Diagnosis of cytomegalovirus pneumonia in compromised hosts

Pneumonias in the compromised host

The choice of diagnostic modality depends on the patient's status, the expertise of the operator and pathologic resources of the hospital, and is a decision that should be guided by the infectious disease consultant and the clinicians involved in the care of the patient. Although the diagnosis must be tissue based, every attempt must be made to arrive at a tissue diagnosis as soon as possible in order to start specific therapy as soon as possible. It is as important to determine that the cause of the patient's pulmonary infiltrate is noninfectious versus infectious. Pulmonary embolic disease, CHF, ARDS, pulmonary hemorrhage, and pulmonary drug reactions may be reversible and require nonantimicrobially based therapies to treat the patient. Often clinicians are overwhelmed by differential diagnostic possibilities of exotic infectious disease pathogens and overlook easily treatable noninfectious disease mimics of pneumonia. Although differential diagnostic possibilities are great in the compromised host, clinicians should not be overwhelmed by diagnostic possibilities. Instead, clinicians should try to approach the patient syndromically, taking into account the degree and type of immunosuppression, the appearance and behavior of the infiltrates on the chest radiograph and the nature of the host defense defects and time relationships that will limit the differential diagnosis to relatively few diagnostic possibilities. The clinician can then treat empirically patients with presumed bacterial pneumonias and devise a diagnostic plan designed to arrive at a specific tissue diagnosis as soon as possible in patients who are likely to have nonbacterial infection of the lungs.

Cytomegalovirus pneumonia: high-resolution CT findings in ten non-AIDS immunocompromised patients

OBJECTIVE

To describe the HRCT findings of cytomegalovirus (CMV) pneumonia in non-AIDS immunocompromised patients

MATERIALS AND METHODS

This retrospective study involved the ten all non-AIDS immunocompromised patients with biopsy-proven CMV pneumonia and without other pulmonary infection encountered at our Medical Center between January 1997 and May 1999. HRCT scans were retrospectively analysed by two chest radiologists and decisions regarding the findings were reached by consensus.

RESULTS

The most frequent CT pattern was ground-glass opacity, seen in all patients, with bilateral patchy (n = 8) and diffuse (n = 2) distribution. Other findings included poorly-defined small nodules (n = 9) and consolidation (n = 7). There was no zonal predominance. The small nodules, bilateral in eight cases and unilateral in one, were all located in the centrilobular region. Consolidation (n = 7), with patchy distribution, was bilateral in five of seven patients (71%). Pleural effusion and bilateral areas of thickened interlobular septa were seen in six patients (60%).

CONCLUSION

CMV pneumonia in non-AIDS immunocompromised patients appears on HRCT scans as bilateral mixed areas of ground-glass opacity, poorly defined centrilobular small nodules, and consolidation. Interlobular septal thickening and pleural effusion are frequently associated.

Diagnosis of infectious diseases: a cytopathologist's perspective

This review explores the role of the cytopathology laboratory in the detection and presumptive identification of microorganisms. Sample procurement by exfoliation, abrasion, and aspiration techniques, as well as a variety of cytopreparatory and staining methods, is reviewed. Emphasis is placed on the utility of fine-needle aspiration as a rapid, safe, and cost-effective diagnositic procedure. The role of rapid interpretation and specimen triage is also discussed. Cytomorphologic features and staining characteristics are presented for a spectrum of microorganisms potentially encountered in the cytopathology laboratory. Pitfalls in diagnosis and the usefulness of special stains and ancillary techniques are also evaluated. The importance of communication, collaboration, and clinical correlation is stressed.

Preoperative and postoperative imaging in the surgical management of pulmonary emphysema

For patients with emphysema, imaging studies have been useful for diagnostic purposes and for preoperative patient selection for surgical intervention, such as bullectomy, lung transplantation, and LVRS. Chest radiography is useful in evaluating hyperinflation. Inspiratory and expiratory films are used to estimate diaphragmatic excursion and air-trapping. CT scan is used to evaluate the anatomy and distribution of emphysema throughout the lungs, providing information clinically unobtainable by other means. Both imaging techniques are useful for detecting other disease processes. Radionuclide lung scanning also provides an estimate of target areas, volume occupying but nonfunctioning lung. Cohort studies utilizing these imaging techniques have demonstrated associations between preoperative characteristics and postoperative outcome. The imaging studies, especially the chest radiograph, have also played an important role in postoperative management. Many other imaging options are available, such as HRCT scan, quantitative CT scan, and single photon emission CT scan. Other techniques, such as MR imaging, may play a future role as well.

