Long-term sequelae after recovery from cytomegalovirus pneumonia in allogeneic bone marrow transplant recipients

Impairment of lung diffusion capacity-a new consequence in the long-term childhood leukaemia survivors

Childhood leukaemia survivors (CLS) are known to have developed long-term impairment of lung function. The reasons for that complication are only partially known. The aims of this study were to assess pulmonary function in CLS and identify (1) risk factors and (2) clinical manifestations for the impairment of airflow and lung diffusion. The study group included 74 CLS: 46 treated with chemotherapy alone (HSCT−), 28 with chemotherapy and haematopoietic stem cell transplantation (HSCT+), and 84 healthy subjects (control group (CG)). Spirometry and diffusion limit of carbon monoxide (DLCO) tests were performed in all subjects. Ten (14%) survivors had restrictive, five (7%) had obstructive pattern, and 47 (66%) had reduced DLCO. The age at diagnosis, type of transplant, and type of conditioning regimen did not significantly affect the pulmonary function tests. The DLCO%pv were lower in CLS than in CG (p < 0.03) and in the HSCT+ than in the HSCT− survivors (p < 0.05). The pulmonary infection increased the risk of diffusion impairment (OR 5.1, CI 1.16–22.9, p = 0.019). DLCO was reduced in survivors who experienced CMV lung infection (p < 0.001). The main symptom of impaired lung diffusion was poor tolerance of exercise (p < 0.005). The lower lung diffusion capacity is the most frequent abnormality in CLS. HSCT and pulmonary infection, in particular with CMV infection, are strong risk factors for impairment of lung diffusion capacity in CLS. Clinical manifestation of DLCO impairment is poor exercise tolerance. A screening for respiratory abnormalities in CLS seems to be of significant importance.

Reduced Mortality of Cytomegalovirus Pneumonia After Hematopoietic Cell Transplantation Due to Antiviral Therapy and Changes in Transplantation Practices

BACKGROUND

Despite major advances in the prevention of cytomegalovirus (CMV) disease, the treatment of CMV pneumonia in recipients of hematopoietic cell transplant remains a significant challenge.

METHODS

We examined recipient, donor, transplant, viral, and treatment factors associated with overall and attributable mortality using Cox regression models.

RESULTS

Four hundred twenty-one cases were identified between 1986 and 2011. Overall survival at 6 months was 30% (95% confidence interval [CI], 25%-34%). Outcome improved after the year 2000 (all-cause mortality: adjusted hazard ratio [aHR], 0.7 [95% CI, .5-1.0]; P = .06; attributable mortality: aHR, 0.6 [95% CI, .4-.9]; P = .01). Factors independently associated with an increased risk of all-cause and attributable mortality included female sex, elevated bilirubin, lymphopenia, and mechanical ventilation; grade 3/4 acute graft-vs-host disease was associated with all-cause mortality only. An analysis of patients who received transplants in the current preemptive therapy era (n = 233) showed only lymphopenia and mechanical ventilation as significant risk factors for overall and attributable mortality. Antiviral treatment with ganciclovir or foscarnet was associated with improved outcome compared with no antiviral treatment. However, the addition of intravenous pooled or CMV-specific immunoglobulin to antiviral treatment did not seem to improve overall or attributable mortality.

CONCLUSIONS

Outcome of CMV pneumonia showed a modest improvement over the past 25 years. However, advances seem to be due to antiviral treatment and changes in transplant practices rather than immunoglobulin-based treatments. Novel treatment strategies for CMV pneumonia are needed.

Susceptibility to cytomegalovirus infection may be dependent on the cytokine response to the virus

BACKGROUND

Cytomegalovirus (CMV) infection is an important cause of morbidity and mortality in an immunocompromised host. Pulmonary infection with CMV results in an inflammatory response, which includes the local production of cytokines. Cytokine production stimulated by CMV infection serves to activate a series of immunologic responses involved in viral clearance. Previous work has demonstrated that different mouse strains express variable sensitivity to CMV infection.

METHODS

Using mouse strains that express sensitive (BALB/cj) and resistant (C57BL/6) CMV phenotypes, we asked whether the differences in susceptibility to infection were caused by differences in pulmonary cytokine production after intraperitoneal infection with CMV.

RESULTS

C57 mice demonstrated a higher total bronchoalveolar lavage (BAL) and BAL lymphocyte count at 3 and 7 days after intraperitoneal infection compared with BALB mice. There were no differences in BAL cytokine production; however, we were able to demonstrate differences in CMV DNA load in the lungs of BALB mice compared with that of C57 mice. In addition, there appeared to be increased whole-lung production of the TH2 cytokine IL-10 in the BALB mice versus the C57 mice.

CONCLUSIONS

This observation suggests that the genetic susceptibility to CMV infection may, in part, be regulated by differences in cytokines production within the local environment.

Murine model of interstitial cytomegalovirus pneumonia in syngeneic bone marrow transplantation: persistence of protective pulmonary CD8-T-cell infiltrates after clearance of acute infection

Interstitial pneumonia (IP) is a severe organ manifestation of cytomegalovirus (CMV) disease in the immunocompromised host, in particular in recipients of bone marrow transplantation (BMT). Diagnostic criteria for the definition of CMV-IP include clinical evidence of pneumonia together with CMV detected in bronchoalveolar lavage or lung biopsy. We have used the model of syngeneic BMT and simultaneous infection of BALB/c mice with murine CMV for studying the pathogenesis of CMV-IP by controlled longitudinal analysis. A disseminated cytopathic infection of the lungs with fatal outcome was observed only when reconstituting CD8 T cells were depleted. Neither CD8 nor CD4 T cells mediated an immunopathogenesis of acute CMV-IP. By contrast, after efficient hematolymphopoietic reconstitution, viral replication in the lungs was moderate and focal. The histopathological picture was dominated by preferential infiltration of CD8 T cells confining viral replication to inflammatory foci. Notably, after clearance of acute infection, CD62L(lo) and CD62L(hi) subsets of CD44(+) memory CD8 T cells were found to persist in lung tissue. One can thus operationally distinguish an early CMV-positive IP (phase 1) and a late CMV-negative IP (phase 2). According to the definition, phase 2 histopathology would not be diagnosed as a CMV-IP and could instead be misinterpreted as a CMV-induced immunopathology. We document here that phase 1 as well as phase 2 pulmonary CD8 T cells are capable of exerting effector functions and are effectual in protecting against productive infection. We propose that antiviral "stand-by" memory-effector T cells persist in the lungs to prevent virus recurrence from latency.