BALF ≤ 0.553 ng/mL and neutrophil percentages ≤ 49.1% (n = 41) (HR, 3.91; P = 0.014). Additionally, patients with serum S100A9 levels > 0.077 ng/mL (n = 29) had significantly lower survival rates than patients with levels ≤ 0.077 ng/mL (n = 53, HR, 2.52; P = 0.013). S100A9 was expressed on neutrophils and macrophages in BALF from IPF patients as well as α-smooth muscle actin positive cells in the lung tissues. CONCLUSION: S100A9 is involved in the development and progression of IPF. Moreover, S100A9 levels in BALF and serum may be surrogate markers for IPF diagnosis and survival prediction, particularly when analyzed in combination with neutrophil percentages.

Immunological Landscapes in Lung Transplantation: Insights from T Cell Profiling in BAL and PBMC.

Lung transplant recipients frequently encounter immune-related complications, including chronic lung allograft dysfunction (CLAD). Monitoring immune cells within the lung microenvironment is pivotal for optimizing post-transplant outcomes. This study examined the proportion of T cell subsets in paired bronchoalveolar lavage (BAL) and peripheral PBMC comparing healthy (n = 4) and lung transplantation patients (n = 6, no CLAD and n = 14 CLAD) using 14-color flow cytometry. CD4+ T cell proportions were reduced in CD3 cells in both PBMC and BAL, and positive correlations were discerned between T cell populations in peripheral PBMC and BAL, suggesting the prospect of employing less invasive PBMC sampling as a means of monitoring lung T cells. Furthermore, regulatory T cells (Tregs) were enriched in BAL when compared to peripheral PBMC for transplant recipients. A parallel positive correlation emerged between Treg proportions in BAL and peripheral PBMC, underscoring potential avenues for monitoring lung Tregs. Finally, the most promising biomarker was the Teff (CD8+Granzyme B+)-Treg ratio, which was higher in both the PBMC and BAL of transplant recipients compared to healthy individuals, and increased in the patients with CLAD compared to no CLAD and healthy patients. Conclusions: Distinct T cell profiles in BAL and peripheral PBMC underscore the significance of localized immune monitoring in lung transplantation. The Teff (CD8+granzyme B+)-Treg ratio, particularly within the context of CLAD, emerges as a promising blood and BAL biomarker reflective of inflammation and transplant-related complications. These findings emphasize the imperative need for personalized immune monitoring strategies that tailored to address the unique immunological milieu in post-transplant lungs.

A Novel MIP-1-Expressing Macrophage Subtype in BAL Fluid from Healthy Volunteers.

Tissue availability remains an important limitation of single-cell genomic technologies for investigating cellular heterogeneity in human health and disease. BAL represents a minimally invasive approach to assessing an individual's lung cellular environment for diagnosis and research. However, the lack of high-quality, healthy lung reference data is a major obstacle to using single-cell approaches to study a plethora of lung diseases. Here, we performed single-cell RNA sequencing on over 40,000 cells isolated from the BAL of four healthy volunteers. Of the six cell types or lineages we identified, macrophages were consistently the most numerous across individuals. Our analysis confirmed the expression of marker genes defining cell types despite background signals because of the ambient RNA found in many single-cell studies. We assessed the variability of gene expression across macrophages and defined a distinct subpopulation of cells expressing a set of genes associated with Macrophage Inflammatory Protein 1 (MIP-1). RNA in situ hybridization and reanalysis of published lung single-cell data validated the presence of this macrophage subpopulation. Thus, our study characterizes lung macrophage heterogeneity in healthy individuals and provides a valuable resource for future studies to understand the lung environment in health and disease.

Safety and anti-tumor activity of lisavanbulin administered as 48-hour infusion in patients with ovarian cancer or recurrent glioblastoma: a phase 2a study.

