Gregg Y. Lipschik

Improved diagnosis of Pneumocystis carinii infection by polymerase chain reaction on induced sputum and blood.

Detection of Pneumocystis carinii by the polymerase chain reaction (PCR) may facilitate non-invasive diagnosis of P carinii pneumonia and study of its epidemiology. We have compared the sensitivity and specificity of two PCR methods with those of conventional staining for detection of P carinii in induced sputum, bronchoalveolar lavage fluid (BAL), and blood. Of 71 sputum samples, 17 were from patients with microbiologically confirmed P carinii pneumonia. A nested PCR method correctly identified the presence of P carinii in all 17 (100% sensitive, 95% confidence interval [CI] 81-100%) and found no organisms in 50 of 54 microbiologically negative samples (93% specific, 95% CI 82-98%). PCR with a single primer pair was 71% sensitive (44-90%) and 94% specific (85-99%). The sensitivity of conventional staining methods (direct and indirect fluorescence antibody and toluidine-blue-O tests) was significantly less (38-53%) than that of nested PCR (p less than 0.05). In BAL, neither PCR method was significantly better than the conventional staining methods. P carinii was detected in BAL or sputum from 10 immunocompromised patients without microbiological evidence of P carinii pneumonia, which suggests that symptom-free carriers or subclinical infection can exist. P carinii was detected by nested PCR in blood from 2 of 3 patients with disseminated pneumocystosis but in only 1 of 11 patients with P carinii infection restricted to the lungs. Nested PCR on induced sputum is more sensitive than conventional staining methods for the diagnosis of P carinii pneumonia and provides a non-invasive method of detecting disseminated disease.

Atypical pathologic manifestations of Pneumocystis carinii pneumonia in the acquired immune deficiency syndrome : review of 123 lung biopsies from 76 patients with emphasis on cysts, vascular invasion, vasculitis, and granulomas

The frequency of atypical pathologic manifestations of Pneumocystis carinii pneumonia (PCP) were studied in 123 lung biopsy specimens from 76 National Institutes of Health patients with the acquired immune deficiency syndrome. The following atypical features were observed: interstitial (63%) and intraluminal (36%) fibrosis, absence of alveolar exudate (19%), numerous alveolar macro-phages (9%), granulomatous inflammation (5%), hyaline membranes (4%), marked interstitial pneumonitis (3%), parenchymal cavities (2%), interstitial microcalcification (2%), minimal histologic reaction (2%), and vascular invasion with vasculitis (1%). These atypical features are discussed with emphasis on the significance of cavities, vascular invasion, vasculitis, and granulomas. Immuno-histochemical staining with monoclonal antibodies to the 2G2 and 6B8 antigens of P carinii in paraffin-embedded lung biopsy specimens did not indicate any diagnostic advantage over routine methenamine silver stains. This study provides an important reminder that a wide variety of pathologic manifestations may occur in PCP in human immunodeficiency virus-infected patients and that atypical features should be sought in lung biopsies from patients at risk for PCP.

Purification and characterization of a major human Pneumocystis carinii surface antigen.

Previous studies of Pneumocystis carinii have identified the major surface antigen of rat and human isolates as proteins of 116,000 and 95,000 mol wt, respectively, that are antigenically not identical. In this study both rat and human P. carinii proteins were purified by solubilization with zymolyase followed by molecular sieve and ion exchange chromatography. The native proteins had an apparent mol wt of 290,000 or greater, based on molecular sieve studies as well as cross-linking studies. Both proteins were glycoproteins; treatment with endoglycosidase H resulted in a 9% decrease in mol wt. The carbohydrate composition of the rat P. carinii glycoprotein was distinct from the human isolate; glucose, mannose, galactose, and glucosamine occurred in approximately equimolar ratios in the human P. carinii protein, whereas glucose and mannose were the predominant sugars of the rat P. carinii protein. To evaluate humoral immune responses to the human P. carinii protein, an enzyme-linked immunosorbent assay using purified protein was developed. Some, but not all, patients who subsequently developed P. carinii pneumonia demonstrated a serum antibody response to the surface antigen. Nearly all subjects without a history of P. carinii pneumonia had no detectable antibodies. Purified P. carinii proteins will greatly facilitate the investigation of host-P. carinii interactions.