Prognostic significance of pathological chest radiography in transplant patients affected by cytomegalovirus and/or pneumocystis carinii

PURPOSE

In order to evaluate the prognostic significance of chest film findings in connection with cytomegalovirus (CMV) and/or pneumocystis carinii infection (PC), a retrospective review was made of the pulmonary charts of 274 recipients of kidney and/or pancreatic grafts transplanted between April 1987 and December 1990.

MATERIAL, METHODS AND RESULTS

Positive laboratory findings for CMV and/or PC were seen in 92 patients. In 77 patients only CMV was found, 13 patients had both CMV and PC, and 2 patients had only PC. In 57 patients a chest examination was performed. The films were reviewed by 2 radiologists independently. In 32 patients normal chest film findings were seen, while 25 patients demonstrated pathological changes. Of the patients with pathological changes 3 had only pleuritis while the remaining 22 demonstrated parenchymal infiltrations. No deaths occurred among patients infected with CMV and/or PC, when the chest film findings were normal or pleuritis only was seen, but there were 9 deaths in the group of patients with parenchymal infiltrations. Of the patients who died, 2 had only CMV, 5 had both CMV and PC, and 2 had only PC. The overall mortality, regardless of radiological findings, did not exceed 3% in patients with CMV only, but increased to 38% in patients with both CMV and PC. In patients with parenchymal infiltrations the corresponding mortality figures were increased to 18% and 56%, respectively.

CONCLUSION

We conclude that a radiologically verified pneumonia related to the infectious agent influences the prognosis, and that CMV pneumonia has a better prognosis than PC pneumonia.

Cytomegalovirus pneumonia in transplant patients: CT findings

OBJECTIVE

Our goal was to assess the CT findings of cytomegalovirus (CMV) pneumonia in transplant patients.

MATERIALS AND METHODS

The study included 10 transplant patients who had chest CT scan and pathologically proven isolated pulmonary CMV infection. Five patients had bone marrow transplant and five had solid organ transplant. The CT scans were retrospectively reviewed for pattern and distribution of disease and the CT findings compared with the findings on open lung biopsy (n = 9) and autopsy (n = 1).

RESULTS

Nine of 10 patients had parenchymal abnormalities apparent at CT and 1 had normal CT scans. The findings in the nine patients included small nodules (n = 6), consolidation (n = 4), ground-glass attenuation (n = 4), and irregular lines (n = 1). The nodules had a bilateral and symmetric distribution and involved all lung zones. The consolidation was most marked in the lower lung zones.

CONCLUSION

The CT findings of CMV pneumonia in transplant patients are heterogeneous. The most common patterns include small nodules and areas of consolidation.

Systemic cytomegalovirus infection during postoperative chemoradiotherapy for malignant astrocytoma: case report with immunohistochemistry and in situ hybridization

We report a patient with a systemic cytomegalovirus (CMV) infection, which occurred during postoperative chemoradiotherapy for a malignant astrocytoma. To our knowledge, there is no report that is especially focused on the association with a CMV infection. Interstitial pneumonia and gastrointestinal bleeding, which developed suddenly during postoperative chemoradiotherapy, resulted in the patient's death. A histopathological examination of the postmortem specimens revealed numerous "owl's eye" cells containing intranuclear inclusion bodies, which were identified as CMV by immunohistochemical examination and in situ hybridization. The premortem diagnosis of CMV infection is usually difficult, because an anti-CMV titer can be nonspecifically elevated. With immunohistochemical examination and in situ hybridization, CMV in excretory or biopsy specimens can be identified and the diagnosis of CMV infection can be established. When serious pneumonia or massive gastrointestinal bleeding occurs during postoperative chemoradiotherapy, the differential diagnosis should include the possibility of CMV infection and we recommend an immunohistochemical examination and in situ hybridization for the detection of CMV.

Use of indium 111-labeled white blood cell scan in the diagnosis of cytomegalovirus pneumonia in a renal transplant recipient with a normal chest roentgenogram

Opportunistic infections are common in patients after renal transplantation. This report describes a case of cytomegalovirus pneumonia in a renal transplant recipient with a normal chest roentgenogram and normal arterial oxygenation. An abnormal 111In-white blood cell scan led to the discovery of a pulmonary source of his recurrent fevers.

