Haemophilia, AIDS and lung epithelial permeability

Lung 99mTc DTPA transfer was measured in HIV antibody-positive haemophiliacs (11 smokers, 26 nonsmokers, 5 patients with Pneumocystis carinii pneumonia (PCP]. Lung 99mTc DTPA transfer as a marker of lung epithelial permeability was measured as the half time of transfer (from airspace into blood). This half time was faster in smokers compared to nonsmokers and the transfer curve was monoexponential. In nonsmokers no difference was observed between asymptomatic HIV-positive haemophiliacs and normal subjects, with the exception of the lung bases. At the lung bases in HIV-positive haemophiliac nonsmokers the transfer was faster than in normal individuals, implying increased alveolar permeability. Pneumocystis carinii pneumonia resulted in a rapid transfer of 99mTc DTPA (mean T50 of 2 minutes) and the transfer curve was biphasic, confirming previous observations in homosexual HIV antibody-positive patients with PCP. These changes returned to a monoexponential profile by 6 weeks following successful treatment. The DTPA lung transfer study may enable clinicians to instigate therapy for PCP without the need for initial bronchoscopy and provide a noninvasive method for the reassessment of patients should further respiratory signs or symptoms develop. This method is considered to be highly cost-effective in that it obviates the use of factor VIII concentrates required to cover bronchoscopic procedures and, with its early application and ease of use as a follow-up investigation, permits the evaluation of patients on an outpatient basis, thus reducing hospital costs.     

Increased risk of Pneumocystis carinii and community-acquired pneumonia with tobacco use in HIV disease.

OBJECTIVES: Tobacco smoking-related diseases continue to be of great health concern for the public, in general, and may be particularly deleterious for immunosuppressed HIV-positive individuals, who exhibit widespread tobacco use. METHODS: A total of 521 HIV-infected subjects consecutively admitted to Jackson Memorial Hospital between 2001-2002 were enrolled in the study. Research data included a medical history, details of tobacco and illicit drug use and complete computerized hospital information. Blood was drawn to obtain T lymphocyte profiles and viral load levels. Statistical analysis methods included Pearson, Student's t- and Chi-square tests and SAS Proc CATMOD. RESULTS: Tobacco use was prevalent, with 65% of the 521 HIV-positive hospitalized patients being current smokers. Overall, current tobacco users reported smoking an average of 15+/-13 cigarettes per day for an average of 15+/-14 years, with 40% smoking more than one pack per day. Pulmonary infections accounted for 49% of the total hospital admissions: 52% bacterial pneumonias, 24% Pneumocystis carinii pneumonia (PCP), 12% non-tuberculous mycobacterial diseases (NTM), 11% tuberculosis and 1% bronchitis. Many of the respiratory patients (46%) had been on highly active antiretroviral therapy (HAART) for over six months and 42% had received PCP and/or NTM prophylaxis. After matching the cases by HAART and CDC stage, the hazardous risk of being hospitalized with a respiratory infection was significantly higher for smokers than non-smokers (95% CI 1.33-2.83; p=0.003). Respiratory infections were noted in (37%) of the HAART-treated patients, and most (67%) occurred in smokers. CATMOD analyses controlling for HAART, viral load and CD4, indicated that HIV-infected smokers were three times more likely to be hospitalized with PCP and twice as likely to be hospitalized with community-acquired pneumonia than non-smokers, with increased risk related to the number of cigarettes/day in a dose-dependent manner. CONCLUSIONS: Tobacco use, which is widespread among HIV-infected subjects, increases the risk of pulmonary diseases, particularly PCP and CAP, two respiratory infections with high prevalence and morbidity risks even in the era of HAART.     

HIV-associated opportunistic pneumonias

Among the HIV-associated pulmonary complications, opportunistic pneumonias are major causes of morbidity and mortality. The spectrum of HIV-associated opportunistic pneumonias is broad and includes bacterial, mycobacterial, fungal, viral and parasitic pneumonias. Bacterial pneumonia is the most frequent opportunistic pneumonia in the United States and Western Europe while tuberculosis is the dominant pathogen in sub-Saharan Africa. With the use of combination antiretroviral therapy and prophylaxis, the incidence of Pneumocystis pneumonia (PCP) has declined. Nevertheless, PCP continues to occur in persons who are unaware of their HIV infection, those who fail to access medical care, and those who fail to adhere to antiretroviral therapy or prophylaxis. Although pneumonias due to Cryptococcus neoformans , Histoplasma capsulatum , Coccidioides immitis , cytomegalovirus and Toxoplasma gondii are less frequent, their presence in the lung is often indicative of disseminated disease and is associated with significant mortality.     

