Pneumocystis carinii pneumonia: a comparison between patients with the acquired immunodeficiency syndrome and patients with other immunodeficiencies

Management of infectious and immunological complications of acquired immunodeficiency syndrome (AIDS). Current and future prospects

AIDS is caused by a newly recognised virus (human immunodeficiency virus; HIV) which induces a profound defect in cellular immune function associated with increased susceptibility to opportunistic infections and certain malignancies. The clinical presentation of HIV ranges from asymptomatic infection to severe immunodeficiency manifesting as severe life-threatening infectious diseases or malignancies. While major research efforts are being directed toward development of vaccine and discovery of effective antiretroviral drugs, clinicians are faced with AIDS patients with multiple and complicated medical problems including opportunistic infections and certain malignancies. Currently, efforts are directed toward early diagnosis, treatment, and prevention of recurrence of these opportunistic infections. The current approaches are reviewed in this article. Major recent developments in AIDS research include the isolation of the HIV on culture and the availability of the antibody test. Aside from vaccine and antiretroviral drugs, other measures that may be of benefit in the treatment of AIDS patients are immunological enhancement and reconstitution. Several studies are underway to evaluate antiviral agents in the treatment of HIV infection. Those undergoing clinical trial include suramin, ribavirin, antimoniotungstate, phosphonoformate and azidothymidine. Immune enhancers that have been used include alpha- and gamma-interferon and interleukin-2. HLA-matched lymphocyte transfusions and bone marrow transplantations have been used alone and in combination to replace the AIDS patient's defective immune system.

Pneumocystis carinii pneumonia. Review of 53 cases

Between 1976 and 1983, 53 cases of Pneumocystis carinii pneumonia were documented at the Mayo Clinic. Underlying diseases included leukemia in 15 patients, lymphoma in nine, nonhematologic malignancies in five, acquired immune deficiency syndrome in two, an various inflammatory diseases treated by corticosteroids in 16 patients. Cytotoxic drugs with corticosteroids were used in 68 percent of patients, whereas 23 percent received corticosteroids alone. Clinical features consisted of progressive dyspnea (74 percent), cough (55 percent), and fever (62 percent), with normal findings on examination (43 percent), or crackles (53 percent). Arterial oxygen tension and oxygen saturation were 48.6 +/- 12.8 mm Hg and 81.2 +/- 6.5 percent, respectively. Chest roentgenographs exhibited diffuse alveolar and interstitial infiltrates with predominantly perihilar distribution. The diagnostic rates for open lung biopsy and bronchoscopy were 97 percent and 62 percent, respectively. Clinical improvement and survival following appropriate therapy were noted in 22 patients (41.5 percent), whereas the remaining 31 patients died within four weeks of hospitalization. When survivors were compared with nonsurvivors, there was no difference in mean age, leukocyte counts, arterial oxygen tension, or duration of symptoms before treatment. A coexisting pulmonary infection was identified more frequently in nonsurvivors (51.6 percent) than in survivors (22.7 percent, p = 0.01). The mortality from P. carinii pneumonia alone was 47 percent, whereas 76 percent of those with coexisting infection died. Despite antibiotic therapy and potentially effective chemoprophylaxis, P. carinii pneumonia remains a significant and life-threatening complication of diseases or treatments associated with immune suppression.

Pulmonary nocardiosis in the acquired immunodeficiency syndrome. Diagnosis with bronchoalveolar lavage and treatment with non-sulphur containing drugs

A patient with the acquired immunodeficiency syndrome (AIDS) presented with Pneumocystis carinii pneumonia and pulmonary nocardiosis. The nocardial lesions appeared small and localized on chest radiograph. On two separate occasions, nocardial organisms were absent in transbronchial lung biopsy specimens, but were identified in bronchoalveolar lavage fluid probably because the latter specimen sampled a larger area of lung. The patient was initially treated with trimethoprim-sulfamethoxazole (TMP/SMX) for both infections. When TMP/SMX was discontinued because of an adverse reaction, the nocardiosis promptly exacerbated but was then easily controlled with minocycline and amikacin followed by minocycline and cycloserine. Among patients with AIDS who have sulfamethoxazole hypersensitivity during treatment for nocardiosis, alternative drugs may be efficacious and may be particularly important in this setting because they have a lower incidence of toxicity.

