Limper, Andrew H.

Introduction.Pneumocystispneumonia (PCP) is rising in the non-HIV population and associates with higher morbidity and mortality. The aggressive immunosuppressive regimens, as well as the lack of stablished guidelines for chemoprophylaxis, are likely contributors to this increased incidence. Herein, we have explored the underlying conditions, immunosuppressive therapies, and clinical outcomes of PCP in HIV-negative patients.Methods. Retrospective analysis of PCP in HIV-negative patients at Mayo Clinic from 2006–2010. The underlying condition, immunosuppressive therapies, coinfection, and clinical course were determined. PCP diagnosis required symptoms of pneumonia and identification of the organisms by visualization or by a real-time polymerase chain reaction.Results. A total of 128 cases of PCP were identified during the study period. Hematological malignancies were the predisposing condition for 50% of the patients. While 87% had received corticosteroids or other immunosuppressive therapies for >4 weeks prior to the diagnosis, only 7 were receiving PCP prophylaxis. Up to 43% of patients were not on daily steroids. Sixty-seven patients needed Intensive Care Unit (ICU) and 53 received mechanical ventilation. The mortality for those patients requiring ICU was 40%.Conclusions. PCP diagnosis in the HIV-negative population requires a high level of suspicion even if patients are not receiving daily corticosteroids. Mortality remains high despite adequate treatment.

Abstract N-acetylglucosamine (GlcNAc) serves as an essential structural sugar on the cell surface of organisms. For example, GlcNAc is a major component of bacterial peptidoglycan, it is an important building block of fungal cell walls, including a major constituent of chitin and mannoproteins, and it is also required for extracellular matrix generation by animal cells. Herein, we provide evidence for a uridine diphospho (UDP)–GlcNAc pathway in Pneumocystis species. Using an in silico search of the Pneumocystis jirovecii and P. murina (Pm) genomic databases, we determined the presence of at least four proteins implicated in the Saccharomyces cerevisiae UDP-GlcNAc biosynthetic pathway. These genes, termed GFA1, GNA1, AGM1, and UDP-GlcNAc pyrophosphorylase (UAP1), were either confirmed to be present in the Pneumocystis genomes by PCR, or, in the case of Pm uap1 (Pmuap1), functionally confirmed by direct enzymatic activity assay. Expression analysis using quantitative PCR of Pneumocystis pneumonia in mice demonstrated abundant expression of the Pm uap1 transcript. A GlcNAc-binding recombinant protein and a novel GlcNAc-binding immune detection method both verified the presence of GlcNAc in P. carinii (Pc) lysates. Studies of Pc cell wall fractions using high-performance gas chromatography/mass spectrometry documented the presence of GlcNAc glycosyl residues. Pc was shown to synthesize GlcNAc in vitro. The competitive UDP-GlcNAc substrate synthetic inhibitor, nikkomycin Z, suppressed incorporation of GlcNAc by Pc preparations. Finally, treatment of rats with Pneumocystis pneumonia using nikkomycin Z significantly reduced organism burdens. Taken together, these data support an important role for GlcNAc generation in the cell surface of Pneumocystis organisms.

Recent literature has demonstrated concern over the risk of Pneumocystis jirovecii pneumonia (PJP) when administering rituximab with combination chemotherapy such as in R‐CHOP; however, the exact risk and potential need for prophylaxis is unknown. We sought to determine the incidence of PJP infection following R‐CHOP administration in patients with B‐cell lymphoma. Consecutive patients diagnosed with B‐cell lymphoma receiving R‐CHOP were evaluated from chemotherapy initiation until 180 days after the last administration. The primary outcome was cumulative incidence of PJP infection. Secondary endpoints included the association of rituximab, prednisone and subsequent chemotherapy with PJP infection risk. A total of 689 patients (53% male, median age 66 years) were included. Seventy‐three percent of patients completed at least 6 cycles of R‐CHOP treatment. Median rituximab and prednisone cumulative doses were 3950 mg and 5325 mg, respectively. Median daily prednisone dose through end of treatment was 45 mg (range 7.6 mg to 119 mg). The cumulative incidence of PJP was 1.51% (95% CI 0.57–2.43, at maximum follow‐up of 330 days), below 3.5%, the conventional threshold for prophylaxis. Univariate analysis did not detect a statistically significant association between PJP and rituximab, steroids, or receipt of additional chemotherapy in this patient population. Our results demonstrate a low occurrence of Pneumocystis pneumonia during R‐CHOP treatment of B‐cell lymphoma and argue against universal anti‐Pneumocystis prophylaxis in this setting. Further investigations should focus on targeted anti‐Pneumocystis prophylaxis for patients presenting with high‐risk baseline characteristics or when receiving rituximab‐inclusive intensive combination chemotherapy regimens as treatment for other aggressive lymphoma subtypes. Am. J. Hematol. 91:1113–1117, 2016. © 2016 Wiley Periodicals, Inc.