The incidence of legionella pneumonia: A 1-year prospective study in a large community hospital

In a 1-year prospective study, 28 of 476 pneumonia patients (5.9%) were diagnosed as having legionella pneumonia. Legionella pneumonia was diagnosed in 12 (5%) of 240 community-acquired pneumonias and in 16 (6.8%) of 236 nosocomial pneumonias. Four methods of establishing diagnosis were used: serum antibody detection, direct proof of legionellae by immunofluorescence, culture, and legionella antigen detection in urine. The latter method proved to be clearly advantageous to all other methods in establishing the diagnosis. Twelve of the 28 patients (42.8%) died; all of them had severe underlying diseases. The fatality rate in patients treated with erythromycin was 18.8% (3/16 cases) and 75% (9/12 cases) in patients treated with antibiotics other than erythromycin. In 57.1% (16/28 patients) legionella pneumonia was acquired nosocomially. The results of our study underscore the need to use a broad spectrum of legionella diagnostic methods routinely and to administer antibiotics effective against legionellae in cases of pneumonia of unknown cause.     

A comparison of 99mTc-DTPA and 113mIn-DTPA aerosol clearances in humans. Effects of smoking, hyperinflation, and in vitro oxidation

As an index of permeability of the alveolar epithelium, the clearance of an inhaled aerosol of 99mTc-DTPA is increased in several disease states. However, the usefulness of the test to assess the severity of disease is limited because healthy smokers also have abnormally rapid rates of clearance. Because the stability of the 99mTc-DTPA bond might be a contributory factor, we tested the affinity of 99mTc for DTPA in vitro, and in groups of healthy smokers (n = 13) and nonsmokers (n = 7) we measured the clearances of 99mTc-DTPA and 113mIn-DTPA, which have a similar molecular shape and charge. In vitro, sodium hypochlorite or hydrogen peroxide released as much as 98% of free 99mTc from the 99mTc-DTPA complex. When incubated with human neutrophils stimulated with phorbol myristate acetate, between 4 and 7% of free 99mTc-DTPA was released after 30 min, and 12% was released after 60 min. In vivo, the clearances of both 99mTc-DTPA and 113mIn-DTPA in the smokers (n = 13) were faster than in the nonsmokers (n = 7) (p less than 0.05). Within the smokers, the mean 99mTc-DTPA clearance (T1/2 25 +/- 4 min) was faster than the mean 113mIn-DTPA clearance (34 +/- 6 min), (p less than 0.05). For nonsmokers, the difference was smaller (T1/2 99mTc-DTPA, 56 +/- 6; T1/2 113mIn-DTPA, 62 +/- 6) and not significant. During hyperinflation, smokers (n = 8) and nonsmokers (n = 8) both demonstrated an increase in 113mIn-DTPA clearance.(ABSTRACT TRUNCATED AT 250 WORDS)     

Increased lung permeability following long-term use of free-base cocaine (crack)

