Granulomatous pulmonary lesions in patients with the acquired immunodeficiency syndrome (AIDS) and Pneumocystis carinii infection

Hypercalcemia associated with Pneumocystis jirovecii pneumonia in renal transplant recipients: case report and literature review

Background: Pneumocystis jirovecii associated pneumonia is a potentially life-threatening opportunistic infection, occurring most frequently in the first year after renal transplantation, and may be associated with hypercalcemia. Clinical presentation:We report the case of a renal transplant recipient presenting with Pneumocystis jirovecii associated pneumonia and hypercalcemia due to ectopic production of 1,25-dihydroxyvitamin D, 6 years after renal transplantation. Calcemia and 1-25 hydroxyvitamin D levels normalized after our patient was treated by trimethoprim-sulfamethoxazole. Discussion: We review similar cases to delineate the clinical and biological profile of patients with Pneumocystis jirovecii pneumonia associated hypercalcemia. Conclusion:Physicians should evoke this diagnosis in renal transplant recipients presenting with pulmonary infection associated with hypercalcemia.

Unmasking Granulomatous Pneumocystis jirovecii Pneumonia with Nodular Opacity in an HIV-Infected Patient after Initiation of Antiretroviral Therapy

Pneumocystis jirovecii pneumonia (PJP) in patients with HIV infection can, in rare cases, present with pulmonary nodules that histologically involve granulomatous inflammation. This report describes an intriguing case of granulomatous PJP with pulmonary nodules after commencing antiretroviral therapy (ART) in an HIV-infected patient without respiratory signs or symptoms. Diagnosis of granulomatous PJP was only achieved through thoracoscopic lung biopsy. This case suggests that granulomatous PJP should be considered in the differential diagnosis of pulmonary nodules in HIV-infected patients for unmasking immune reconstitution inflammatory syndrome manifestation after initiation of ART.

Pneumocystis jiroveci Pneumonia

Pneumocystis pneumonia (PCP) is one of the most common pulmonary infections in persons with impaired cell-mediated immunity, and particularly those infected with human immunodeficiency virus (HIV).1–7 Pneumocystis was first described in the lungs of guinea pigs, during experiments on American trypanosomiasis by Carlos Chagas8 in 1909 and by Antonio Carinii9 in 1910. Both considered the cysts of Pneumocystis as part of the trypanosome’s life cycle. Shortly afterward the Delanoes10 found identical forms in the lungs of rats that had not been infected with trypanosomes and recognized the organism as a separate species. The name Pneumocystis carinii, was given to this organism as a generic name (Greek:pneumon, “lung”; kystis, “cyst”), honoring Carinii.11

Granulomatous Pneumocystis carinii pneumonia complicating hematopoietic cell transplantation

Pneumocystis carinii pneunonia (PCP) is associated with a wide spectrum of clinical and histopathological presentations. While granulomatous PCP uncommonly occurs in AIDS patients, it is extremely rare in other non-AIDS immunocompromised patients. We identified three patients who developed granulomatous PCP after bone marrow or blood stem cell transplantation. In all cases, fiberoptic bronchoscopy with bronchoalveolar lavage was non-diagnostic, and an open lung biopsy was required for diagnosis. All patients were successfully treated with trimethoprim-sulfamethoxazole. The histological appearance varied from an ill-defined granulomatous pneumonia to well-formed necrotizing granulomas. The typical intraalveolar eosinophilic frothy exudate was absent. Often sparsely distributed, the organisms were detected by GMS and immunohistochemical stains for P. carinii. No other pathogens were identified by additional histochemical stains or by microbiological cultures. Awareness of this unusual granulomatous tissue response to P. carinii and initiation of specific treatment can lead to successful resolution of this potentially lethal infection.

