Organizing pneumonia as a manifestation of Pneumocystis jiroveci immune reconstitution syndrome in HIV-positive patients: report of 2 cases

Pneumocystis Pneumonia Presenting With Peripheral Predominant Consolidation and Traction Bronchiectasis

Pneumocystis jirovecii pneumonia (PCP) typically presents as a predominant ground-glass opacity (GGO) in the upper lobes. We report a case of a patient with PCP that mimicked organizing pneumonia or nonspecific interstitial pneumonia, showing peripheral predominant consolidation with traction bronchiectasis and peribronchovascular thickening in the lower lobes on high-resolution computed tomography (HRCT). Pneumocystis jirovecii was detected in bronchoalveolar lavage (BAL), and no other pathogens were isolated. After confirmation of a high plasma human immunodeficiency virus (HIV)-RNA titer and a low CD4+ cell count, the patient was diagnosed with PCP associated with HIV infection. The peripheral predominant consolidation was successfully resolved after treatment with trimethoprim-sulfamethoxazole. To the best of our knowledge, no previous case of PCP presenting with peripheral predominant consolidation, traction bronchiectasis, or peribronchovascular thickening has been reported. Physicians should consider PCP as a differential diagnosis even in cases suspected as organizing pneumonia or nonspecific interstitial pneumonia on HRCT.

Risk factors for IRIS in HIV-associated Pneumocystis-pneumonia following ART initiation

BACKGROUND

HIV-infected patients with Pneumocystis-pneumonia (PCP) may develop paradoxical immune reconstitution inflammatory syndrome (IRIS), when combination antiretroviral therapy (cART) is started early during the course of PCP-treatment (PCPT). The aim of this study was to identify risk factors and predictors for PCP-IRIS and to improve individualized patient care.

METHODS

An ICD-10 code hospital database query identified all Frankfurt HIV Cohort patients being diagnosed with PCP from January 2010 - June 2016. Patient charts were evaluated retrospectively for demographic, clinical and therapeutic (cART/PCPT) characteristics and incidence of paradoxical IRIS according to French's case definitions.

RESULTS

IRIS occurred in 12/97 patients that started cART while on PCPT (12.4%). They had a higher rate of re-hospitalization (41.7vs. 4.7%; odds ratio (OR) 14.46; p = 0.009), intensive care treatment (66.7vs. 30.6%; OR = 4.54; p = 0.018), and longer median hospitalization (48 days vs. 23; p < 0.001). A high HIV-RNA level (> 6Log₁₀/ml) before cART initiation was associated with IRIS development (41.6vs. 15.0%; OR 4.05; p = 0.042). Serum immunoglobulin G-levels (IgG) [mg/dl] were lower (894.0 vs. 1446.5; p = 0.023).

CONCLUSION

Higher hospitalization rate and morbidity parameters underscore the clinical importance of PCP-related paradoxical IRIS. A baseline viral load of > 6Log10/ml and serum IgG may help to assess individual risks for PCP-IRIS.

Organizing pneumonia secondary to Pneumocystis jirovecii infection in a kidney transplant recipient: Case report and review of literature

Organizing pneumonia (OP), previously known as bronchiolitis obliterans OP, is a diffuse parenchymal lung disease affecting the distal bronchioles, alveolar ducts, and alveolar walls. Pulmonary infections, especially bacterial and viral diseases, are known to be associated with the secondary form of OP. OP secondary to fungal infections is less common. Here, we report a case of OP associated with pneumocystis pneumonia (PCP) in a kidney transplant recipient on tacrolimus-based triple immunosuppression. The index case had developed new lung consolidation toward the end of trimethoprim-sulfamethoxazole therapy for PCP. Spontaneous clinical and radiographic resolution was seen without any increment in the dose of corticosteroids. We review the literature and present a summary of all reported cases of OP associated with PCP to date.

