Pathologic features of the lung in the immunocompromised host

Pleural effusion as the initial clinical presentation in disseminated cryptococcosis and fungaemia: an unusual manifestation and a literature review

BACKGROUND

Cryptococcus neoformans infection usually presents as chronic meningitis and is increasingly being recognized in immunocompromised patients. Presentation with pleural effusion is rare in cryptococcal disease; in fact, only 4 cases of pleural effusion as the initial clinical presentation in cryptococcosis have been reported in English-language literature to date. We report the first case of pleural effusion as the initial clinical presentation in a renal transplant recipient who was initially misdiagnosed with tuberculous pleuritis but who then developed fungaemia and disseminated cryptococcosis. The examination of this rare manifestation and the accompanying literature review will contribute to increased recognition of the disease and a reduction in misdiagnoses.

CASE PRESENTATION

We describe a 63-year-old male renal transplant recipient on an immunosuppressive regimen who was admitted for left pleural effusion and fever. Cytological examinations and pleural fluid culture were nonspecific and negative. Thoracoscopy only found chronic, nonspecific inflammation with fibrosis in the pleura. After empirical anti-tuberculous therapy, the patient developed an elevated temperature, a severe headache and vomiting and fainted in the ward. Cryptococci were specifically found in the cerebrospinal fluid following lumbar puncture. Blood cultures were twice positive for C. neoformans one week later. He was transferred to the respiratory intensive care unit (RICU) immediately and was placed on non-invasive ventilation for respiratory failure for 2 days. He developed meningoencephalitis and fungaemia with C. neoformans during hospitalization. He was given amphotericin B liposome combined with 5-flucytosine and voriconazole for first 11 days, then amphotericin B liposome combined with 5-flucytosine sustained to 8 weeks, after that changed to fluconazole for maintenance. His condition improved after antifungal treatment, non-invasive ventilation and other support. Further pathological consultation and periodic acid-Schiff staining revealed Cryptococcus organisms in pleural sections, providing reliable evidence for cryptococcal pleuritis.

CONCLUSION

Pleural effusion is an unusual manifestation of cryptococcosis. Cryptococcal infection must be considered in the case of patients on immunosuppressives, especially solid-organ transplant recipients, who present with pleural effusion, even if pleural fluid culture is negative. Close communication between the pathologist and the clinician, multiple special biopsy section stains and careful review are important and may contribute to decreasing misdiagnosis.

Diagnostic approach of pulmonary disease in the HIV negative immunocompromised host

The advances in medicine have resulted in increasing number of immunocompromised patients with complications related to their underlying disease or the treatment of these conditions. Pulmonary infectious and non-infectious conditions are a major cause of morbidity and mortality in these patients, and represent a diagnostic challenge. This article reviews the major conditions causing pulmonary symptoms in the HIV negative immunocompromised host. It also discusses the role of the different diagnostic methods, including the recent advances in non-invasive studies, in reaching a diagnosis of pulmonary disease in this patient population.

Autopsy-proven causes of death in lungs of patients immunocompromised by secondary interstitial pneumonia

PURPOSE

To present the more frequent associations found in autopsies of immunocompromised patients who developed secondary interstitial pneumonia as well as the risk of death (odds ratio) in having specific secondary interstitial pneumonia according to the cause of immunocompromise.

METHOD

From January 1994 to March 2004, 17,000 autopsies were performed at Hospital das Clínicas, São Paulo University Medical School. After examining the pathology report review, we selected 558 of these autopsies (3.28%) from patients aged 15 years or more with primary underlying diseases who developed radiologically diffuse infiltrates of the lung during their hospital course and died after secondary interstitial pneumonia (bronchopneumonia, lobar pneumonia, interstitial pneumonia, diffuse alveolar damage, pulmonary recurrence of underlying disease, drug-induced lung disease, cardiogenic pulmonary edema, or pulmonary embolism). Histology slides were reviewed by experienced pathologists to confirm or not the presence of secondary interstitial pneumonia. Statistical analysis included the Fisher exact test to verify any association between histopathology and the cause of immunocompromise; a logistic regression was used to predict the risk of death for specific histological findings for each of the independent variables in the model.