ABSTRACT TGF‐β plays a central role in the pathogenesis of fibroproliferative disorders. Defining the exact underlying molecular basis is therefore critical for the development of viable therapeutic strategies. Here, we show that expression of the facilitative glucose transporter 1 (GLUT1) is induced by TGF‐β in fibroblast lines and primary cells and is required for the profibrotic effects of TGF‐β. In addition, enhanced GLUT1 expression is observed in fibrotic areas of lungs of both patients with idiopathic pulmonary fibrosis and mice that are subjected to a fibrosis‐inducing bleomycin treatment. By using pharmacologic and genetic approaches, we demonstrate that up‐regulation of GLUT1 occurs via the canonical Smad2/3 pathway and requires autocrine activation of the receptor tyrosine kinases, platelet‐derived and epidermal growth factor receptors. Engagement of the common downstream effector PI3K subsequently triggers activation of the MEK and mammalian target of rapamycin complex 2, which cooperate in regulating GLUT1 expression. Of note, inhibition of GLUT1 activity and/or expression is shown to impair TGFβ–driven fibrogenic processes, including cell proliferation and production of profibrotic mediators. These findings provide new perspectives on the interrelation of metabolism and profibrotic TGF‐β signaling and present opportunities for potential therapeutic intervention.—Andrianifahanana, M., Hernandez, D. M., Yin, X., Kang, J.‐H., Jung, M.‐Y., Wang, Y., Yi, E. S., Roden, A. C., Limper, A. H., Leof, E. B. Profibrotic up‐regulation of glucose transporter 1 by TGF‐β involves activation of MEK and mammalian target of rapamycin complex 2 pathways. FASEB J. 30, 3733–3744 (2016) www.fasebj.org

Abstract Rationale Despite shared environmental exposures, idiopathic pulmonary fibrosis (IPF) and chronic obstructive pulmonary disease are usually studied in isolation, and the presence of shared molecular mechanisms is unknown. Objectives We applied an integrative genomic approach to identify convergent transcriptomic pathways in emphysema and IPF. Methods We defined the transcriptional repertoire of chronic obstructive pulmonary disease, IPF, or normal histology lungs using RNA-seq (n = 87). Measurements and Main Results Genes increased in both emphysema and IPF relative to control were enriched for the p53/hypoxia pathway, a finding confirmed in an independent cohort using both gene expression arrays and the nCounter Analysis System (n = 193). Immunohistochemistry confirmed overexpression of HIF1A, MDM2, and NFKBIB members of this pathway in tissues from patients with emphysema or IPF. Using reads aligned across splice junctions, we determined that alternative splicing of p53/hypoxia pathway–associated molecules NUMB and PDGFA occurred more frequently in IPF or emphysema compared with control and validated these findings by quantitative polymerase chain reaction and the nCounter Analysis System on an independent sample set (n = 193). Finally, by integrating parallel microRNA and mRNA-Seq data on the same samples, we identified MIR96 as a key novel regulatory hub in the p53/hypoxia gene-expression network and confirmed that modulation of MIR96 in vitro recapitulates the disease-associated gene-expression network. Conclusions Our results suggest convergent transcriptional regulatory hubs in diseases as varied phenotypically as chronic obstructive pulmonary disease and IPF and suggest that these hubs may represent shared key responses of the lung to environmental stresses.

SummaryPneumocystis jiroveci pneumonia is an opportunistic infection associated with substantial rates of mortality in immunosuppressed patients. Prophylaxis recommendations are mostly targeted toward patients with non‐dermatologic diagnoses. This study was conducted to determine when dermatology patients treated with immunosuppressive medications should be offered P. jiroveci pneumonia prophylaxis. We searched the literature from January 1, 1993, to December 31, 2013, using terms relating to P. jiroveci pneumonia and dermatologic diagnoses to analyze the clinical characteristics of previously affected patients. Guidelines for P. jiroveci pneumonia prophylaxis from other medical fields were also analyzed. Of 17 dermatology patients reported to have contracted P. jiroveci pneumonia, eight (47.1%) died of the pneumonia. Risk factors included lack of prophylaxis, systemic corticosteroid therapy, lymphopenia, hypoalbuminemia, low serum CD4 counts, comorbid pulmonary or renal disease, malignancy, and prior organ transplantation. The present conclusions are limited by heterogeneity among the selected studies and limitations in their identification and selection. However, P. jiroveci pneumonia in dermatology patients is associated with a high mortality rate. Based on our analysis, we propose that prophylaxis be considered in dermatology patients in whom treatment with systemic corticosteroids at doses exceeding 20 mg/day or treatment with corticosteroid‐sparing immunosuppressive agents is anticipated for at least 4 weeks, and in patients with additional risk factors for P. jiroveci pneumonia.

Diffuse pulmonary lymphangiomatosis (DPL) is a rare disease characterized by infiltration of the lung, pleura and mediastinum with thin-walled lymphangiomas. DPL can result in mass effect from infiltrative disease, restrictive and obstructive pulmonary physiology, chylous effusions and respiratory failure. The present article discusses clinical, radiographic and pathological features, and treatment options for DPL.