The clinical challenges of AIDS and HIV infection

Researchers trying to resolve the questions surrounding the AIDS epidemic may feel like Hercules trying to slay the Hydra: for every head that is cut off, two new ones grow in its place. Doctors have never treated their patients in a social vacuum, but the expectations and anxieties engendered by AIDS are bringing fundamental changes in clinical p-actice. Drugs are being raced from the laboratory bench to the bedside, health care providers are being forced to recognize new types of family constellations, and the general public is being shocked into awareness of the importance of prudent infection control policies. Clinical practitioners have had to deal with the ethical consequences of routine and arcane decisions as never before, knowing that yesterday's experiment or hospital rounds can become tomorrow's lead feature in the news media.

Management of infectious complications in acquired immunodeficiency syndrome

Infectious complications are the most common cause of death in patients with acquired immunodeficiency syndrome (AIDS). Opportunistic infections associated with defects in both T and B lymphocyte function have been observed. Invasive infections, including those secondary to procedures both in and out of the hospital, must also be considered. Reliance on serologic antibody tests is ill-advised since antibody response is often not effective. Since simultaneous infections frequently develop in patients with AIDS, attempts to identify pathogens by culture and histopathology should be aggressive and thorough. With rapid diagnosis and therapy, many of the infections will respond. Prolonged treatment is indicated as recrudescence is common.

Prospective evaluation of a monoclonal antibody in diagnosis of Pneumocystis carinii pneumonia

To evaluate the ability of a mouse monoclonal antibody, 2G2, directed against human Pneumocystis carinii, to detect the organism in clinical specimens, a prospective study of the antibody in an indirect immunofluorescent assay was undertaken. P carinii was rapidly detected in thirteen of fourteen bronchoalveolar lavage specimens positive by toluidine-blue-O stain, none of eleven lavage specimens negative by toluidine-blue-O, neither of two impression smears of histologically negative open-lung biopsy specimens, and both of two impression smears of histologically positive necropsy specimens. Immunofluorescence with monoclonal antibody 2G2 is a rapid, simple, and specific technique for detection of P carinii in clinical specimens.

Bronchoalveolar lavage as the exclusive diagnostic modality for Pneumocystis carinii pneumonia. A prospective study among patients with acquired immunodeficiency syndrome

Pneumocystis carinii pneumonia (PCP) is the most common life-threatening opportunistic infection among patients with the acquired immunodeficiency syndrome (AIDS). Because retrospective studies suggested that bronchoalveolar lavage (BAL) compared favorably to lung biopsy in the diagnosis of PCP, we prospectively evaluated the utility of BAL in 40 consecutive patients with AIDS or risk of AIDS who presented with respiratory complaints. The BAL revealed P carinii in 36 of 42 episodes of pneumonia (86 percent) among 40 patients. Clinical follow-up of the six patients whose BAL was negative for PCP suggested only one possible false negative BAL for PCP. Therefore, BAL detected PCP in 36 of 37 patients for a sensitivity of 97 percent. BAL detected cytomegalovirus in 15 of 38 patients, as well as Mycobacterium avium-intracellulare and Cryptococcus (each in one patient). By virtue of accuracy and lack of morbidity demonstrated in our study, BAL should supplant lung biopsy techniques in the evaluation of AIDS patients with pulmonary symptoms.

Overwhelming pneumonia

Overwhelming pneumonia may be caused by a large number of different organisms in both immunocompetent and compromised hosts. In this article, the most common etiologies of overwhelming pneumonia are considered from an epidemiologic and clinical point of view.