Cytomegalovirus in the bronchoalveolar lavage fluid of patients with AIDS

This study investigated the significance of detecting cytomegalovirus in the bronchoalveolar lavage fluid of patients with human immunodeficiency virus infection. Bronchoscopy with BAL was performed on all patients. Lavage was examined for CMV by cytology, culture, and immunofluorescence. The lavage results were compared to clinical status at the time of bronchoscopy and the outcome of the respiratory event. Cytomegalovirus was detected in 51 percent of the BALs in the patients with HIV infection and 25 percent of the immunosuppressed patients without HIV. No association was found in the HIV infected patients between CMV and hypoxemia, abnormal chest roentgenogram, leukopenia, and increased mortality. As indicated by mortality, CMV did not significantly increase the severity of Pneumocystis carinii pneumonia. The study also suggested that CMV in BAL fluid reflected bronchopulmonary replication of the virus, and not contamination by virus in the blood. Cytomegalovirus does not appear to contribute directly to the pulmonary disease found in most patients with HIV infection.

Cytomegalovirus retinitis

Cytomegalovirus retinitis is a frequent and serious complication of various conditions, including diseases characterized by impaired immunity, such as the acquired immunodeficiency syndrome. Due to recent advances in the treatment of cytomegalovirus retinitis, accurate diagnosis and management have become increasingly important. In this review, the authors present the epidemiology, clinical features, diagnostic testing, treatment with complications, and prognosis of cytomegalovirus retinitis. A differential diagnosis is presented and the characteristic ocular lesions are illustrated.

Radiological appearances of cytomegalovirus infections

The chest and abdominal radiographs of 35 patients with cytomegalovirus (CMV) infection were reviewed. The radiological appearances of cytomegalovirus pneumonia varied widely with no pattern sufficiently characteristic to allow early differentiation of CMV from other infective agents. Spontaneous pneumothorax and pneumomediastinum were seen frequently in association with advanced CMV pneumonia. Abdominal abnormalities included bowel wall thickening, dilated bowel loops and pneumatosis intestinalis.

Respiratory complications of cardiac transplantation

The authors evaluated all respiratory complications of cardiac transplantation in a 10-year study of 94 consecutive recipients. Mean follow-up time was 20 +/- 17 months. The initial 20 patients were treated with azathioprine and prednisone, while the subsequent 74 patients received cyclosporine and prednisone. In the azathioprine group, respiratory infections accounted for 24 of 60 (40%) infections. Two-thirds of the respiratory infections occurred in the first 3 postoperative months and were generally localized processes (focal pneumonitis, nodule(s), abscess, or empyema). Gram-positive and gram-negative bacteria (8/30) and aspergillus (8/30) were the predominant pathogens. Respiratory failure occurred in 29% of infectious episodes. In the cyclosporine group, there were significantly fewer respiratory infections. There was also a reduction in the number of nonrespiratory infections; hence, the percentage of total infections due to respiratory causes, 26 of 50 (52%), was not significantly different. In contrast, however, nearly two-thirds of the respiratory infections in cyclosporine-treated patients occurred after the first 3 postoperative months, and were usually diffuse processes. Despite diffuse disease, respiratory failure was observed with similar frequency (19%). Pneumocystis carinii (9/31) and cytomegalovirus (CMV) (7/31) were the predominant pathogens. CMV pneumonitis tended to occur earlier than that due to P. carinii (2.9 +/- 1.9 mo vs. 9.8 +/- 11.2 mo, respectively), but there was considerable overlap. In comparison with infectious processes, there were 50% fewer noninfectious respiratory complications in both groups. These were primarily pleural (46%) or thromboembolic (18%) disorders. Four of five pulmonary emboli occurred in patients with intercurrent cardiorespiratory illness, and were detected only at autopsy. The authors conclude that respiratory infections account for one-half of all infections observed in cardiac transplant recipients, despite the reduced infection rate associated with the use of cyclosporine. Furthermore, respiratory infections in cyclosporine-treated patients exhibit different clinical and etiologic features than those seen in azathioprine-treated patients. Finally, occult thromboemboli may be difficult to recognize in cardiac transplant recipients because of the high incidence of coexisting cardiorespiratory disease.