The clearance of inhaled 99mTc DTPA aerosol from the lungs is used as an index of lung epithelial permeability. Using the radioaerosol method, we investigated the effects of long-term "crack" (free-base cocaine) inhalation on lung permeability in 23 subjects. Eighteen control subjects (12 nonsmokers and 6 cigarette smokers) with no history of drug use were also studied. Subjects inhaled approximately 150 muCi (approximately 5.6 MBq) of 99mTc DTPA aerosol and quantitative gamma camera images of the lungs were acquired at 1-min increments for 25 minutes. Regions of interest (ROIs) were selected to include the following: (1) both lungs; (2) each individual lung; and (3) the upper, middle, and lower thirds of each lung. 99mTc DTPA lung clearance was determined from the slopes of the respective time-activity plots for the different RIOs. Radioaerosol clearance half-times (T1/2) for the seven nonsmoking crack users (61.5 +/- 18.3 minutes) were longer than for the seven cigarette-smoking crack users (27.9 +/- 16.9 minutes) and nine cigarette-smoking crack plus marijuana users (33.5 +/- 21.6 minutes). T1/2 for the nonsmoking crack users was significantly shorter (p less than 0.001) than for the nonsmoking control group (123.8 +/- 28.7 minutes). T1/2 for the cigarette-smoking drug users was similar to that of the cigarette-smoking control group (33.1 +/- 17.8 minutes), suggesting a similar mechanism of damage from the smoke of crack and tobacco. From these groups, one nonsmoker and 11 cigarette smokers displayed biexponential 99mTc DTPA clearances, indicative of greater lung injury than found in the usual cases of monoexponential clearance. The upper lungs of all crack users groups cleared faster than the lower lungs. The faster and biexponential clearance properties of inhaled 99mTc DTPA aerosol were the principal functional abnormalities found in all the drug users. In contrast, 19 of 23 crack users had normal spirometry and gas exchange. These results indicate that 99mTc DTPA may provide a sensitive and useful assay to evaluate the physiologic effects of cocaine inhalation in the lung.     

Synchronous roentgenographically occult lung carcinoma in patients with resectable primary lung cancer

OBJECTIVE: To assess the prevalence of synchronous roentgenographically occult lung carcinoma (ROLC) in patients with resectable roentgenographically visible lung cancer (RVLC). METHODS: Patients undergoing surgery for RVLC in the same University Hospital were prospectively evaluated before surgery by fluorescence bronchoscopy under local anesthesia to detect synchronous ROLC. All abnormal areas, with the exception of the RVLC, had biopsies made. RESULTS: From June 1996 to January 1999, 43 patients (male/female ratio: 1.7/1.0) were evaluated before lobectomy (n = 34) or pneumonectomy (n = 10) for 44 primary RVLC. There were 10 T1N0, 19 T2N0, 1 T1N1, 9 T2N1, 1 T3N0, 3 T1N2, and 1 T3N1 lesions. The histologic type was mainly squamous carcinoma (n = 21) and adenocarcinoma (n = 14). All but two patients were smokers or ex-smokers (mean +/- SD, 48 +/- 28 pack-years). A total of 177 endobronchial biopsies were performed (4.1 +/- 2.5); 8 were too small to be informative, 43 showed non-preneoplastic alterations, and 50 were normal. There were 7 basal cell hyperplasias, 56 metaplasias, 9 dysplasias, and 4 carcinomas in situ (CIS). All the dysplasias and CIS lesions were observed in eight subjects. The synchronous CIS were treated by surgery (n = 1) or localized therapeutic modalities (n = 3). CONCLUSIONS: The high prevalence of synchronous early lung cancers (9.3%) as well as metaplasia and dysplasia in this series of patients with resectable RVLC suggests that fluorescence bronchoscopy may be a useful adjunct in the preoperative evaluation of lung cancer.     

Detection of HIV-1 in human lung macrophages using the polymerase chain reaction

We have used the polymerase chain reaction to investigate HIV-1 infection of lung macrophages from 44 AIDS patients with pneumonia. Proviral HIV-1 DNA was detected in the lung macrophages of 47% (21 of 44) of patients tested; 32% (seven of 21) of the patients had Pneumocystis carinii pneumonia (PCP), and 56% (11 of 21) had pneumonia caused by other aetiological agents. Matched peripheral blood specimens were obtained from 22 patients in this study, and HIV-1-specific DNA was detected in 100% (22 out of 22) of non-adherent white cell preparations tested. HIV was detected in blood monocytes of 11 out of 22 patients (50%), and a virus signal was also found in the lung macrophages of eight of these patients. Our results indicate that PCP does not predispose lung macrophages to HIV-1, nor does HIV-1 infection of lung macrophages increase the probability of contracting PCP.     