Calcium deposition with or without bone formation in the lung

Pulmonary calcification and ossification occurs with a number of systemic and pulmonary conditions. Specific symptoms are often lacking, but calcification may be a marker of disease severity and its chronicity. Pathophysiologic states predisposing to pulmonary calcification and ossification include hypercalcemia, a local alkaline environment, and previous lung injury. Factors such as enhanced alkaline phosphatase activity, active angiogenesis, and mitogenic effects of growth factors may also contribute. The clinical classification of pulmonary calcification includes both metastatic calcification, in which calcium deposits in previously normal lung or dystrophic calcification, which occurs in previously injured lung. Pulmonary ossification can be idiopathic or can result from a variety of underlying pulmonary, cardiac, or extracardiopulmonary disorders. The diagnosis of pulmonary calcification and ossification requires various imaging techniques, including chest radiography, computed tomographic scanning, and bone scintigraphy. Interpretation of the presence of and the specific pattern of calcification or ossification may obviate the need for invasive biopsy. In this review, specific conditions causing pulmonary calcification or ossification that may impact diagnostic and treatment decisions are highlighted. These include metastatic calcification caused by chronic renal failure and orthotopic liver transplantation, dystrophic calcification caused by granulomatous disorders, DNA viruses, parasitic infections, pulmonary amyloidosis, vascular calcification, the idiopathic disorder pulmonary alveolar microlithiasis, and various forms of pulmonary ossification.

Hypercalcemia in a renal transplant recipient suffering with Pneumocystis carinii pneumonia

Hypercalcemia occurs frequently after renal transplantation. Preexisting hyperparathyroidism is the most common cause of post-transplantation hypercalcemia. We describe a renal transplant recipient infected with Pneumocystis carinii pneumonia (PCP) who developed hypercalcemia, elevated 1,25-dihydroxyvitamin D, and suppressed parathyroid hormone levels. This phenomenon mimics the extrarenal production of 1,25-dihydroxyvitamin D by activated alveolar macrophages in granulomatous diseases with hypercalcemia. To the best of our knowledge, this is the first report of 1,25-dihydroxyvitamin D-mediated hypercalcemia caused by PCP in a renal transplant recipient. This entity should be included in the differential diagnosis for renal transplant recipients with hypercalcemia, especially in patients who develop lung infections.

Nodular Pneumocystis carinii pneumonia in SIV-infected macaques

Pneumocystis carinii (PC) pneumonia is a frequent manifestation of the acquired immunodeficiency syndrome (AIDS) in humans and macaques. An unusual nodular type of PC pneumonia was observed in two simian immunodeficiency virus (SIV)-inoculated rhesus macaques (Macaca mulatta). These animals developed clinical signs of simian AIDS, including anorexia, weight loss, dyspnea, and collapse. Grossly, both animals had multifocal tan-white nodules 1-10 mm in diameter scattered throughout the lungs. One animal had similar nodules involving the diaphragm and thoracic wall. The lungs were characterized by severe PC pneumonia with numerous large nodules consisting of foamy material that compressed adjacent tissue. The nodules had central areas of necrosis and lysis of alveolar septa. Varying degrees of necrotizing vasculitis were observed in areas of nodular PC pneumonia. The presence of PC in intra-alveolar spaces and nodular lesions was confirmed by immunohistochemistry. No evidence of other agents, including viral inclusions, bacteria, fungi, and lung mites, was detected. The animal with the most severe nodular PC pneumonia had vascular involvement with extrapulmonary spread to the diaphragm, thoracic wall, and regional lymph nodes. This unusual type of nodular PC pneumonia has been rarely seen in human AIDS patients.

Pneumocystis carinii

Improved understanding of Pneumocystis carinii, in particular the widespread use of chemoprophylaxis, has resulted in a declining incidence of infection in patients infected with HIV since the late 1980s. Despite these advances, P. carinii pneumonia continues to represent an important cause of pulmonary disease in HIV-seropositive individuals who do not receive chemoprophylaxis or when breakthrough episodes occur. This article reviews the history, biology, clinical manifestations, prognostic markers, therapy, and chemoprophylaxis of P. carinii pneumonia in HIV-seropositive patients.

