Severe cytomegalovirus pneumonitis in HIV infected patients with higher than average CD4 counts

Progressive Lung Consolidation in HIV Amidst the COVID-19 Pandemic: Evaluating Probable Cytomegalovirus Pneumonia and the Importance of Early Empirical Treatment

We present the case of a young male who was diagnosed with HIV in 2012. However, his initiation of antiretroviral therapy (ART) was delayed until 2018 due to issues related to his acceptance and acknowledgment of the disease. In April 2021, the patient presented with hemoptysis, shortness of breath, and constitutional symptoms. Initial extensive workup for tuberculosis (TB) and other respiratory pathogens returned negative. Despite this, he was treated for smear-negative pulmonary TB and pneumocystis pneumonia (PCP) and was subsequently discharged. He then had recurrent hospital admissions due to worsening respiratory symptoms, with short intervals between recovery and recurrence. Each admission saw an increase in his oxygen requirements. Throughout these hospitalizations, tests for coronavirus disease 2019 (COVID-19) were consistently negative. TB and PCP treatment continued throughout his admissions. Despite various treatments, his condition continued to deteriorate. A DNA polymerase chain reaction (DNA PCR) test for cytomegalovirus (CMV) was eventually conducted. Unfortunately, the patient succumbed to progressive respiratory failure, and the CMV DNA PCR returned positive a week after his death. In the era of COVID-19, this case underscores the importance of early diagnosis and timely antiviral treatment.

pUL34 binding near the human cytomegalovirus origin of lytic replication enhances DNA replication and viral growth

The human cytomegalovirus (HCMV) UL34 gene encodes sequence-specific DNA-binding proteins (pUL34) which are required for viral replication. Interactions of pUL34 with DNA binding sites represses transcription of two viral immune evasion genes, US3 and US9. 12 additional predicted pUL34-binding sites are present in the HCMV genome (strain AD169) with three binding sites concentrated near the HCMV origin of lytic replication (oriLyt). We used ChIP-seq analysis of pUL34-DNA interactions to confirm that pUL34 binds to the oriLyt region during infection. Mutagenesis of the UL34-binding sites in an oriLyt-containing plasmid significantly reduced viral-mediated oriLyt-dependent DNA replication. Mutagenesis of these sites in the HCMV genome reduced the replication efficiencies of the resulting viruses. Protein-protein interaction analyses demonstrated that pUL34 interacts with the viral proteins IE2, UL44, and UL84, that are essential for viral DNA replication, suggesting that pUL34-DNA interactions in the oriLyt region are involved in the DNA replication cascade.

Parameters for the Successful Management of Cytomegalovirus

Cytomegalovirus (CMV) is a major pathogen for the neonate and the transplant recipient in both of whom the incidence of the disease and its severity are increased when the donor, or mother, has a primary infection. Many individuals with recurrent infection who experience the disease do so because they are being reinfected from an exogenous source, rather than reactivating their own strain, arguing that natural immunity can reduce, but not completely control, CMV disease. Antiviral therapy is thus needed to control CMV disease. There are four major strategies for the use of drugs against CMV - prophylaxis, suppression, pre-emptive therapy and treatment; significant benefit has been shown for some of these in some groups of transplant patients. The strategies must now be compared, and patient management regimes comparing the various approaches should be considered.

Cytomegalovirus pneumonia in hematopoietic stem cell recipients

Cytomegalovirus (CMV) is a frequently encountered infection following hematopoietic cell transplantation, and tissue invasive pneumonia is a dreaded complication of the virus in this population. In this review of CMV pneumonia, we address epidemiology, pathogenesis, diagnostics, current therapy, and strategies to prevent the development of CMV. We also review emerging treatment and prevention options for this challenging disease.

Modelling cytomegalovirus replication patterns in the human host: factors important for pathogenesis

Human cytomegalovirus can cause a diverse range of diseases in different immunocompromised hosts. The pathogenic mechanisms underlying these diseases have not been fully elucidated, though the maximal viral load during infection is strongly correlated with the disease. However, concentrating on single viral load measures during infection ignores valuable information contained during the entire replication history up to the onset of disease. We use a statistical model that allows all viral load data sampled during infection to be analysed, and have applied it to four immunocompromised groups exhibiting five distinct cytomegalovirus-related diseases. The results show that for all diseases, peaks in viral load contribute less to disease progression than phases of low virus load with equal amount of viral turnover. The model accurately predicted the time of disease onset for fever, gastrointestinal disease and pneumonitis but not for hepatitis and retinitis, implying that other factors may be involved in the pathology of these diseases.