Utility of airway endoscopy in the diagnosis of respiratory complications of cardiac transplantation

We evaluated 39 episodes (in 32 patients) of pulmonary parenchymal infiltrates following cardiac transplantation with fiberoptic bronchoscopy (FOB) in a prospective study of 94 consecutive recipients. Initial FOB established the diagnosis in 24/39 (62 percent) instances. Subsequent examinations included repeat FOB (five), open lung biopsy (five), needle aspiration (two), and autopsy (nine), establishing 49 diagnoses. Specific pathogens were identified in 45 instances, neoplasm in two, and idiopathic interstitial pneumonitis in two. Bronchoalveolar lavage alone yielded diagnoses in 63 percent and transbronchial biopsy and bronchial washings/brushings in 46 and 43 percent, respectively. Transbronchial biopsy suggested idiopathic interstitial pneumonitis in 17 instances, but four had spontaneous clearing, and open lung biopsy or autopsy showed alternative diagnoses (particularly CMV and Aspergillus) in 11. The main complication of FOB was moderate (25 to 100 ml) hemorrhage after transbronchial biopsy (10 percent); no severe episodes occurred despite elevated pulmonary vascular pressures. In this population of immunocompromised hosts: (1) bronchoalveolar lavage is the most sensitive bronchoscopic technique for detecting infection; (2) transbronchial biopsy is not useful in detecting CMV or Aspergillus infection; (3) pulmonary hypertension is associated with some risk of moderate but not severe hemorrhage after transbronchial biopsy.

Pneumonias in adults due to mycoplasma, chlamydiae, and viruses

Pneumonias in adults due to mycoplasma, chlamydiae, and viruses are a common clinical problem. These microorganisms contribute to the etiologies in 6-35% of all cases of pneumonia and are the sole pathogens in 1-17% of hospitalized cases. Important trends and developments in the field include the emergence of a Chlamydia psittaci strain (TWAR) that is passaged from human to human, causes a mycoplasma-like illness, and that is relatively resistant to erythromycin, the recognition of respiratory syncytial virus as a pathogen in nursing home outbreaks and in immunosuppressed adults, the continuing high lethality of fully developed influenza pneumonia, the efficacy of acyclovir and adenine arabinoside in limiting the complications of varicella-zoster virus infections, and the increasing frequency of pneumonia caused by cytomegalovirus and the severity of this disorder in highly immunosuppressed patients. Developments in the rapid diagnosis and therapy of respiratory syncytial virus infections with an aerosolized antiviral drug in children may pave the way for comparable advances in difficult pneumonias in adult patients.

The effect of biological response modifiers on chronic and latent murine cytomegalovirus infections

Host-mediated antiviral effect of 2 biological response modifiers (BRM), OK-432, and PS-K, against murine cytomegalovirus (MCMV) was evaluated in chronically or latently infected mice. In the early stage of chronic MCMV infection, the BRM-induced resistance was evidenced by decrease in infectious viruses replicated in the salivary glands and by augmented cytotoxic activity of the spleen cells against YAC-1 cells and MCMV-infected mouse embryonic fibroblasts (MEF). In the late stage of chronic MCMV infection, the BRM treatment did not eliminate MCMV from the mice, but did prevent exacerbation of MCMV infection in the salivary glands induced by administration of cyclophosphamide (CY). In mice latently infected by MCMV, BRM treatment suppressed CY-induced reactivation of MCMV in the salivary glands. It was suggested that the antiviral effect of BRM against MCMV in chronically or latently infected mice was based on activation of natural killer (NK) cells and cytotoxic T lymphocytes (CTL).

Cytomegalovirus pneumonitis and lobar consolidation

This report describes the occurrence of localized lobar consolidation caused solely by cytomegalovirus infection in two heart transplant recipients. This highly atypical and previously unreported radiographic manifestation of cytomegalovirus pneumonitis underscores the need for vigorous diagnostic evaluation of immunosuppressed patients since localized pneumonitis in the immunocompromised host does not exclude the possibility of opportunistic infection.

Cytomegalovirus

Cytomegalovirus (CMV) has emerged as an important cause of human illness. Infection with this common virus can result in asymptomatic infection, an acute “mononucleosis-like” illness, or congenital disease. It is capable of persisting in a latent state and reactivating at a later date. It can be transmitted by blood transfusion, organ transplantation, oral or genital contact, intrauterine infection, perinatal infection and perhaps casually by children in day care centers.