RESULTS

Secondary interstitial pneumonia was histologically represented by diffuse interstitial pneumonitis ranging from mild nonspecific findings (n = 213) to a pattern of diffuse alveolar damage (n = 273). The principal causes of immunocompromise in patients with diffuse alveolar damage were sepsis (136 cases), neoplasia (113 cases), diabetes mellitus (37 cases), and transplantation (48 cases). A high risk of death by pulmonary edema was found for patients with carcinoma of colon. Similarly, in patients with lung cancer or cachexia, A high risk of death by bronchopneumonia (OR = 3.6; OR = 2.6, respectively) was found. Pulmonary thromboembolism was associated with an appreciable risk of death (OR = 2.4) in patients with arterial hypertension. The risk of death was also high in patients presenting hepatic cancer (OR = 2.5) or steroid therapy (OR = 2.4) who developed pulmonary hemorrhage as the histological pattern of secondary interstitial pneumonia . The risk of death by lung metastasis was also elevated (OR = 1.6) for patients that were immunosuppressed after radiotherapy.

CONCLUSION

Patients with secondary immunosuppression who developed secondary interstitial pneumonia during treatment in hospital should be evaluated to avoid death by diffuse alveolar damage, pulmonary edema, bronchopneumonia, lung hemorrhage, pulmonary thromboembolism, or lung metastasis. The high-risk patients are those immunosuppressed by hematologic disease; those under steroid treatment; or those with colon or hepatic carcinoma, cachexia, or arterial hypertension.

Immunohistochemical and in situ detection of cytomegalovirus in lung autopsies of children immunocompromised by secondary interstitial pneumonia

Secondary interstitial pneumonia (SIP), a disease affecting patients immunocompromised by primary underlying diseases during their treatment in hospital, is frequently associated with cytomegalovirus (CMV) infection, a potentially treatable condition. However, in many cases, no infectious agent can be determined, and this clinical disease rapidly progresses to death. Theoretically, SIP could be caused by CMV, which may be present in such small amounts or such configuration that routine histopathological analysis or viral culture techniques cannot detect the virus. To test the hypothesis that immunohistochemistry (IH) and in situ detection by hybridization (ISH) provides more accurate results than the mere histological demonstration of CMV inclusions, these methods were applied to 37 autopsied lung sections obtained from children immunocompromised by primary underlying diseases and who died of SIP. As a result, the cases were subdivided into three groups: (1) children with SIP CMV inclusions (Diffuse alveolar damage-DAD-related) (n = 7); (2) children with SIP without classical viral inclusions (CMV-DAD-related) (n = 3); (3) children with SIP exhibiting nuclear cytopathic effect (not CMV-NSIP-related) (n = 27). In the first group, all three techniques yielded clearly positive results, whereas IH and ISH indicated that three of the children of the second group had CMV-related DAD without histological demonstration of CMV inclusions. In the third group, there were no positive CMV signals. These data indicate that DAD-related CMV infection is an important cause of SIP and of death in children immunosuppressed by primary underlying diseases, and that IH and in situ detection were more sensitive than the histological demonstration of CMV inclusions. A direct involvement of CMV in SIP exhibiting DAD is likely, but not in the non-specific interstitial pneumonia (NSIP) pattern. We conclude that all children with primary underlying diseases should be investigated for CMV SIP using sensitive IH and in situ tests in conjunction with histological routine procedures.

Pulmonary infections in immunocompromised hosts: the importance of correlating the conventional radiologic appearance with the clinical setting

The lung is one of the most frequently involved organs in a variety of complications in the immunocompromised host. Among the pulmonary complications that occur in this kind of patient, infection is the most common and is associated with high morbidity and mortality. Although chest radiography and computed tomography (CT) are essential diagnostic tools, radiologists often have difficulty in establishing the correct diagnosis on the basis of radiologic findings alone. The reasons are that the immunocompromised host is potentially susceptible to infection from many different microorganisms and that radiologic findings are seldom specific for the detection of a particular pathogen. Experience has shown that a particular clinical setting predisposes patients to infection by particular pathogens. The setting comprises (a) the specific epidemiologic or environmental exposure, (b) the type of underlying immune defect, (c) the duration and severity of immune compromise, and (d) the progression rate and pattern of the radiologic abnormality. Correlating the radiologic appearance with the clinical setting can expedite diagnosis and appropriate therapy. In this review, the authors describe the clinical settings that are helpful in choosing the radiologic approach to treatment of the immunocompromised host who presents with suspected pulmonary infection.