Value of technetium-99m diethyltriamine pentaaceticacid radioaerosol inhalation lung scintigraphy for the stage of amiodarone-induced pulmonary toxicity

BACKGROUND: Amiodarone is a potent antiarrhythmic agent that is limited in clinical use by its adverse effects, including potentially life threatening amiodarone-induced pulmonary toxicity (AIPT). The alteration of technetium-99m diethyltriaminepentaaceticacid (Tc-99m DTPA) radioaerosol lung clearance in AIPT was experimentally investigated. METHODS: Eighteen white New Zealand rabbits (initial weight 4.1+/-0.2 kg) were divided into two groups. AIPT group (n=13) was administered amiodarone (20 mg/kg BW) ip as a 5% aqueous solution for 6 week. The controls (n=5) were administered the same amount of 0.9% saline ip. Four rabbits of AIPT group died due to AIPT. The reminders of AIPT group (n=9) and controls underwent Tc-99m DTPA radioaerosol lung scintigraphy at the end of the treatment period. AIPT group was divided into two subgroups according to histopathologic evaluation. AIPT-I had interstitial pneumonitis (n=4) and AIPT-II had interstitial pneumonitis with fibrosis (n=5). RESULTS: The mean T(1/2) values of in control, AIPT-I, and AIPT-II groups were found 54+/-4.4, 39.2+/-11.7 and 114.6+/-16.7 min, respectively. The mean T(1/2) values of Tc-99m DTPA significantly differ than other groups (X(2)=11.78, P=0.02). The significantly increased T(1/2) values was noted in AIPT-II group when compared with control (P=0.001). In contrast, AIPT-I group has significantly lower T(1/2) values than control group (P=0.03). CONCLUSION: We suggested that Tc-99m DTPA radioaerosol inhalation lung scintigraphy provides an accurate evaluation about stage of lung toxicity and therefore may be a useful tool for the monitoring of AIPT.     

Non-invasive management of fever and breathlessness in HIV positive patients

In a prospective study of 72 human immunodeficiency virus (HIV) positive patients presenting with fever and breathlessness, a non-invasive management protocol, incorporating a scanning technique using radioactively labelled diethylenetriamine penta acetate (DTPA) and sputum induction, was found to be highly sensitive and specific in the early detection of Pneumocystis carinii pneumonia (PCP). At presentation, the DTPA scan was abnormal in 34 of 36 cases of PCP, irrespective of smoking history, whilst the chest radiograph was diffusely abnormal in 21 cases. Sputum induction identified 7 of 14 patients with PCP in the first six months of its use and 7 of 10 patients over the last six months. The DTPA lung scan and induced sputum examination are non-invasive techniques which can be used to investigate out-patients. In combination they detected all cases of PCP at presentation, reduced the need for bronchoscopy, resulted in a low case fatality (5.4%) and reduced the need for admission.     

Influence of Pneumocystis carinii pneumonia on serum and tissue concentrations of pentamidine administered to rats by tracheal injections.

Pentamidine isethionate was administered by the tracheal route to control rats and immunodepressed rats with Pneumocystis carinii pneumonia (PCP). The serum concentration of pentamidine base 20 min after the administration was higher in the PCP rats (309 +/- 165 ng/ml) than in the control animals (71 +/- 36 mg/ml; p less than 0.001); 90 min after the injection the proportion of the pentamidine administered was lower in the right lung of the PCP rats (29 +/- 15%) than in the control rats (57 +/- 23%; p = 0.038); the proportion of pentamidine in the left kidney was higher in the PCP rats (14 +/- 4%) than in the control animals (4 +/- 2%; p less than 0.001). Respiratory clearance of 99mTc-DTPA, an index of the permeability of the respiratory epithelium, was higher in the PCP rats (1.84 +/- 0.42 %/min) than in the controls (0.44 +/- 0.11 %/min; p less than 0.001). We conclude that the more rapid diffusion of pentamidine from the alveolar lumen to the pulmonary circulation is explained by the increased alveolocapillary permeability as a result of pneumocystosis.     