Historically, the first reports described “protozoan-like” cells in the organs of a fetus and a stillborn in 1904. In 1932, Farber reported the presence of inclusions in the nucleus and cytoplasm of cells in infants dying of various causes and coined the term cytomegalic inclusion disease. The urine was initially cultured in 1953 by Smith, and the subsequent development of serologic methods of diagnosis made its broad spectrum of disease more fully appreciated.

Adult respiratory distress syndrome after renal transplantation. A case report

A potentially lethal case of "air-borne" adult respiratory distress syndrome, most likely consequent to cytomegalovirus (CMV) pneumonitis, is described in a kidney transplant patient. It was characterized by confluent densities on both lung fields with peripheral zones of normal radiographic pattern and with one of the highest values of extravascular lung water reported in the literature, in the presence of a normal pulmonary capillary wedge pressure. When specific conservative therapy for curing a potentially lethal CMV pneumonitis after kidney transplantation fails, we suggest that transplantectomy should be considered.

Cytomegalovirus- and Cryptosporidium-associated acalculous gangrenous cholecystitis

A well-documented case of cytomegalovirus- and Cryptosporidium-associated cholecystitis is described in a 19-year-old heterosexual Haitian man who had the acquired immune deficiency syndrome and acute acalculous gangrenous cholecystitis associated with these pathogens. This case adds to the spectrum of the manifestations of the profoundly immunocompromised state.

Nosocomial respiratory infections

Nosocomial respiratory tract infections are major causes of excessive morbidity and mortality in US hospitals, affecting an estimated five to ten of every 1,000 patients. Patients with serious underlying diseases have an especially high risk of acquiring these infections, and that risk is magnified by exposure to respiratory therapy. Until recently, contaminated respiratory care devices were a major cause of infection, but procedures for the management of these devices have decreased their role substantially. Now, aspiration of oropharyngeal flora appears to be responsible for most cases of bacterial respiratory infections. Therefore, techniques to alter the flora of the oropharynx and to diminish the risk of aspiration are important priorities for infection control. Exposure to intensive care units (ICUs) is also a major risk factor for nosocomial pulmonary infection, and person-to-person spread of microorganisms within ICUs seems to be responsible for some of these infections. Increasing numbers of pulmonary infections are being caused by newly identified or previously uncommon pathogens, and this shift requires that traditional control techniques be reevaluated to assure that they remain relevant. Few new techniques have been developed recently to alter host susceptibility, prevent acquisition of virulent pathogens, or eradicate infectious organisms from their sources, but effective infection control programs in hospitals appear to reduce the incidence of nosocomial pulmonary infection, and implementation of these programs deserves serious consideration in all hospitals.

Intravenous trimethoprim-sulfamethoxazole therapy for Pneumocystis carinii pneumonia

Twenty-nine immunocompromised patients were treated with intravenous trimethoprim-sulfamethoxazole for possible Pneumocystis carinii pneumonia. The diagnosis was established in 15 severely hypoxemic patients with lymphoreticular malignancy or cardiac transplants by open lung biopsy or transthoracic needle aspirate. In 13 (87 percent) of the 15, the response to therapy was rapid. They became afebrile in a mean of 2.1 days, showed improved arterial blood oxygenation in 4.7 days and improvements on the chest roentgenogram in 4.3 days. Eight (53 percent) of the 15 survived and were clinically cured. Five other patients with documented P. carinii infection improved clinically but subsequently died of other causes. Postmortem examination in these showed no P. carinii cysts. Two patients with P. carinii pneumonia died soon after therapy was started and had P. carinii cysts in lung tissue at autopsy. The combined clinical and microbiologic response of 87 percent equals or exceeds that of other reported treatment regimens. Intravenous trimethoprim-sulfamethoxazole may, therefore, be the most ideal therapy for severely ill adults with P. carinii pneumonia. Second lung biopsies in 12 patients on therapy showed that P. carinii cysts were rarely found after several days of treatment. This suggests that lung tissue may be falsely negative for P. carinii cysts in persons treated empirically but who later undergo lung biopsy.

Successful treatment with acyclovir of an immunodeficient patient infected simultaneously with multiple herpesviruses

A patient with recurrent simultaneous chronic infections, including cytomegalovirus pneumonia, disseminated zoster and perineal herpes simplex infection, whose immune responses were deficient (immunodeficient), is presented. Following treatment with acyclovir (19-(2-hydroxyethoxymethyl)guanine), this patient had a rapid remission of these viral infections. The patient's clinical improvement is remarkable considering the duration of the viral infections and the continued immune deficiency. Acyclovir appears to act by a highly selective activation by and inhibition of viral enzymes. Prospective trials of this agent in immunosuppressed patients with herpes virus infections seem warranted.