Acute lung disease in the immunocompromised host. Diagnostic accuracy of the chest radiograph

PURPOSE

To assess the diagnostic accuracy of the chest radiograph in the evaluation of acute pulmonary complications in immunocompromised patients.

METHODS

The study included the chest radiographs in 149 consecutive acute pulmonary complications seen in immunocompromised patients in whom a definitive diagnosis was made. Twenty-four complications were in patients with AIDS and 125 were in non-AIDS patients. The radiographs were separately reviewed in random order by two independent observers. The observers assessed pattern and distribution of radiographic findings and recorded their first-choice diagnosis.

RESULTS

The most common complication in patients with AIDS was Pneumocystis carinii pneumonia (n = 21). In the non-AIDS patients, the most common complications included invasive aspergillosis (n = 25), drug reaction (n = 21), and Pneumocystis pneumonia (n = 20). A correct first-choice diagnosis was made in 90% of patients with AIDS and 34% of non-AIDS patients. IN AIDS patients with Pneumocystis pneumonia, the correct first-choice diagnosis was made in 41 of 42 (98%) readings by the two observers. In non-AIDS patients with invasive pulmonary aspergillosis, drug reaction, and Pneumocystis pneumonia, the correct first-choice diagnosis was made in 38%, 26%, and 43% of readings, respectively.

CONCLUSION

The chest radiograph is helpful in the differential diagnosis of acute lung disease in the immunocompromised host, particularly in patients with AIDS.

Pathology of the lung in leukaemia and lymphoma: a study of 87 autopsies

Histopathological findings in the lungs in a series of autopsies on 87 patients suffering from various types of leukaemia or lymphoma who had received no treatment, or various combinations of radiotherapy, chemotherapy and bone marrow transplantation were reviewed. Thirteen untreated patients showed neoplastic infiltration (4), thromboembolism (4), infection (5) or amyloidosis (1). Seventy-two treated cases showed malignant infiltration (14), vascular damage (21), infections (32) and/or diffuse alveolar damage (47). One patient treated with local irradiation for myeloma had acute bronchopneumonia alone and another treated with [32P] for polycythaemia rubra vera had extensive thrombo-embolism of the large pulmonary vessels. Clinical and autopsy evidence of infection correlated very poorly. Non-infective pulmonary disease was a frequent finding. Bacterial, fungal or pneumocystis pneumonia particularly affected the chemotherapy and radiotherapy groups, while cytomegalovirus infection was seen only in the bone marrow transplant group. This study shows that diffuse alveolar damage is a common and important problem in patients treated with radiotherapy and chemotherapy.

Pulmonary infiltrates in immunocompromised patients. Diagnostic value of telescoping plugged catheter and bronchoalveolar lavage

The usefulness of telescoping plugged catheter (TPC) together with bronchoalveolar lavage (BAL) in the same bronchoscopic act in the diagnosis of pulmonary infiltrates was studied in 113 fiberoptic bronchoscopic examinations performed on 96 immunocompromised patients. The TPC cultures detected pulmonary bacterial infections in 25 (22 percent) cases but showed a high frequency of false positive results (12 microorganisms, 27 percent). Bronchoalveolar lavage had an overall diagnostic yield of 49 percent (53 of 113 cases). Combining TPC and BAL diagnostic values, 78 of 113 pulmonary infiltrates (69 percent) were diagnosed. The results obtained by both techniques allowed us to modify the treatment in 35 (31 percent) cases. Combined, TPC and BAL show a good diagnostic yield in immunocompromised patients with pulmonary infiltrates. Both techniques should be performed as the first approach in the evaluation of these patients, and be done in the same bronchoscopic procedure.