Kinetics of lung clearance of 99mTc-DTPA in smoking patients with sarcoidosis compared to healthy smokers

Investigation of lung clearance of 99mTc-labelled diethylene triamine penta-acetic acid (DTPA) in smoking sarcoid patients has been impeded by difficulties to differ between pathology of clearance kinetics caused by sarcoidosis and by smoking. This study explores the kinetics of lung clearance of 99mTc-DTPA in 15 current smokers with intrathoracic sarcoidosis. The results are compared with findings from 16 healthy smokers. Measurements of lung clearance over 180 min, i.e. longer than usual, revealed in II of the sarcoid patients a bi-exponential lung clearance course, which is pathologic. All healthy smokers also showed a bi-exponential lung clearance. In the analysis of the bi-exponential curve an initial fast, and a slow clearance component could be separated. The smokers with sarcoidosis had a significantly higher elimination rate of the slow component than the healthy smokers. Thus, analysis of the late part of the lung clearance curve may be rewarding in smoking sarcoid patients. The study shows that lung clearance of 99mTc-DTPA may be a method useful also in smoking patients with sarcoidosis.     

A step test to assess exercise-related oxygen desaturation in interstitial lung disease.

A 6-min step test (6MST) may constitute a practical method for routinely assessing effort tolerance and exercise-related oxyhaemoglobin desaturation (ERD) in the primary care of patients with interstitial lung disease. In total, 31 patients (19 males) with idiopathic pulmonary fibrosis (n = 25) and chronic hypersensitivity pneumonia were submitted, on different days, to two 6MSTs. Physiological responses were compared with those found on maximal and submaximal cycle ergometer tests at the same oxygen uptake (V'(O(2))). Chronic breathlessness was also determined, as measured by the baseline dyspnoea index (BDI). Responses to 6MST were highly reproducible: 1.3+/-2.0 steps x min(-1), +/-5 beats x min(-1) (cardiac frequency), +/-50 mL x min(-1) (V'(O(2))), +/-7 L x min(-1) (minute ventilation) and +/-2% (arterial oxygen saturation measured by pulse oximetry (S(p,O(2)))). The number of steps climbed in 6 min was correlated to peak V'(O(2)) and the BDI. There were significant associations among the tests in relation to presence (change in S(p,O(2)) between rest and exercise > or = 4%) and severity (S(p,O(2)) <88%) of ERD. Four patients, however, presented ERD only in response to 6MST. Resting diffusing capacity of the lung for carbon monoxide and alveolar-arterial oxygen tension difference were the independent predictors of the number of steps climbed. A single-stage, self-paced 6-min step test provided reliable and reproducible estimates of exercise capacity and exercise-related oxyhaemoglobin desaturation in interstitial lung disease patients.     

Fibrinogen depletion and control of permeability in oleic acid lung injury

To determine if the biphasic pulmonary clearance of aerosolized 99mTc diethylene penta acetate (99mTc-DTPA) observed in oleic acid lung injury represents acute epithelial damage followed by sealing as a result of intra-alveolar fibrin deposition, we examined the effect of fibrinogen depletion. 99mTc-DTPA clearance was assessed in three groups of rabbits: Group 1, normal fibrinogen + oleic acid injury; Group 2, fibrinogen-depleted + oleic acid injury; Group 3, fibrinogen-depleted with no oleic acid injury. In Group 3 animals with no lung injury, the 99mTc-DTPA clearance rate, expressed as k, the percent decrease in thoracic radioactivity, was similar to that previously reported for healthy rabbits (k = 1.16 +/- 0.57%/min, mean +/- SD). Oleic acid administration to Groups 1 and 2 resulted in significantly faster clearance rates, with identical biphasic curves in all animals, irrespective of fibrinogen status. There were no significant differences between either the initial fast phase (k, Group 1 = 5.26 +/- 1.83%/min, Group 2 = 5.70 +/- 1.77%/min) or the subsequent slow phase (k, Group 1 = 1.67 +/- 0.63%/min, Group 2 = 1.57 +/- 0.55%/min, p greater than 0.05). On histologic examination, Groups 1 and 2 showed greater cellular interstitial infiltrate, alveolar edema, and hemorrhage than did Group 3. Fibrinogen depletion plus oleic acid injury resulted in greater alveolar cellular exudate, edema, and hemorrhage than did either oleic acid or fibrinogen depletion alone. We conclude that fibrinogen is not necessary to produce biphasic 99mTc-DTPA clearance in oleic acid lung injury.     

Triggering receptor expressed on myeloid cells: role in the diagnosis of lung infections.