Replication of murine cytomegalovirus in lung macrophages: effect of phagocytosis of bacteria

Murine cytomegalovirus was found to replicate in lung and peritoneal macrophages of both CF-1 and BALB/c mice in vitro. Cytopathic changes typical of cytomegalovirus infection, including intranuclear inclusions, developed within the infected cells and eventually resulted in death of infected macrophages. Viral antigens were demonstrable by indirect immunofluorescence microscopy, and morphologically typical herpesvirus particles were observed in both nuclei and cytoplasm of murine cytomegalovirus-infected macrophages. Within 24 h after infection, at which time there was expression of viral antigens but no marcophage death, murine cytomegalovirus-infected macrophages demonstrated marked inhibition of phagocytosis of Staphylococcus aureus. Direct inhibition of macrophage function by cytomegalovirus infection in vivo could impair pulmonary defenses and may account in part for the frequent association of cytomegalovirus infection with other infectious agents.

Acute cytomegalovirus infections in leukemic mice

Mice infected with 2 x 10(3) plaque-forming units of mouse cytomegalovirus (MCMV) 3 days after receiving 300 to 400 spleen focus-forming units of Friend leukemia virus developed a more severe MCMV infection than did normal animals. Increased severity was demonstrated by the increased amounts of MCMV recoverable from the salivary glands of leukemic mice 1 to 5 weeks postinfection. In addition, the difference in the number of virus isolations from the kidneys, spleens, livers, and lungs of animals (74 to 120) coinfected with MCMV and Friend leukemia virus compared with animals (49 of 120) infected with MCMV alone was significant (P less than 0.01). Both the 50% lethal dose and 50% infectious dose of MCMV in leukemic mice were lower than in normal animals. MCMV and Friend leukemia virus appear to interact by suppressing the ability of infected spleen cells to respond to mitogen-induced stimulation. The observations of increased severity of MCMV infections in leukemic mice closely parallel the situation observed in human leukemia patients who are at an increased risk of disease due to human cytomegalovirus infections. This mouse model may be useful in assessing the effect of antiviral (cytomegalovirus) therapy.

Adenovirus infection in the immunocompromised patient

Illness associated adenovirus infection is described in 15 immunocompromised patients. Patients were immunocompromised by severe underlying disease, immunosuppressive or corticosteroid therapy or by age (prematurity). Evidence of adenovirus infection was obtained by either viral isolation or, in two cases, characteristic adenovirus inclusion bodies at postmortem study. All clinical illness was associated with high fever (temperature greater than 39 degrees C). Eighty per cent of the patients had severe systemic complaints including malaise, lethargy, fatigue and night sweats; a similar number of gastrointestinal symptoms. Pulmonary complaints were described in 11 of 15 cases and included cough (67 per cent) and tachypnea (53 per cent). Roentgenologic evidence of pneumonia was demonstrated in 12 of 15 patients (80 per cent). Elevation of serum hepatic enzyme levels (serum glutamic pyruvic transaminase (SGPT)) occurred in eight of 11 patients (73 per cent) and was moderate to severe (serum glutamic pyruvic transaminase greater than 450 IU/liter) in five of 11 (45 per cent). Nine patients died; seven after a rapid downhill course and two after a prolonged illness. Evidence of adenovirus infection microscopically by autopsy in the lung, liver or both is demonstrated in four patients with fulminant systemic illness. Adenovirus infection should be considered in the etiology of severe overwhelming illness in the immunocompromised host.

Adverse effects of cytomegalovirus vaccination in mice

Studies of live attenuated cytomegalovirus (CMV) vaccine have recently been initiated in man. The possibilities of latent infection and disease resulting from reactivation of vaccine virus are major concerns. Because markers for attenuation of tissue culture-passaged mouse CMV (MCMV) exist, studies of potential adverse effects of vaccination were initiated in mice. Plaque-purified MCMV was passed 12 times in cell culture ("vaccine virus") and shown to be attenuated by virtue of loss of lethality and diminished replication in reticuloendothelial organs of normal mice. Although subcutaneous inoculation of 10(5) plaque-forming units of wild virus was lethal for mice immunosuppressed with antilymphocyte serum (18/18 died), "vaccine MCMV" killed only 3/18 (P < 0.05) and was thus shown to be highly attenuated even in immunosuppressed animals. 4 mo after subcutaneous inoculation of vaccine MCMV, no infectious virus was detectable in the tissues of normal C(3)H mice. However, immunosuppression with anti-lymphocyte serum and cortisone caused MCMV reactivation, dissemination, and wide-spread cytomegalic inclusion disease in 19 of 20 animals. Characterization of the reactivating virus recovered from salivary glands indicated that reversion to virulence had occurred. Thus, vaccine MCMV, although markedly attenuated initially, established latent infection, reactivated after immunosuppression, and reverted to virulence, at least in salivary gland tissue. These data from the murine model substantiate the need for careful surveillance and virologic study of patients given experimental CMV vaccine.