Pulmonary involvement during cytomegalovirus infection in immunosuppressed patients

Although cytomegalovirus (CMV) pulmonary involvement after solid organ transplantation is infrequently seen nowadays, CMV pneumonitis is still a potential lethal complication. Introduction of the pp65 antigenemia assay enabled early and rapid diagnosis of CMV viremia in transplant patients prior to symptoms. Also, in asymptomatic patients with CMV viremia, a decreased pulmonary diffusion capacity could be demonstrated. In this review, we discuss clinical and subclinical pulmonary involvement of CMV infection in the immunocompromised host with an emphasis on transplant recipients. The clinical course, diagnosis, therapy, prophylaxis, and pathophysiology of CMV pneumonitis are discussed.

Immune reconstitution pneumonitis following Pneumocystis carinii pneumonia in HIV-infected subjects

An HIV-infected man presented with a pneumonic illness following an episode of treated Pneumocystis carinii pneumonia (PCP). He had a rise in his CD4 count from 4 to 125 cells/microL on antiretroviral therapy prior to the onset of the second respiratory event. Bronchoalveolar lavage (BAL) revealed no pathogen, although a CD4 lymphocytosis in addition to a highly unusual population of rapidly proliferating CD8 cells was demonstrated. Following 2 weeks of steroid and anti-pneumocystis therapy, a repeat bronchoscopy demonstrated that the expression of these markers had returned to low values. This second respiratory illness, which may have arisen as a consequence of the regenerating immune response reacting to residual P. carinii antigen in the lung, is apparently not rare. When we reviewed our case notes, five further individuals were identified that had started antiretroviral therapy following an episode of PCP and subsequently developed a self-limiting pneumonitis for which no pathogen was identified on bronchoscopy.

Investigation of CMV disease in immunocompromised patients

Cytomegalovirus (CMV) is a recognised cause of morbidity and mortality in immunocompromised individuals. This review will concentrate on recent advances in the understanding of the complex interplay between the host and parasite and the pathological consequences of perturbation of the host immune system. The classic view of CMV as a slowly replicating virus is challenged by recent in vivo findings suggesting that active replication occurs dynamically in the human host, with a doubling time of approximately one day. In addition, CMV load plays a major role in viral pathogenesis, such that increased CMV replication is a significant risk factor for disease in all immunocompromised groups studied to date. These studies focus attention on understanding the virological and immunological determinants of enhanced viral replication and its pathological consequences.

Cytopathology or immunopathology? The puzzle of cytomegalovirus pneumonitis revisited

Various hypotheses have been proposed to explain why cytomegalovirus pneumonitis (CMV-P) is frequent and severe in bone marrow transplant patients while remaining rare and mild in HIV infected patients. One hypothesis suggests that CMV-P is an immunopathological condition that is common in bone marrow transplantation (BMT) under the effects of an abnormally regenerating immune system that reacts against CMV infected lung tissue. Such a hypothesis implicates CD4 T lymphocytes as one of the critical cell populations involved in immunopathology and also suggests that this process would be aborted by CD4 T cell deficiency in HIV infection. However, studies correlating the onset of CMV-P with lymphocyte reconstitution following BMT have revealed that CD4 cells are present at very low frequencies in the blood during the early period after transplantation when most cases of CMV-P occur. Furthermore, studies directly investigating bronchoalveolar lavage cell types during episodes of CMV-P in BMT patients have also failed to demonstrate significant CD4 involvement and, instead, have emphasized a predominance of natural killer (NK) cells and CD8 cells. These findings serve as the basis for questioning the validity of a CD4-driven immunopathological model of CMV-P in BMT. On the other hand, a variety of experimental and clinical observations support the protective role of CMV-specific CD3+ CD8 T lymphocytes against CMV in both immunocompetent individuals and BMT patients. In a murine BMT model, adoptive transfer of syngeneic BM cells was associated with massive increases in lung CD8 cells which resulted in the resolution rather than the exacerbation of existing CMV-P. In the light of these findings a more plausible hypothesis for CMV-P in BMT is that during the early period after transplantation adequate protective CD8 responses are absent and an uncontrolled CMV proliferation is allowed to develop. Once a critical viral load is reached a cytokine 'storm' may be triggered in the lung tissue that aggravates direct CMV-associated cytopathic effects. Likely candidates for this process would include the release of tumour necrosis factor-alpha (TNF-alpha) from alveolar macrophages stimulated by interferon-gamma (IFN-gamma) released from NK cells that are reconstituted early after BMT.