Diagnosis for interstitial lung disease in patients with acquired immunodeficiency syndrome (AIDS): a prospective comparison of bronchial washing, alveolar lavage, transbronchial lung biopsy, and open-lung biopsy

This study was undertaken to compare prospectively the diagnostic yield of the various bronchoscopic techniques with that of open-lung biopsy for interstitial lung disease in patients with acquired immunodeficiency syndrome (AIDS). Under general anesthesia, 15 patients sequentially underwent bronchial washing, transbronchial lung biopsy, alveolar lavage, and open-lung biopsy in the same segment of lung. Of nine patients with Pneumocystis carinii, seven were diagnosed by means of the transbronchial lung biopsy, eight by the open-lung biopsy, and all nine by alveolar lavage. Of the six patients with cytomegalovirus, five were diagnosed by the open-lung biopsy, five by the transbronchial lung biopsy, and three by alveolar lavage. The sensitivities of the procedures for identifying infection were washings (15%), transbronchial lung biopsy (50%), alveolar lavage (73%), and open-lung biopsy (88%). Combined, transbronchial lung biopsy and alveolar lavage showed a diagnostic yield (85%) for infections comparable to that of open-lung biopsy (88%), thereby obviating the need for open-lung biopsy for such diagnoses. However, open-lung biopsy was the only procedure that diagnosed Kaposi's sarcoma in lung.

Bedside bronchoalveolar lavage for the diagnosis of Pneumocystis carinii pneumonia in patients with the acquired immunodeficiency syndrome

We studied the utility of bronchoalveolar lavage (BAL) as the primary diagnostic procedure in 46 separate episodes of suspected Pneumocystis carinii pneumonia (PCP) in 42 patients with AIDS. 35 procedures were performed at the bedside. A separate group of 40 historical controls with AIDS and suspected PCP had transbronchial biopsy (TBB) as the primary procedure. At least 100 cc of saline in 50 cc aliquots was used for BAL. Specimens were processed using rapid silver methenamine, Papanicolau, and Ziehl Neelson stains with appropriate cultures. There were 29 positives and 17 true negatives for PCP with BAL, confirmed by biopsy in 11, and using clinical criteria in 6. Accuracy, sensitivity, and predictive value of a negative result were all 100%. There was no significant difference in yield between TBB and BAL (p greater than 0.10). BAL was useful to diagnose other opportunistic organisms including CMV, atypical mycobacteria, and fungi. The frequency of isolates in the TBB group were comparable. TBB was complicated by 4 episodes of major bleeding. The data indicate that bedside BAL is effective, and safer than TBB in patients with AIDS and suspected PCP. We advocate BAL as the primary diagnostic procedure which can be performed at the bedside in patients with suspected PCP and AIDS. The high accuracy and predictive value of a negative BAL for PCP suggests confirmatory procedures may not be necessary in many cases.

Acquired immunodeficiency syndrome

The acquired immunodeficiency syndrome (AIDS) was recognized as a distinct clinical entity in 1981 and was characterized by unexplained opportunistic infections and an aggressive form of Kaposi's sarcoma. High risk groups for contracting AIDS include homosexual men, parenteral drug users, hemophiliacs, recipients of blood and blood products, and heterosexual contacts of such individuals. Immunologic abnormalities associated with AIDS include lymphopenia, functional T-cell deficits, B-lymphocyte defects, and various serologic abnormalities. The causative virus has been identified as the human T-lymphotropic virus/lymphadenopathy associated virus (HTLV-III/LAV). AIDS represents the severe end of the clinical spectrum of infection with HTLV-III/LAV. Other manifestations are asymptomatic carriage, generalized lymphadenopathy, and a set of non-specific symptoms, termed the AIDS-related-complex (ARC). Although seen predominantly in the United States, AIDS has a world-wide occurrence. No known therapy for AIDS exists. Research efforts are being directed at antiviral therapy, immunorestoration and the development of a vaccine.

Pneumocystis carinii in human lungs at autopsy

To get some information about the prevalence of Pneumocystis carinii in the Danish population we have examined autopsy lung biopsies from patients at 2 large hospitals in Copenhagen, Righospitalet (RH) and Finseninstituttet (F), in a 5-year period from 1979 to 1984. Imprints made from the biopsies were stained with the toluidine blue O method and examined microscopically for pneumocysts. A total of 1762 patients were examined and pneumocysts found in 83 (4.7%); at RH 54 (4.9%) of 1106 patients and at F29 (4.4%) of 656 patients. A possible influence of certain climatic factors on the prevalence of pneumocysts in humans was shown: low temperature, low vapour pressure and low relative humidity seem to be correlated with low prevalence of pneumocysts. The general use of trimethoprim-sulfamethoxazole in the hospitals may possibly influence the prevalence of pneumocysts: the amount requested in the period of the investigation is negatively correlated with the prevalence of pneumocysts.