Adult pulmonary cytomegalic inclusion disease: report of a case

A case is presented of pulmonary cytomegalic inclusion disease in adult. The condition was only diagnosed post mortem. A detailed description of the inclusions and inclusion-bearing cells is given. Histochemical observations which reveal an outer and inner zone to the intranuclear inclusion body are confirmed. Electron microscopy shows the viral basis of the infection. The morphology of the virus particles is compatible with a herpesvirus infection.

Cytomegalovirus granulomatous hepatitis

Three patients with granulomatous hepatitis due to cytomegalovirus are described. They are compared to the three previously described patients with this disease, and their clinical and serologic characteristics are discussed. Similarities and differences between infectious mononucleosis (Epstein-Barr virus) and cytomegalovirus infections are adduced. That cytomegalovirus may be a cause of granulomatous hepatitis in the adult is stressed.

Cell-mediated immunity to cytomegalovirus in patients receiving immunosuppressive therapy

Employing the techniques of complement-fixation (CF), immunofluorescence (IF), and in vitro lymphocyte transformation (LTF), the humoral antibody response and cell-mediated immune (CMI) response to cytomegalovirus (CMV) were studied in the serum and peripheral blood lymphocytes in 19 normal children (controls) and 23 patients with renal disease who were receiving immunosuppressive therapy or undergoing hemodialysis. The LTF activity was determined by the whole blood microassay using two strains of CMV (AD-169 and Davis) and phytohemagglutinin (PHA). The antibody level responses to CMV in different groups of subjects were generally similar. The LTF response to PHA as evidenced by delta cpm activity was moderately depressed in immunosuppressed and hemodialyzed subjects compared to the response observed in the controls. The mean delta cpm activities in response to AD-169 and Davis strains of CMV in seropositive immunosuppressed patients were about one-fifth and one-third lower respectively than those of seropositive normal controls. These observations suggest that an impairment of CMV specific cellular immunity may be an important mechanism underlying the increased susceptibility to CMV infections in patients with chronic renal disease who receive immunosuppressive therapy.

A comparison of complement fixation, indirect immunofluorescence for viral late antigens, and anti-complement immunofluorescence tests for the detection of cytomegalovirus specific serum antibodies

It was shown that, on average, the titres of the sera obtained by both the anti-complement immunofluorescence (ACIF) and indirect immunofluorescence for viral late antigens (IFA-LA) procedures were approximately eight times higher than those obtained by complement fixation. There was no significant difference between the mean ACIF and IFA-LA titres, but the former method was preferred because it was not affected by non-specific staining. When 406 sera were screened for the presence or absence of antibodies, only five sera (1.2%) gave discordant results with the three tests. None of the tests could detect all of the sera that contained specific antibodies while each test detected over 98% of these sera. Thus, the increased sensitivity of the immunofluorescence procedures did not result in an appreciably increased rate of detection of cytomegalovirus seropositive sera.

Role of infection in the death of children with acute lymphoblastic leukaemia

Twenty-four consecutive deaths from a total of 70 children receiving treatment for acute lymphoblastic leukaemia (ALL) have been reviewed. An attempt has been made to ascribe the cause of death to either infection, haemorrhage, the leukaemia itself, or a combination of these factors. No child was free of infection at death. Infection, with or without haemorrhage, was responsible for the deaths of all 15 children whose leukaemia had not relapsed. Although infection was present at death in all 9 children whose leukaemia had relapsed, the leukaemia process itself was also a major contributing factor. Viruses were associated with death in many of the children and may be emerging as important pathogens in children with ALL. Familiarity with a protocol may be an important factor in the prevention of fatal infections in such children. Centralization of treatment is necessary if this expertise is to be acquired.