Understanding Pathogenesis and Care Challenges of Immune Reconstitution Inflammatory Syndrome in Fungal Infections

Immune deficiency of diverse etiology, including human immunodeficiency virus (HIV), antineoplastic agents, immunosuppressive agents used in solid organ recipients, immunomodulatory therapy, and other biologics, all promote invasive fungal infections. Subsequent voluntary or unintended immune recovery may induce an exaggerated inflammatory response defining immune reconstitution inflammatory syndrome (IRIS), which causes significant mortality and morbidity. Fungal-associated IRIS raises several diagnostic and management issues. Mostly studied with Cryptococcus, it has also been described with other major fungi implicated in human invasive fungal infections, such as Pneumocystis, Aspergillus, Candida, and Histoplasma. Furthermore, the understanding of IRIS pathogenesis remains in its infancy. This review summarizes current knowledge regarding the clinical characteristics of IRIS depending on fungal species and existing strategies to predict, prevent, and treat IRIS in this patient population, and tries to propose a common immunological background to fungal IRIS.

Immune reconstitution inflammatory syndrome in HIV-infected patients with Pneumocystis jirovecii pneumonia

INTRODUCTION

The incidence of immune reconstitution inflammatory syndrome (IRIS) in HIV-infected patients after an episode of Pneumocystis jirovecii pneumonia (PJP) seems to be lower than with other opportunistic infections. We conducted an observational study in order to determine the incidence, clinical characteristics and outcome of patients diagnosed with PJP-related IRIS.

METHODS

We conducted an observational study of HIV patients diagnosed with PJP-related IRIS from January 2000 to November 2015. We analyzed epidemiological and clinical characteristics as well as laboratory findings. We also carried out a systematic review of published cases.

RESULTS

Six cases of IRIS out of 123 (4.9%) HIV-infected patients with PJP who started ART were diagnosed. All six cases were men with a median age of 34 (IQR: 8) years. The six patients developed paradoxical IRIS. Subjects younger than 40 years old (p=0.084) and with an HIV-RNA viral load >100000 copies/ml (p=0.081) at diagnosis showed a tendency to develop IRIS. Thirty-seven published cases of PJP-related IRIS were identified. Although 51% of cases involved respiratory failure, no deaths were reported.

CONCLUSIONS

PJP-related IRIS is rare condition compared to other opportunistic infections. It can lead to a severe respiratory failure in a significant proportion of cases, although no deaths have been reported.

Complications of invasive mycoses in organ transplant recipients

INTRODUCTION

Opportunistic mycoses remain a significant complication in organ recipients. Areas covered: This review is an evidence-based presentation of current state-of-knowledge and our perspective on recent developments in the field Expert commentary: Invasive fungal infections are associated with reduced allograft and patient survival, increase in healthcare resource utilization, and newly appreciated but largely unrecognized immunologic sequelae, such as immune reconstitution syndrome. Given adverse outcomes associated with established infections, prophylaxis is a widely used strategy for the prevention of these infections. Currently available biomarkers that detect circulating fungal cell wall constituents i.e., galactomannan and 1, 3-β-D-glucan have not proven to be beneficial as screening tools for employing targeted prophylaxis or as diagnostic assays in this patient population. However, subsets of patients at risk for opportunistic fungal infections can be identified based on clinically identifiable characteristics or events. Preventive strategies targeted towards these patients are a rational approach for optimizing outcomes.

Thoracic diseases associated with HIV infection in the era of antiretroviral therapy: clinical and imaging findings

The human immunodeficiency virus (HIV) and acquired immunodeficiency syndrome (AIDS) pandemic has entered its 4th decade. Since the introduction of combination antiretroviral therapy (ART) in 1996, the number of AIDS-related deaths has plateaued worldwide. Today, owing to the effectiveness of ART, the HIV-infected population is aging and HIV infection has become a chronic illness. Non-AIDS comorbidities are increasing, and the spectrum of HIV-related thoracic diseases is evolving. In developed countries, bacterial pneumonia has become more common than Pneumocystis pneumonia. Its imaging appearance depends on the responsible organism, most commonly Streptococcus pneumoniae. Mycobacterium tuberculosis continues to be a major threat. Its imaging patterns vary depending on CD4 count. Primary lung cancer and Hodgkin lymphoma are two important non-AIDS-defining malignancies that are increasingly encountered at chest imaging. Human herpesvirus 8, also known as Kaposi sarcoma-associated herpesvirus (KSHV), is strongly linked to HIV-related diseases, including Kaposi sarcoma, multicentric Castleman disease, KSHV inflammatory cytokine syndrome, and primary effusion lymphoma. Immune reconstitution inflammatory syndrome is a direct complication of ART whose manifestations vary with the underlying disease. Given the high rate of smoking among HIV-infected patients, chronic obstructive pulmonary disease is another important cause of morbidity and mortality. A high degree of suspicion is required for the early diagnosis of pulmonary arterial hypertension and lymphocytic interstitial pneumonia, given their nonspecific manifestations. Finally, multilocular thymic cyst manifests as a cystic anterior mediastinal mass. Recognition of the clinical and radiologic manifestations of these less traditional HIV-related diseases can expedite diagnosis and treatment in the ART era.