Pulmonary pathology in AIDS: atypical Pneumocystis carinii infection and lymphoid interstitial pneumonia

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Exploration of the pulmonary circulation. Festschrift to Professor Donald Heath

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Granulomatous Pneumocystis carinii pneumonia: DNA amplification studies on bronchoscopic alveolar lavage samples

Three HIV positive subjects presented with symptoms and radiographic changes suggestive of Pneumocystis carinii pneumonia. Methenamine silver staining of bronchoscopic alveolar lavage (BAL) fluid was negative (from one sample in one patient and two samples in the other two patients). Open lung biopsy was performed because of uncertain clinical progress and diagnosis; all three patients were found to have multiple pulmonary granulomata encasing numerous P carinii organisms. DNA amplification, using P carinii specific oligonucleotides, was performed on stored bronchoscopic BAL samples. P carinii specific amplification product was detected by ethidium bromide staining after electrophoretic separation on agarose gel in one case, and by the more sensitive technique of oligohybridisation in all three cases. In granulomatous P carinii pneumonia organisms are rarely identified in bronchoscopic alveolar lavage samples using histochemical staining, but are detectable by DNA amplification, although not at levels which can be readily distinguished from low, subclinical infection.

Case report: hypercalcemia in a patient with AIDS and Pneumocystis carinii pneumonia

Pneumocystis carinii infection is commonly seen in patients infected with HIV, and there is evidence of macrophage involvement in the disease process. Macrophage dysfunction can result in abnormal vitamin D metabolism as is often seen in a granulomatous disease such as sarcoidosis. This article describes a patient with AIDS who had P. carinii pneumonia and hypercalcemia and had elevated 1,25-dihydroxyvitamin D levels, the first such reported case in the literature. There was no other evidence of a granulomatous disease such as sarcoidosis or tuberculosis to account for this. It is suggested that the increase in 1,25-dihydroxyvitamin D level was secondary to P. carinii induced macrophage dysfunction. As the patient's P. carinii pneumonia resolved, his 1,25 dihydroxyvitamin D level normalized along with the resolution of hypercalcemia.

Histologically atypical Pneumocystis carinii pneumonia

BACKGROUND

Infection with Pneumocystis carinii typically results in a pneumonia which histologically is seen to consist of an eosinophilic foamy alveolar exudate associated with a mild plasma cell interstitial infiltrate. Special stains show that cysts of P carinii lie within the alveolar exudate. Atypical histological appearances may occasionally be seen, including a granulomatous pneumonia and diffuse alveolar damage. In these patients the clinical presentation may be atypical and results of investigations negative unless lung biopsies are performed and tissue obtained for histological examination.

METHODS

The incidence and mode of presentation of histologically atypical pneumocystis pneumonia was studied in a cohort of HIV-I antibody positive patients.

RESULTS

Over a 30 month period 138 patients had pneumocystis pneumonia, of whom eight (6%) had atypical histological appearances which were diagnosed (after negative bronchoalveolar lavage) by open lung biopsy in five, percutaneous biopsy in one, and at post mortem examination in two. Atypical appearances included granulomatous inflammation in four patients, "pneumocystoma" in two (one also had extrapulmonary pneumocystosis), bronchiolitis obliterans organising pneumonia in one patient, diffuse alveolar damage and subpleural cysts in one (who also had intrapulmonary cytomegalovirus infection), and extrapulmonary pneumocystosis in two patients.

CONCLUSIONS

Various atypical histological appearances may be seen in pneumocystis pneumonia. Lung biopsy (either percutaneous or open) should be considered when bronchoalveolar lavage is repeatedly negative and evidence of P carinii should be sought, by use of special stains, in all lung biopsy material from HIV-I antibody positive patients.