PURPOSE: Lisavanbulin (BAL101553) is the prodrug of avanbulin (BAL27862), a microtubule-destabilizing agent. The goal of this study (NCT02895360) was to characterize the safety, tolerability and antitumor activity of lisavanbulin administered as a 48-hour intravenous (IV) infusion at the recommended Phase 2 dose (RP2D) of 70 mg/m2. Results from the Phase 1 dose-escalation portion of the study identifying the RP2D have been previously reported. Here, we present the findings from the Phase 2a portion of this study. Methods. This multi-center, open-label study included patients with ovarian, fallopian-tube, or primary peritoneal cancer that was either platinum-resistant or refractory (11 patients), or with first recurrence of glioblastoma (12 patients). Lisavanbulin was administered as a 48-hour IV infusion on Days 1, 8, and 15 of a 28-day cycle. Results. Lisavanbulin was well tolerated in both patient cohorts. Thirteen patients (56.5%) developed 49 adverse events assessed as related to study treatment. The majority were mild or moderate; four were grade 3/4. Sixteen SAEs were reported in nine patients (39.1%), with none considered related to study treatment. No AEs led to permanent treatment discontinuation. Three patients in the ovarian cancer cohort had stable disease with lesion size reductions after two cycles of treatment; in the glioblastoma cohort, one patient showed partial response with a > 90% glioblastoma area reduction as best response, and one patient had stable disease after eight cycles of treatment. Conclusion. This study demonstrated a favorable safety and tolerability profile of 48-hour continuous IV infusion of lisavanbulin in patients with solid extracranial tumors or glioblastoma. Clinicaltrials.gov registration: NCT02895360.

Alveolar macrophages from EVALI patients and e-cigarette users: a story of shifting phenotype.

Exposure to e-cigarette vapors alters important biologic processes including phagocytosis, lipid metabolism, and cytokine activity in the airways and alveolar spaces. Little is known about the biologic mechanisms underpinning the conversion to e-cigarette, or vaping, product use-associated lung injury (EVALI) from normal e-cigarette use in otherwise healthy individuals. We compared cell populations and inflammatory immune populations from bronchoalveolar lavage fluid in individuals with EVALI to e-cigarette users without respiratory disease and healthy controls and found that e-cigarette users with EVALI demonstrate a neutrophilic inflammation with alveolar macrophages skewed towards inflammatory (M1) phenotype and cytokine profile. Comparatively, e-cigarette users without EVALI demonstrate lower inflammatory cytokine production and express features associated with a reparative (M2) phenotype. These data indicate macrophage-specific changes are occurring in e-cigarette users who develop EVALI.

Solid-Phase Synthesis of PROTACs and SNIPERs on Backbone Amide Linked (BAL) Resin.

Developing straightforward but flexible approaches to PROTAC synthesis that can incorporate the structural elements of emerging designs can improve the quality and efficiency of PROTAC development. Solid-phase approaches could offer many advantages over conventional PROTAC synthesis if diverse chemistries and topographies can be incorporated. We have exploited the backbone-amide-linked (BAL) resin to employ an array of solid-phase organic reactions, providing access to VHL- and IAP-targeting degraders using the BRD4-targeting JQ1 conjugates as examples.

Performance of galactomannan testing from endotracheal aspirate to guide bronchoalveolar lavage in the diagnosis of invasive aspergillosis.

PURPOSE: Invasive aspergillosis is a major threat to immunocompromised individuals. Galactomannan (GM) is used as a biomarker for invasive aspergillosis. Investigations recommended in current guidelines include GM testing of bronchoalveolar lavage (BAL) fluids. GM testing of endotracheal aspirate, the sampling of which is less invasive, less resource-intensive and less aerosol-generating, is not validated. We compared the performance of endotracheal aspirate GM as a screening tool to predict BAL fluid GM-positivity in patients with suspected invasive aspergillosis. METHODS: Of each patient, a pair of corresponding endotracheal aspirate and BAL fluid samples was tested and compared for GM results. Two sample sets were included. The first consisted of 140 consecutive BAL fluid/endotracheal aspirate pairs obtained from 133 patients. The pairs of the second sample set (n = 38) were selected based on the criterion that the BAL tested positive for GM. All specimens were obtained in a German 2,000 bed tertiary care center. RESULTS: Among BAL fluid GM-positive samples, endotracheal aspirate GM demonstrated poor specificity (72%) but high sensitivity (92% in predicting BAL fluid GM of ≥ 0.50 and 91% for BAL fluid GM of ≥ 1.00) and an excellent negative predictive value (98%). The use of a marginally elevated cutoff of 0.63 resulted in an improved specificity (72-81%), without loss of sensitivity. CONCLUSIONS: For screening purposes, one might consider testing endotracheal aspirate for GM, which could help avoid unnecessary BAL.

Predictive markers related to local and systemic inflammation in severe COVID-19-associated ARDS: a prospective single-center analysis.