Interleukin-8 and eicosanoid production in the lung during moderate to severe Pneumocystis carinii pneumonia in AIDS: a role of interleukin-8 in the pathogenesis of P. carinii pneumonia

Pneumocystis carinii pneumonia (PCP) may cause severe respiratory distress. This is believed to be partly caused by the accumulation of neutrophils in the lung. Interleukin-8 (IL-8) and leukotriene B4 (LTB4) are potent neutrophil chemo-attractants and activators. Eicosanoids [i.e. prostaglandins (PG) and leukotrienes (LT)] are pro-inflammatory mediators released from arachidonic acid by action of phospholipase A2 (PLA2) and have been implicated in the host response to micro-organisms. Bronchoalveolar lavage (BAL) was performed on patients with PCP as part of a randomized study of adjuvant corticosteroids vs. placebo, in addition to standard antimicrobial therapy. Re-bronchoscopy was offered at day 10. BAL fluid was available for 26 patients who had follow-up bronchoscopy performed. At diagnosis, IL-8 levels were elevated in patients with PCP, compared to healthy controls, and correlated with relative BAL neutrophilia and P(A-a)O2. LTB4 was also elevated in PCP, but failed to correlate with either BAL neutrophilia or P(A-a)O2. PLA2 activity in patients correlated with IL-8 levels and BAL neutrophilia, but not with P(A-a)O2. A trend towards a decrease in IL-8 levels in BAL fluid was detected in the corticosteroid-treated patients from days 0-10, whereas no change was detected in the placebo group. No change in levels of LTB4, LTC4, PGE2, PGF2a and PLA2 were detected cover time in either treatment group. This study establishes a correlation between IL-8, BAL neutrophilia and P(A-a)O2, and suggests a role of IL-8 as a mediator in the pathogenesis of PCP, whereas the role of eicosanoids seems less clear.

Pneumocystis carinii Glycoprotein A Inhibits Surfactant Phospholipid Secretion by Rat Alveolar Type II Cells

Pneumocystis carinii pneumonia (PCP) remains a major cause of morbidity in AIDS. The pathogenesis of PCP is poorly understood, but evidence of surfactant abnormalities is mounting. The role of the major surface glycoprotein of P. carinii, gpA, in producing surfactant abnormalities was investigated. Rat type II pneumocytes were incubated with [3H]choline, purified gpA, and modulators. Lipid was extracted, and [3H]dipalmitoyl phosphatidylcholine (DPPC) secretion was calculated. Contaminating endotoxin had no effect on DPPC secretion. gpA inhibited basal and ATP-stimulated DPPC secretion in a dose- and time-dependent manner. An anti-gpA monoclonal antibody attenuated inhibition of DPPC secretion. Unglycosylated recombinant gpA inhibited secretion, suggesting that functional activity resides in the protein moiety of gpA. These results suggest that gpA is a specific trigger for abnormalities of surfactant lipids in PCP. This is a unique role for a microbial product in disease pathogenesis and a potentially exploitable therapeutic target.

Blood and Body Fluid Exposures Among US Medical Students in Botswana

IntroductionMedical students from resource-rich countries who rotate in resource-limited settings have little pre-departure experience performing procedures, and lack familiarity with local equipment. The risk of blood and body fluid exposures during such rotations is significant.Aim1) Determine whether a simulation-based intervention reduced exposures among US medical students on a rotation in Botswana; 2) determine whether exposures were underreported; 3) describe exposures and provision of human immunodeficiency virus (HIV) post-exposure prophylaxis (PEP).SettingUniversity of Pennsylvania medical students who traveled to Botswana for a clinical rotation from July 2007 to February 2010 were eligible to participate.Program DescriptionTwenty-two students participated in the simulation-based intervention.Program EvaluationTo evaluate the intervention, we used a pre/post quasi-experimental design and administered a retrospective survey. The response rate was 81.7% (67/82). Needlesticks were eliminated [8/48 (16.7%) to 0/19 (0.0%), p = 0.07]. Splashes were unchanged (6/48 [12.5%) to 3/19 (15.8%), p=>0.99]. Three students did not report their exposure. Fifteen exposures were reported to an attending, who counseled the student regarding HIV PEP. Three students did not take PEP because the exposure was low-risk.DiscussionOur intervention was associated with a decrease in needlestick exposures. Medical schools should consider training to reduce exposures abroad.