Haemolytic uraemic syndrome complicated by disseminated extraneural cryptococcosis

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Incidence of cytomegalovirus disease in the Aquitaine cohort of HIV-infected patients: a retrospective survey, 1987-1993. Groupe d'Epidémilogie Clinique du SIDA en Aquitaine (GECSA)

We estimated the incidence of the first episodes of cytomegalovirus (CMV) disease in the Aquitaine cohort of HIV-infected subjects, south-western France. Cases were retrospectively investigated using standardized definition criteria. Retinitis was confirmed by an ophthalmologist. Gastro-intestinal lesions were confirmed histologically. Encephalitis was histologically confirmed; it was considered possible if TDM or magnetic resonance imaging (MRI) and symptomatology suggested this diagnosis. Pneumopathy was probable in case of hypoxemia, interstitial X-Ray images and response to CMV treatment; it was confirmed if intranuclear inclusions were identified on biopsy or brushing specimen. In the cohort (n = 3525) followed for an average of 46 months, 158 patients had a first episode of CMV disease. The cumulative incidence was 4.5% and the incidence rate (IR) 1.2 per 100 person-years. The IR was higher for homosexuals (2.0) than for heterosexuals (1.0) and intravenous drug users (0.5). Retinitis was the most frequent site (90 cases), followed by digestive system (40), lung (three confirmed and 17 probable) and central nervous system (eight confirmed and three possible). Sixty-eight percent of the patients were at the AIDS stage when CMV disease was diagnosed, with a mean CD4 count of 42/mm3. The cumulative probability of developing CMV disease 2 years after falling below 200 CD4 lymphocytes/mm3 was 8.0%. Retinitis is by far the most common site for CMV disease. Homosexual transmission of HIV, clinical AIDS and low CD4 count are associated with the occurrence of the first episode of CMV disease.

Viral infections in human immunodeficiency virus disease

A number of the herpesviruses as well as representatives of other viral genera can produce serious opportunistic infections in persons infected with HIV. Although some, such as JC virus, HHV-6, and HHV-8, remain essentially untreatable at this time, others are readily treatable or can be retarded with chemoprophylaxis. Further therapeutic advances for some of these viral superinfections, particularly CMV, HSV, VZV, HHV-8, and human genital papillomavirus, will considerably improve the longevity and quality of life of persons with AIDS.

Viruses and other miscellaneous organisms

Pulmonary infections caused by several types of viruses and other miscellaneous organisms may cause disease in HIV infection. Evidence suggests that pulmonary conditions may result from infections of the lung by HIV itself. Other viruses, most commonly cytomegalovirus, may be primary perpetrators of pneumonitis or may contribute to diseases caused by coexisting infections. Although diagnosis and assessment of the clinical significance of these infections may be difficult, their recognition is of practical importance because potentially effective therapeutic agents are available for several of them. Miscellaneous infections such as pulmonary toxoplasmosis and pertussis are other uncommon but potentially treatable complications of HIV disease.

Pulmonary disease

This article has presented the reader with an overview of the pulmonary disorders that develop during the course of HIV disease with special emphasis on the more commonly encountered entities. This information is intended to prepare the clinician to recognize the hallmark characteristics of the various diseases as well as atypical features. Despite the advances in basic understanding of the clinicopathologic consequences of infection with HIV, a cure has not been realized. There has, however, been success in controlling some of the major pulmonary problems that adversely affect both the quality and the length of life for persons with AIDS. For most complications of HIV infection, prognosis ultimately depends not only on treatment of the specific problem, but also controlling the relentless process of progressive immunosuppression. Continued research into treatment or prevention of HIV infection itself is needed, but at present prevention, rapid diagnosis, and treatment of recognized problems remain an intermediary goal.

Detection of human cytomegalovirus DNA from allogeneic bone marrow transplant recipients with interstitial pneumonitis

Interstitial pneumonitis (IP) due to human cytomegalovirus (HCMV) infection can kill patients who receive allogeneic bone marrow transplants (BMT). However, making a definitive diagnosis of HCMV-associated IP is difficult, except in pathologically defined cases. The authors tried to detect HCMV DNA amplified by the polymerase chain reaction with nonradioactive Southern blot analysis from paraffin-embedded lung tissue. Human cytomegalovirus DNA was detected in all of ten BMT recipients with IP and all of three non-BMT recipients with histologically diagnosed HCMV IP. Clinical diagnoses indicated that three of ten allogeneic BMT recipients had HCMV IP, and they showed amplified HCMV DNA despite the lack of histologic viral inclusions. However, HCMV DNA was not detected in 11 immunosuppressed patients with non-HCMV pneumonitis who were included as controls. These observations indicate that the polymerase chain reaction and Southern blot analysis used with lung tissue is more sensitive than histologic examination, and that these tests may be applicable to transbronchial lung biopsy specimens for the early specific diagnosis of HCMV IP. Further analysis of allogeneic BMT recipients showed that four patients who died of HCMV IP fewer than 90 days after BMT had higher quantities of HCMV DNA, whereas six patients who died of HCMV IP more than 90 days after BMT showed lower quantities of HCMV DNA. THis result suggests that HCMV IP in the late phase after MBT might not be attributable to active virus replication alone but rather to the immune response involved in the graft-versus-host reaction.