The triggering receptor expressed on myeloid cells (TREM)-1 is a recently described molecule, which plays an important role in myeloid cell-activated inflammatory responses. TREM-1 is expressed on blood neutrophils and monocytes, and also on alveolar macrophages, thus suggesting a potential role in lung inflammatory responses against infections. To investigate the differential expression of TREM-1 in lung infections, its levels were assessed in bronchoalveolar lavage specimens from patients with community-acquired pneumonia or tuberculosis. TREM-1 was also investigated in patients with interstitial lung diseases, as a model of noninfectious inflammatory disease of the lung. TREM-1 expression was significantly increased in lung neutrophils and in lung macrophages of patients with pneumonia (n=7; 387.9+/-61.4 and 660.5+/-18.3, respectively) compared with patients with pulmonary tuberculosis (n=7; 59.2+/-13.1 and 80.6+/-291.2) and patients with interstitial lung diseases (n=10; 91.8+/-23.3 and 123.9+/-22.8). In contrast, TREM-1 expression on peripheral blood neutrophils was no different among the three groups. In conclusion, these data suggest that triggering receptor expressed on myeloid cells-1 is selectively expressed in the lungs of patients with pneumonia caused by extracellular bacteria and not in patients with tuberculosis, providing a potential marker for differential diagnosis.     

Community-acquired Legionnaires' disease

Legionellae are ubiquitous aquatic organisms. They are unique among the agents commonly responsible for bacterial pneumonia in humans in that they are not part of the normal human flora but are acquired from environmental sources. Prospective studies have shown that legionellae consistently rank among the top three bacteria as etiologic agents of community-acquired pneumonia. The clinical presentation of Legionnaires' disease is not distinguishable from that of other bacterial pneumonias. Culture of respiratory secretions using selective media, combined with one or more rapid diagnostic methods (direct fluorescent antibody staining, radiolabelled DNA probe, or urinary antigen detection) provides a specific diagnosis in the vast majority of cases. Sporadic cases have been linked to legionella colonization of water systems in homes and the work setting. Antibiotics commonly used in the therapy of community-acquired pneumonias, such as beta-lactam agents, are ineffective. Specific therapy with erythromycin reduces mortality to less than 10%.     

Pulmonary function in human immunodeficiency virus infection. A prospective 18-month study of serial lung function in 474 patients.

To investigate the development of a reduced DLCO in patients with HIV-related disease, we studied 474 HIV-seropositive patients and performed serial lung function measurements over 18 months. The mean values of DLCO at presentation were lower in patients with more advanced HIV disease compared with asymptomatic HIV-seropositive patients (DLCO 88% of predicted). When compared with the DLCO in asymptomatic HIV-seropositive patients, the DLCO had reduced values in patients with persistent generalized lymphadenopathy (PGL) (82% of predicted, p less than 0.05), acquired deficiency syndrome-related complex (ARC) (73% predicted, p less than 0.001), nonpulmonary Kaposi's sarcoma (KS) (72% of predicted, p less than 0.001), nonpulmonary complications of AIDS excluding KS (73% of predicted, p less than 0.001), pulmonary KS (63% of predicted, p less than 0.001), pulmonary mycobacterial infection (68% of predicted, p less than 0.05), pyogenic infection (70%, p less than 0.05), acute Pneumocystis carinii pneumonia (PCP; 49%, p less than 0.001), and following recovery from PCP (71%, p less than 0.001). Serial lung function measurements over 18 months revealed no change in DLCO within any patient group, and in particular there was no tendency for a gradual decline. Clinical deterioration due to the development of PCP was associated with a reduction in DLCO. Conversely, in patients recovering from PCP, there was a partial improvement in DLCO over 3 months. Zidovudine (AZT) use did not affect DLCO within any diagnostic group or the recovery in DLCO following PCP. However, cigarette smoking was associated with further reductions in DLCO in all patient groups and with an impaired recovery of DLCO following acute PCP.(ABSTRACT TRUNCATED AT 250 WORDS)     

Serum lactate dehydrogenase activity in patients with AIDS and Pneumocystis carinii pneumonia. An adjunct to diagnosis