BACKGROUND: As the COVID-19 pandemic strains healthcare systems worldwide, finding predictive markers of severe courses remains urgent. Most research so far was limited to selective questions hindering general assumptions for short- and long-term outcome. METHODS: In this prospective single-center biomarker study, 47 blood- and 21 bronchoalveolar lavage (BAL) samples were collected from 47 COVID-19 intensive care unit (ICU) patients upon admission. Expression of inflammatory markers toll-like receptor 3 (TLR3), heme oxygenase-1 (HO-1), interleukin (IL)-6, IL-8, leukocyte counts, procalcitonin (PCT) and carboxyhemoglobin (CO-Hb) was compared to clinical course. Clinical assessment comprised acute local organ damage, acute systemic damage, mortality and outcome after 6 months. RESULTS: PCT correlated with acute systemic damage and was the best predictor for quality of life (QoL) after 6 months (r = - 0.4647, p = 0.0338). Systemic TLR3 negatively correlated with impaired lung function (ECMO/ECLS: r = - 0.3810, p = 0.0107) and neurological short- (RASS mean: r = 0.4474, p = 0.0023) and long-term outcome (mRS after 6 m: r = - 0.3184, p = 0.0352). Systemic IL-8 correlated with impaired lung function (ECMO/ECLS: r = 0.3784, p = 0.0161) and neurological involvement (RASS mean: r = - 0.5132, p = 0.0007). IL-6 in BAL correlated better to the clinical course than systemic IL-6. Using three multivariate regression models, we describe prediction models for local and systemic damage as well as QoL. CO-Hb mean and max were associated with higher mortality. CONCLUSIONS: Our predictive models using the combination of Charlson Comorbidity Index, sex, procalcitonin, systemic TLR3 expression and IL-6 and IL-8 in BAL were able to describe a broad range of clinically relevant outcomes in patients with severe COVID-19-associated ARDS. Using these models might proof useful in risk stratification and predicting disease course in the future. Trial registration The trial was registered with the German Clinical Trials Register (Trial-ID DRKS00021522, registered 22/04/2020).

Extracellular traps are evident in Romanowsky-stained smears of bronchoalveolar lavage from children with non-cystic fibrosis bronchiectasis.

BACKGROUND AND OBJECTIVE: The importance of extracellular traps (ETs) in chronic respiratory conditions is increasingly recognized but their role in paediatric bronchiectasis is poorly understood. The specialized techniques currently required to study ETs preclude routine clinical use. A simple and cost-effective ETs detection method is needed to support diagnostic applications. We aimed to determine whether ETs could be detected using light microscopy-based assessment of Romanowsky-stained bronchoalveolar lavage (BAL) slides from children with bronchiectasis, and whether the ETs cellular origin could be determined. METHODS: Archived Romanowsky-stained BAL slides from a cross-sectional study of children with bronchiectasis were examined for ETs using light microscopy. The cellular origin of individual ETs was determined based on morphology and physical contact with surrounding cell(s). RESULTS: ETs were observed in 78.7% (70/89) of BAL slides with neutrophil (NETs), macrophage (METs), eosinophil (EETs) and lymphocyte (LETs) ETs observed in 32.6%, 51.7%, 4.5% and 9%, respectively. ETs of indeterminate cellular origin were present in 59.6% of slides. Identifiable and indeterminate ETs were co-detected in 43.8% of slides. CONCLUSION: BAL from children with bronchiectasis commonly contains multiple ET types that are detectable using Romanowsky-stained slides. While specialist techniques remain necessary to determining the cellular origin of all ETs, screening of Romanowsky-stained slides presents a cost-effective method that is well-suited to diagnostic settings. Our findings support further research to determine whether ETs can be used to define respiratory endotypes and to understand whether ETs-specific therapies may be required to resolve airway inflammation among children with bronchiectasis.

Autoimmune Pulmonary Alveolar Proteinosis.

Autoimmune pulmonary alveolar proteinosis (PAP) is a rare disease characterized by myeloid cell dysfunction, abnormal pulmonary surfactant accumulation, and innate immune deficiency. It has a prevalence of 7-10 per million; occurs in individuals of all races, geographic regions, sex, and socioeconomic status; and accounts for 90% of all patients with PAP syndrome. The most common presentation is dyspnea of insidious onset with or without cough, production of scant white and frothy sputum, and diffuse radiographic infiltrates in a previously healthy adult, but it can also occur in children as young as 3 years. Digital clubbing, fever, and hemoptysis are not typical, and the latter two indicate that intercurrent infection may be present. Low prevalence and nonspecific clinical, radiological, and laboratory findings commonly lead to misdiagnosis as pneumonia and substantially delay an accurate diagnosis. The clinical course, although variable, usually includes progressive hypoxemic respiratory insufficiency and, in some patients, secondary infections, pulmonary fibrosis, respiratory failure, and death. Two decades of research have raised autoimmune PAP from obscurity to a paradigm of molecular pathogenesis-based diagnostic and therapeutic development. Pathogenesis is driven by GM-CSF (granulocyte/macrophage colony-stimulating factor) autoantibodies, which are present at high concentrations in blood and tissues and form the basis of an accurate, commercially available diagnostic blood test with sensitivity and specificity of 100%. Although whole-lung lavage remains the first-line therapy, inhaled GM-CSF is a promising pharmacotherapeutic approach demonstrated in well-controlled trials to be safe, well tolerated, and efficacious. Research has established GM-CSF as a pulmonary regulatory molecule critical to surfactant homeostasis, alveolar stability, lung function, and host defense.