The relationship between cytomegalovirus retrieved by bronchoalveolar lavage and mortality in patients with HIV

STUDY OBJECTIVE

To evaluate mortality over 6 months of patients with HIV with cytomegalovirus (CMV) cultured from bronchoalveolar lavage (BAL) compared with those without CMV and to assess the significance of CMV cytologic study, CD4+ counts, and coexistent Pneumocystis carinii pneumonia.

DESIGN

Retrospective evaluation of HIV-infected patients undergoing bronchoscopy with BAL. The 40 most recent HIV-positive patients undergoing bronchoscopy with BAL were included for each of three categories: CMV by cytologic study; CMV by culture only; and CMV absent. Patients for whom survival status at 6 months was unknown were excluded from analysis.

SETTING

University hospital, tertiary care center.

PATIENTS

Group 1 consisted of 36 patients with positive CMV culture and cytologic study and group 2 consisted of 38 patients with only a positive culture for CMV. Group 3 consisted of 40 patients with no evidence of CMV by BAL.

RESULTS

On comparison of the groups, there was no difference in 3-week survival (from date of bronchoscopy). There was a statistically significant increase in mortality in group 1 patients compared with group 3 patients at both 3 and 6 months. Between groups 2 and 3, there was a difference in mortality that approached but did not reach significance at 3 months but did at 6 months. The mortality in group 1 at 3 months = 28%, at 6 months = 47%, whereas mortality in group 2 at 3 months = 26% and at 6 months = 45%. Group 3 had a 3-month mortality of 10% and a 6-month mortality of 15%. While those patients with positive CMV cytologic study had lower mean CD4+ counts, within the group, CD4+ counts were no different between the 3-month survivors and nonsurvivors (survivors, CD4/mm3 median = 38 [0 to 141]; and nonsurvivors, CD4/mm3 median = 16 [3 to 224]). Coinfection with P carinii did not increase mortality at 3 months.

CONCLUSIONS

The CMV retrieved by BAL in HIV-infected patients was associated with significantly greater 3- and 6-month mortality. The CMV cytologic study did not predict a higher mortality and the difference in mortality between patients with and without CMV in BAL fluid was not directly attributed to lower CD4+ counts or P carinii coinfection.

The role of bronchoscopy in patients with HIV disease

Pulmonary involvement is a frequent feature of patients infected with the human immunodeficiency virus (HIV). Pneumocystis carinii pneumonia (PCP) is still the commonest AIDS defining diagnosis despite the advent of effective prophylaxis and antiretroviral treatment. Other pulmonary manifestations of AIDS, including tuberculosis, may pose a greater problem in the future. The clinical manifestations of HIV-disease are many and varied, and changing as the disease is modified by therapeutic interventions. With specific and increasingly effective treatments the need for definitive diagnosis is obvious. Fibreoptic bronchoscopy is a well established tool for the diagnosis of HIV-related pulmonary complications. This article aims to give an account on the use of bronchoscopy in a unit providing care for many HIV seropositive patients.

DNA amplification by the polymerase chain reaction to detect sub-clinical Pneumocystis carinii colonization in HIV-positive and HIV-negative male homosexuals with and without respiratory symptoms

Pneumocystis carinii colonization was studied in 90 men using the polymerase chain reaction. These comprised ten heterosexual controls; ten HIV-seronegative homosexual controls; 20 HIV-seropositive homosexuals with blood CD4 count > 400 x 10(6) l-1; 20 HIV-seropositive homosexuals with CD4 < 400 x 10(6) l-1; ten HIV-seropositive homosexuals with CD4 < 60 x 10(6) l-1 receiving PCP chemoprophylaxis; and 20 HIV-seropositive homosexuals with respiratory symptoms but without PCP. Induced sputum was obtained from all but the last group, who had bronchoalveolar lavage, and all specimens were tested for P. carinii using the polymerase chain reaction. The first four groups received no pneumocystis chemoprophylaxis, and all but the last group were asymptomatic. P. carinii colonization did not occur in the two control groups. P. carinii colonization rates were significantly different in the CD4 > 400, CD4 < 400, and CD4 < 60 groups (10%, 20%, and 40% respectively) (P < 0.025). Two patients (one each from CD4 < 400 and CD4 < 60) developed PCP 4-6 weeks after sputum induction, both had previously had high levels of P. carinii on sputum induction. Two patients from the CD4 < 400 group had high levels of P. carinii but did not develop PCP. In the symptomatic group, two subjects had low levels of P. carinii, but did not develop PCP. We have demonstrated P. carinii colonization in HIV-seropositive homosexuals in association with a low peripheral CD4 count. The polymerase chain reaction may be a useful technique for determining the need and efficacy of anti-pneumocystis chemoprophylaxis.