Pneumocystis carinii pneumonia in cancer patients

Concern has been arisen about the recently reported increasing incidence of PCP in patients with cancer and the potential transmissibility of this infection. Whether or not there is an increase in the incidence of P. carinii infections, PCP should be considered in the differential diagnosis of pulmonary infiltrates in bone marrow transplant recipients, in patients with hematologic neoplasms and in patients with primary or metastatic brain neoplasms. Intensity of immunosuppression plays a crucial role, especially long-term (> 2 months) corticosteroid treatment. PCP is usually manifested clinically during augmentation or during tapering of corticosteroid dose. Thus, if the chest radiograph of a high-risk patient shows diffuse infiltrates, bronchoscopy and bronchoalveolar lavage should be done immediately. Treatment options are the same as for the AIDS population, except that TMP-SMX is tolerated better in non-AIDS patients. The role of supportive care, including mechanical ventilation in such patients should not be underestimated. Oral therapy with dapsone-trimethoprim or with atovaquone, can be as effective as conventional therapy in mild disease, permitting treatment on an outpatient basis. PCP is often preventable and our understanding has improved about when prophylaxis should be initiated. In the future, the emergence of new technologies for diagnosis and of new agents for treatment and prophylaxis, will bring us closer to the goal of controlling this serious infection.

Hypertrophic pulmonary osteoarthropathy associated with granulomatous Pneumocystis carinii pneumonia in AIDS

A case of hypertrophic pulmonary osteoarthropathy (HPOA) in a HIV-infected patient with granulomatous Pneumocystis carinii pneumonia is described. This is the third case of HPOA associated with AIDS reported in the literature. Granulomatous P. carinii pneumonia is an unusual manifestation of P. carinii infection. Surgical treatment of this condition may lead to the dramatic spread of P. carinii causing a fulminant course with fatal outcome.

Yield of bronchoscopy for the diagnosis of tuberculosis in patients with human immunodeficiency virus infection

The efficacy of bronchoscopy for the diagnosis of tuberculosis in patients infected with human immunodeficiency virus (HIV) has not been systematically evaluated. We therefore compared the diagnostic yield of bronchoscopy in 67 HIV-infected and 45 non-HIV-infected patients with culture-proven pulmonary tuberculosis. In all cases, acid-fast smears of sputum were negative or not obtained prior to bronchoscopy. Prebronchoscopic sputum culture yielded Mycobacterium tuberculosis in 34 (89 percent) of 38 HIV-infected patients and 26 (93 percent) of 28 non-HIV-infected patients from whom specimens were obtained. Bronchoscopy provided an early diagnosis of tuberculosis (positive acid-fast smear or granulomata on biopsy) in 23 (34 percent) of the HIV-infected patients and 20 (44 percent) of the patients without HIV infection. The sensitivities of the acid-fast smear and of mycobacterial culture of bronchoscopic specimens and postbronchoscopic sputum were similar in patients with or without HIV infection. In HIV-infected patients, granulomatous inflammation was noted on transbronchial biopsy in 11 (19 percent) of 59 patients with HIV infection, compared to 16 (43 percent) of 37 patients without HIV infection (p = 0.01). Nevertheless, transbronchial biopsy provided the exclusive means for an early diagnosis of tuberculosis in six (10 percent) of 59 HIV-infected patients. We conclude that the yield of bronchoscopy for the diagnosis of pulmonary tuberculosis in HIV-infected patients is similar to that in patients without HIV infection, and that transbronchial biopsy provides incremental diagnostic information not available from evaluation of sputum or bronchoalveolar lavage fluid.

Inflammatory responses to Pneumocystis carinii in mice selectively depleted of helper T lymphocytes