Bronchoalveolar lavage fluid polymerase chain reaction for invasive pulmonary aspergillosis among high-risk patients: a diagnostic meta-analysis.

BACKGROUND: Polymerase chain reaction (PCR) assays are perceived to facilitate the diagnosis of fungal infections. However, due to lack of standardization, the value of bronchoalveolar lavage (BAL) fluid PCR in diagnosis of invasive pulmonary aspergillosis (IPA) remains unclear. METHODS: We conducted a systematic meta-analysis to evaluate the accuracy of BAL fluid PCR in IPA diagnosis among high-risk patients. All studies involving patients at risk for IPA were included. The sensitivity, specificity, positive and negative likelihood ratios of BAL fluid PCR were summarized for diagnosis of proven/probable IPA, or proven IPA only. Potential heterogeneity was assessed by subgroup analyses and meta-regression. RESULTS: Forty-one studies involving 5668 patients were analyzed. The summary sensitivity, specificity, positive and negative likelihood ratios of BAL fluid PCR for proven/probable IPA were 0.75 (95% CI = 0.67-0.81), 0.94 (95% CI = 0.90-0.96), 11.8 (95% CI = 7.7-18.1) and 0.27 (95% CI = 0.20-0.36), respectively. Whereas for proven IPA only, sensitivity and specificity were 0.91 (95% CI = 0.68-0.98) and 0.80 (95% CI = 0.74-0.85) in fourteen studies involving 2061 patients. Significant heterogeneity was present due to the underlying disease, antifungal treatment and differences in DNA extraction techniques and choice of PCR assay. Compared to patients with hematological malignancies (HM) and hematopoietic stem cell/solid organ transplantation (HSCT/SOT), sensitivity was higher in the population with disease such as chronic obstructive pulmonary disease, solid tumor, autoimmune disease with prolonged use of corticosteroids, etc. (0.88 vs. 0.68, P < 0.001), which was related to the concurrent use of antifungal prophylaxis among patients with HM and HSCT/SOT. CONCLUSION: BAL fluid PCR is a useful diagnostic tool for IPA in immunocompromised patients and is also effective for diagnosing IPA in patients without HM and HSCT/SOT. Furthermore, standard protocols for DNA extraction and PCR assays should be focused on to improve the diagnostic accuracy. Trial registration PROSPERO, registration number CRD42021239028.

Multiple infections in an immunocompromised patient-How cytology can help.

Opportunistic infections in immunocompromised patients can present a diagnostic challenge. This case report describes multiple pulmonary infections-Pneumocystic jirovecii, Histoplasma capsulatum, and cytomegalovirus-in an HIV-positive patient. The morphological findings are described, and the importance of cytology for the rapid diagnosis of these infections is highlighted.

A rare diagnosis of pulmonary actinomycosis by bronchoalveolar lavage cytology.

The role of a bronchoalveolar lavage sample cell block in the diagnosis of pulmonary actinomycosis.

Could the Oxidation of α1-Antitrypsin Prevent the Binding of Human Neutrophil Elastase in COVID-19 Patients?

Human neutrophil elastase (HNE) is involved in SARS-CoV-2 virulence and plays a pivotal role in lung infection of patients infected by COVID-19. In healthy individuals, HNE activity is balanced by α1-antitrypsin (AAT). This is a 52 kDa glycoprotein, mainly produced and secreted by hepatocytes, that specifically inhibits HNE by blocking its activity through the formation of a stable complex (HNE-AAT) in which the two proteins are covalently bound. The lack of this complex, together with the detection of HNE activity in BALf/plasma samples of COVID-19 patients, leads us to hypothesize that potential functional deficiencies should necessarily be attributed to possible structural modifications of AAT. These could greatly diminish its ability to inhibit neutrophil elastase, thus reducing lung protection. The aim of this work was to explore the oxidation state of AAT in BALf/plasma samples from these patients so as to understand whether the deficient inhibitory activity of AAT was somehow related to possible conformational changes caused by the presence of abnormally oxidized residues.