Techniques for examining Pneumocystis carinii in fresh specimens

Pneumocystis carinii was examined in fresh preparations of infected rat lung homogenates and tissue culture supernatants by a variety of light microscope techniques, vital dyes, and histologic stains. Phase-contrast microscopy, Nomarski interference-contrast microscopy, and bright-field microscopy with oblique illumination provided excellent views of P. carinii. Erythrosin B, and to a lesser extent trypan blue, were helpful in assessing organism viability. The use of Triton X-100-Giemsa stain permitted differentiation of the developmental stages in the P. carinii life cycle. The techniques developed here are easily adaptable to the microbiology laboratory and thus should have important clinical and research applications.

Method of testing the susceptibility of Pneumocystis carinii to antimicrobial agents in vitro

Rat Pneumocystis carinii grown on lung-derived cell lines in tissue culture flasks and multiwell plates was tested for susceptibility to four antimicrobial agents currently being used in the treatment of human pneumocystosis. Standard criteria for organism quantitation, replication, viability, and inoculum size were established. Trimethoprim-sulfamethoxazole inhibited P. carinii growth at a concentration ratio of 1:19 microgram/ml, and pentamidine isethionate was active at 0.1 microgram/ml. alpha-Difluoromethylornithine, an inhibitor of polyamine biosynthesis, inhibited P. carinii at a concentration of 1 mM once erythrocytes (which are high in polyamine content) were removed from the inoculum; this effect could be overcome by the polyamine putrescine. Dapsone suppressed P. carinii replication at a dose of 0.1 microgram/ml, but this effect was lost after 72 h in culture. Overall, the reduction in P. carinii numbers with these drugs was relatively modest (45 to 84%), which is consistent with their lack of lethal effects on the organism in vivo. Thus, the system presented here should be helpful in developing new anti-P. carinii agents and in elucidating their mechanism of action.

Pulmonary disease in the immunocompromised host (2)

In this second segment of our article on pulmonary disease in the immunocompromised host (ICH), we review the infections associated with pulmonary infiltrates in the ICH and the diagnostic approaches for both infectious and noninfectious conditions. Although certain immunologic defects may predispose patients to specific infectious agents, virtually any infectious agent can cause pulmonary disease in any ICH. Physical findings and laboratory observations may give the clinician clues about probable causes of infection. Nevertheless, invasive diagnostic procedures-in particular, open-lung biopsy-are often necessary to diagnose pulmonary disease in the ICH. The relatively new technique of bronchoalveolar lavage is useful in diagnosing pulmonary disease in the patients with acquired immunodeficiency syndrome (AIDS). Further studies are necessary to confirm the reliability of this procedure as a diagnostic method in the ICH who does not have AIDS.

Pulmonary complications of the acquired immunodeficiency syndrome: a clinicopathologic study of 70 cases

The pulmonary complications of 70 patients with the acquired immunodeficiency syndrome (AIDS) are reviewed. Pneumocystis carinii pneumonia (PCP), present in 67 per cent of the patients, was diagnosed by fiberoptic bronchoscopy with transbronchial biopsies in all of the patients except two adults, who required open lung biopsy, and two children, in whom the infection was detected only at autopsy. Other opportunistic infections, such as cytomegalovirus pneumonitis, mycobacterial infections, invasive candidiasis, toxoplasmosis, cryptococcosis, and histoplasmosis, were more difficult to diagnose by fiberoptic bronchoscopy. In only four cases were these conditions detected during life. Neoplasms and lymphoproliferative processes also presented diagnostic problems, and only one case each of Kaposi's sarcoma and lymphoid interstitial pneumonitis were detected by fiberoptic bronchoscopy. In four other cases these conditions, as well as two pulmonary lymphomas, diffuse large cell immunoblastic type, were detected only at autopsy. Sixty-eight per cent of the patients in this study died, usually with progressive intractable respiratory failure and pulmonary complications that had not been diagnosed during life, including potentially treatable diseases, such as bacterial pneumonias, PCP, nontuberculous mycobacteria, invasive candidiasis, toxoplasmosis, and invasive aspergillosis. The need for earlier detection of pulmonary complications in patients with AIDS is discussed.