We investigated whether serum lactate dehydrogenase activity (LD) is significantly elevated in patients with acquired immunodeficiency syndrome (AIDS) and Pneumocystis carinii pneumonia (PCP) when compared to patients with non-Pneumocystis pneumonia. We measured LD (U/L), blood total lymphocyte count (1,000/cu mm), and alveolar-arterial oxygen tension difference P(A-a)O2 (mm Hg), in 30 patients with AIDS and PCP (group 1), four patients with AIDS or AIDS-related complex (ARC) and non-Pneumocystis pneumonia (NPCP) (group 2), and seven patients with pneumococcal pneumonia and bacteremia (PPB) (group 3). In patients with AIDS and PCP, LD was 509 +/- 35 (mean +/- SE), which was significantly elevated in comparison to both AIDS/ARC patients with NPCP (228 +/- 21) (p less than .001), and patients with PPB (211 +/- 21) (p less than .001). There was a significant positive correlation between LD and P(A-a)O2 (r = .51, p = 0.01). P(A-a)O2 was markedly elevated in both AIDS patients with PCP (48 +/- 3), and patients with pneumococcal pneumonia (44 +/- 3), but only moderately elevated in AIDS/ARC patients with NPCP (29 +/- 6). These results suggest that measurement of LD may be useful in differentiating Pneumocystis pneumonia from non-Pneumocystis pneumonia. In addition, the increase in LD correlates with the degree of pulmonary oxygen transfer abnormality.     

Presentation of Pneumocystis carinii pneumonia as unilateral hyperlucent lung

Pneumocystis carinii pneumonia (PCP) presented as unilateral hyperlucent lung in a 27-month-old patient with a brain tumor who was receiving chemotherapy. Although unilateral pneumonia is an uncommon presentation of PCP in non-AIDS patients, PCP must be suspected in any pediatric cancer patient not receiving trimethoprim-sulfamethoxazole prophylaxis and receiving intensive chemotherapy.     

Concurrent bacterial lung infection in patients with AIDS, PCP, and respiratory failure.

STUDY OBJECTIVES: To determine and compare the incidence of concurrent bacterial lung infection in intubated and nonintubated patients with the acquired immunodeficiency syndrome (AIDS) and Pneumocystis carinii pneumonia (PCP) requiring medical intensive care unit (MICU) admission for support of their respiratory function. DESIGN: Retrospective review of medical records. SETTING: A large university hospital and AIDS treatment center. PATIENTS: All AIDS/PCP patients admitted to the MICU for support of oxygenation and/or ventilation between 1985 and 1989. Survival was defined as discharge from the hospital; nonsurvival was defined as death any time during the hospitalization. Patients with acute spinal cord injury (SCI) were used as controls to determine the incidence of nosocomial pneumonia in ICU patients of similar age without AIDS. MEASUREMENTS AND RESULTS: Twenty-nine AIDS/PCP patients met study criteria; eight (28 percent) were survivors and 21 (72 percent) were nonsurvivors. There was no significant difference in duration of intubation or duration of ICU stay between survivors and nonsurvivors with or without intubation. The incidence of bacterial concurrent lung infection (CLI) in AIDS/PCP patients overall was 7 percent and in intubated AIDS/PCP patients it was 10 percent. There was no statistically significant difference in the incidence of bacterial CLI between the survivors and nonsurvivors or between intubated and nonintubated patients with AIDS/PCP. The incidence of nosocomial pneumonia in SCI overall was 17 percent and in intubated SCI patients it was 30 percent. CONCLUSIONS: The incidence of bacterial lung infections in our retrospective study of AIDS patients with PCP is remarkably less than in the general ICU population with respiratory failure and in our control patients with SCI, although the differences did not attain statistical significance. This finding may be related to antimicrobial therapy directed against P carinii. Endotracheal intubation in patients with AIDS and PCP, who were undergoing appropriate antimicrobial therapy, did not result in a significantly higher incidence of bacterial lung infections than in those who were not intubated. There was no significant difference in the incidence of bacterial lung infections between those AIDS/PCP patients who survived episodes of severe respiratory failure and those who did not. Endotracheal intubation should not be delayed or withheld from this patient population due to concerns of pulmonary bacterial superinfection.