Pneumocystis carinii is the most important pulmonary pathogen in patients with the acquired immunodeficiency syndrome, but host defenses against P. carinii are not well characterized. We recently reported an experimental model of P. carinii infection, in which mice selectively depleted of CD4+ lymphocytes develop pulmonary infection after inoculation with P. carinii. In the current study, we compared lung inflammatory responses to P. carinii inoculation in CD4-depleted mice and in normal mice in order to further characterize host defenses against P. carinii. We hypothesized that depletion of CD4+ lymphocytes would prevent recruitment and activation of inflammatory cells in the lungs of these mice, allowing progressive infection with P. carinii. We found that CD4-depleted mice were unable to recruit CD4+ lymphocytes into their lungs and developed progressive infection with P. carinii, but mounted exuberant inflammatory responses to the organisms. These inflammatory responses were characterized by perivascular infiltration with mononuclear cells, increases in cell numbers in bronchoalveolar lavage (particularly CD8+ lymphocytes), and activation of alveolar macrophages (enhanced Ia antigen expression). In contrast, normal mice recruited CD4+ lymphocytes into their lungs and eliminated organisms with only minimal inflammatory responses. We conclude that depletion of CD4+ lymphocytes does not prevent the recruitment and activation of inflammatory cells in the lung. These inflammatory responses occur by mechanisms independent of CD4+ lymphocytes and are insufficient to provide effective host defense against P. carinii.

Pneumocystis carinii, an opportunist in immunocompromised patients

Pneumocystis carinii has been recognized as a cause of pneumonia in immunocompromised patients for over 40 years. Until the 1980s, Pneumocystis pneumonia (pneumocystosis) was most often seen in patients undergoing chemotherapy for malignancy or transplantation. Infection could be prevented by trimethoprim-sulfamethoxazole prophylaxis; thus, it was an uncommon clinical problem. With the onset of the AIDS epidemic, Pneumocystis pneumonia has become a major problem in the United States because it develops in approximately 80% of patients with AIDS and because almost two-thirds of patients have adverse reactions to anti-Pneumocystis drugs. Thus, physicians and laboratories in any community may be called upon to diagnose and provide care for patients with Pneumocystis pneumonia. The classification of the organism is currently controversial, but it is either a protozoan or a fungus. P. carinii appears to be acquired during childhood by inhalation and does not cause clinical disease in healthy persons but remains latent. If the person becomes immunosuppressed, the latent infection may become activated and lead to clinical disease. Damage of type I pneumocytes by Pneumocystis organisms leads to the foamy alveolar exudate which is characteristic of the disease. Diagnosis is established by morphologic demonstration of Pneumocystis organisms in material from the lungs. Current efforts to find better anti-Pneumocystis drugs should provide more effective therapy and prophylaxis.

An improved noninfectious murine skin model of organized granulomatous inflammation

An improved model of granulomatous inflammation in skin was developed by second passage skin grafting of isolated, lyophilized skin granulomas, originally elicited in naive mice by inoculations of lyophilized hepatic schistosome egg granulomas. The tissue reaction is caused by a single exposure to a noninfectious, acellular granulomagenic stimulus and occurs in healthy mice free of systemic disease. The model should prove useful for isolation of granuloma initiation factor(s). Furthermore, because there is a time lag before new granuloma formation begins, a window exists for analytical dissection of the initiation process. In this study we described the responses of host cells by autoradiography, and light and electron microscopy. The activity of angiotensin-converting enzyme and proline-specific endopeptidase showed a modulation during granuloma formation. In addition we found that severe immunosuppression with high dose cyclosporine therapy did not alter granuloma formation, supporting the idea that initiation of organized granulomas is T-cell independent.

Granulomatous Pneumocystis carinii pneumonia in a patient with the acquired immunodeficiency syndrome

A patient with an unusual granulomatous response to infection with Pneumocystis carinii is described. The diagnosis was made by open lung biopsy after two negative bronchoalveolar lavages.

Bronchoalveolar lavage via a modified stomach tube in intubated patients with the acquired immunodeficiency syndrome and diffuse pneumonia

A simple non-bronchoscopic bronchoalveolar lavage method was used in 30 patients with the acquired immunodeficiency syndrome undergoing assisted ventilation for respiratory failure. A modified Argyle Levin stomach tube was passed via the endotracheal tube and lavage performed. The lavage was well tolerated and performed quickly and easily, required little training, and had a high degree of sensitivity (73%--a diagnosis in 22 of the 30 cases).