Medical Students in Developing Countries

To the Editor:–We appreciate Dr. Cooke’s thoughtful comments about our study of blood and body fluid exposures among US medical students in Botswana. We are sensitive to the perils of “medical tourism,” and have designed our program to avoid it. Our medical students are members of medical teams under the supervision of local physicians. In turn, Penn specialists who live and work full time in Botswana are assigned to supervise the ward work of interns and residents hired by the Ministry of Health and the University of Botswana School of Medicine. Dr. Cooke expressed concern regarding the availability of protective eye gear to Penn trainees but not local doctors. When a local provider performs a procedure, our students offer them their goggles. In most cases, the offer is declined. Importantly, we think it is unwise for a visiting institution like Penn to impose its safety standards on the host institution. However, we think it is critical that Penn provides the level of safety it deems appropriate for its trainees. We believe it is the decision of the governing body, in this case the Ministry of Health, to make recommendations concerning protection of the health care work force in Botswana. Concerning the issue of post-exposure prophylaxis, the Botswana Ministry of Health provides HIV post-exposure prophylaxis to health care workers. In our partnership with the Government of Botswana, we view our role as working with our fellow health care providers to identify and prioritize issues of concern, and to support them as they try to make changes that they think are appropriate locally.

Google Glass Video Capture of Cardiopulmonary Resuscitation Events: A Pilot Simulation Study

Background Video recording of resuscitation from fixed camera locations has been used to assess adherence to guidelines and provide feedback on performance. However, inpatient cardiac arrests often happen in unpredictable locations and crowded rooms, making video recording of these events problematic. Objective We sought to understand the feasibility of Google Glass (GG) as a method for recording inpatient cardiac arrests and capturing salient resuscitation factors for post-event review. Methods This observational study involved recording simulated cardiac arrest events on inpatient medical wards. Each simulation was reviewed by 3 methods: in-room physician direct observation, stationary video camera (SVC), and GG. Nurse and physician specialists analyzed the videos for global visibility and audibility, as well as recording quality of predefined resuscitation events and behaviors. Resident code leaders were surveyed regarding attitudes toward GG use in the clinical emergency setting. Results Of 11 simulated cardiac arrest events, 9 were successfully recorded by all observation methods (1 GG failure, 1 SVC failure). GG was judged slightly better than SVC recording for average global visualization (3.95 versus 3.15, P = .0003) and average global audibility (4.77 versus 4.42, P = .002). Of the GG videos, 19% had limitations in overall interpretability compared with 35% of SVC recordings (P = .039). All 10 survey respondents agreed that GG was easy to use; however, 2 found it distracting and 3 were uncomfortable with future use during actual resuscitations. Conclusions GG is a feasible and acceptable method for capturing simulated resuscitation events in the inpatient setting.

A case of “patchy” pneumonia

Somnath Ghosh, MD Scott Akers, MD Anuj Mittal, MD Debra Adrian, MSN, CRNP Gregg Lipschik, MD Michael Grippi, MD 1 Pulmonary and Critical Care, Health Science Center, University of Texas, Houston, Texas. 2 Radiology Department, Philadelphia VA Medical Center, Philadelphia, Pennsylvania. 3 Internal Medicine, St. Joseph Mercy Oakland, Pontiac, Michigan. Medical Intensive Care Unit (MICU), Philadelphia VA Medical Center, Philadelphia, Pennsylvania. 5 Pulmonary and Critical Care, Philadelphia VA Medical Center, Philadelphia, Pennsylvania. Medicine, University of Pennsylvania Medical Center, Philadelphia, Pennsylvania.

Chemotherapeutic Targets in Pneumocystis carinii

P. carinii pneumonia, the most common life-threatening infection in patients with the acquired immunodeficiency syndrome (AIDS) as well as the most common index diagnosis in AIDS, is caused by an enigmatic pathogen whose metabolism and basic biology are poorly understood (11,12,16). Prior to AIDS, P. carinii pneumonia was largely a rare disease of immunosuppressed children, with a yearly incidence of fewer than 100 cases in the early 1970s (96). The AIDS epidemic has made P. carinii pneumonia an enormously important public health problem; it has become among the most frequent causes of pneumonia requiring hospitalization and is probably the most common cause of death in AIDS. A recent estimate predicts 150,000 cases of P. carinii pneumonia in the next 3–4 years (35). Approximately 80% of patients with AIDS will have at least one episode of P. carinii pneumonia (67). The incidence of P. carinii pneumonia in patients with cancer may also be rising (32), further highlighting the need for improved diagnosis, therapy, and prophylaxis of this once-obscure illness.