Viral infections in the acquired immunodeficiency syndrome

The following communication is a tripartite synopsis of the role of viral infection in the acquired immunodeficiency syndrome (AIDS). The first section describes the impact of viral opportunistic infection in AIDS; for each virus, clinical presentation and diagnosis, laboratory diagnostic approaches (with emphasis on electron microscopy), and therapeutic interventions attempted to date are discussed. The second segment explores current theories on the pathogenesis of AIDS, and describes diagnostic and therapeutic approaches to the syndrome itself. The final section catalogues ultrastructural anomalies in the cells of AIDS patients, many of which have been mistakenly identified as etiologic agents.

Pulmonary disease in the immunocompromised host. 1

With few exceptions, pulmonary complications in the immunocompromised host will proceed to death unless the clinician intercedes. The differential diagnosis of diffuse pulmonary disease in this setting includes (1) infection, most commonly from opportunistic organisms; (2) recurrence or extension of the basic underlying disease process to involve the lungs; (3) adverse pulmonary reaction to drugs; (4) a new, unrelated disease process such as cardiac pulmonary edema or pulmonary emboli; and (5) any combination of these categories. Up to a third of these patients have two or more complications, such as pneumonitis from two different opportunistic organisms or an opportunistic infection and a drug-induced pulmonary complication. An understanding of the host defense that is compromised enables the clinician to narrow the differential diagnosis. The most common types of impairment of defense mechanisms are reductions in the number of granulocytes, B-lymphocytes, or T-lymphocytes, and not uncommonly, two or all three of these types of cells are involved. Impairment of each of these cell types is associated with an increased frequency of infection by a particular group of organisms. Consequently, the clinician can be somewhat selective if empiric therapy is being considered. In the immunocompromised patient, most pulmonary complications, including drug-induced pulmonary disease and pulmonary emboli, are associated with fever that mimics an infection. Up to 25% of the pulmonary complications in these patients are noninfectious.

Interstitial pneumonitis following bone marrow transplantation: pathogenesis and therapeutic considerations

High-dose chemo-radiotherapy followed by allogeneic bone marrow transplantation has become standard treatment for a variety of hematological malignancies. Interstitial pneumonitis (IP) is a major complication after bone marrow transplantation, the incidence being approximately 50% (range 20-65%). Cytomegalovirus (CMV) is found in about half of these cases. If no infectious cause can be detected, the interstitial pneumonitis is labeled 'idiopathic'. The occurrence of CMV IP is related to the state of severe immunosuppression in combination with graft-vs-host disease (GvHD) in these patients. The most important factors contributing to idiopathic IP seem to be: chemotherapy, total-body irradiation, agents to prevent GvHD and GvHD itself. For preventing CMV IP hyperimmune globulin seems to be the most promising method at this moment. As long as the etiology of idiopathic IP remains unclear, no measures can be taken to prevent or treat this disease.

Necropsy findings in acquired immunodeficiency syndrome: a comparison of premortem diagnoses with postmortem findings

Necropsies were performed in 12 patients who fulfilled the Centers for Disease Control (CDC) criteria for acquired immunodeficiency syndrome (AIDS), and the postmortem findings were compared with the premortem diagnoses. All of the patients were men with a male sexual preference and histories of multiple episodes of venereal diseases. Four patients were intravenous drug abusers, while two abused amyl nitrate. All 12 of the patients had evidence of cellular immune deficiency at presentation. The causes of death were a variety of opportunistic infections and neoplasms. Pneumocystis carinii pneumonia was diagnosed prior to death in seven patients. Despite current therapy, all seven of those patients had persistent Pneumocystis carinii pneumonia at necropsy, as well as clinically undiagnosed cytomegalovirus infection. In addition, two cases of acid-fast infections, two of visceral candidiasis, one of pneumocystis pneumonia, one of central nervous system lymphoma, one of gram-negative bacterial pyelonephritis, and one of cutaneous aspergillosis were clinically unrecognized and untreated. Nine patients died with two or more infections. Thus, necropsy is a valuable tool for recognizing clinically undiagnosed infections and malignant disorders in AIDS.