Noninfectious pulmonary complications of human immunodeficiency virus infection

Human immunodeficiency virus type 1 (HIV-1) is the retrovirus responsible for the development of AIDS. Its profound impact on the immune system leaves the host vulnerable to a wide range of opportunistic infections not seen in individuals with a competent immune system. Pulmonary infections dominated the presentations in the early years of the epidemic, and infectious and noninfectious lung diseases remain the leading causes of morbidity and mortality in persons living with HIV despite the development of effective antiretroviral therapy. In addition to the long known immunosuppression and infection risks, it is becoming increasingly recognized that HIV promotes the risk of noninfectious pulmonary diseases through a number of different mechanisms, including direct tissue toxicity by HIV-related viral proteins and the secondary effects of coinfections. Diseases of the airways, lung parenchyma and the pulmonary vasculature, as well as pulmonary malignancies, are either more frequent in persons living with HIV or have atypical presentations. As the pulmonary infectious complications of HIV are generally well known and have been reviewed extensively, this review will focus on the breadth of noninfectious pulmonary diseases that occur in HIV-infected individuals as these may be more difficult to recognize by general medical physicians and subspecialists caring for this large and uniquely vulnerable population.

Early development of immune reconstitution inflammatory syndrome related to Pneumocystis pneumonia after antiretroviral therapy

Immune reconstitution inflammatory syndrome is a recognized complication after the initiation of combination antiretroviral therapy (cART). We report a patient who developed life-threatening pulmonary immune reconstitution inflammatory syndrome (IRIS) three days after initiation of cART. We reviewed published cases of IRIS after Pneumocystis pneumonia (PCP), in particular the time from initiation of cART to IRIS event. The median duration from the initiation of cART to the onset of IRIS was 15 days in the 33 patients reviewed. This report alerts clinicians to the rapidity of the development of pulmonary IRIS following PCP after the initiation of cART.

Evaluation of respiratory disease

The spectrum of HIV-associated pulmonary diseases is broad. Opportunistic infections, neoplasms, and noninfectious complications are all major considerations. Clinicians caring for persons infected with HIV must have a systematic approach. The approach begins with a thorough history and physical examination and often involves selected laboratory tests and a chest radiograph. Frequently, the clinical, laboratory, and chest radiographic presentation suggests a specific diagnosis or a few diagnoses, which then prompts specific diagnostic testing and treatment. This article presents an overview of the evaluation of respiratory disease in persons with HIV/AIDS.

Interstitial lung disease in HIV

A spectrum of noninfectious, nonmalignant lymphocytic infiltrative disorders, including nonspecific interstitial pneumonitis and lymphocytic interstitial pneumonitis, was frequently described in HIV-infected adults in the precombination antiretroviral therapy (ART) era. With the advent of ART, these conditions are less commonly encountered when caring for HIV-infected adults, possibly as a consequence of the effects of HIV treatment on pulmonary immunology. By contrast, reports of sarcoidosis among HIV-infected persons were uncommon in the pre-ART era, but sarcoidosis is increasingly recognized since the introduction of ART and may represent an immune reconstitution phenomenon. Other causes of interstitial pneumonitis are infrequently encountered among HIV-infected persons.

Immune reconstitution inflammatory syndrome: incidence and implications for mortality

OBJECTIVE

To describe incidence of immune reconstitution inflammatory syndrome (IRIS) and its association with mortality in a large multisite US HIV-infected cohort applying an objective, comprehensive definition.

DESIGN

We studied 2,610 patients seen during 1996-2007 who initiated or resumed highly active combination antiretroviral therapy (cART) and, during the next 6 months, demonstrated a decline in plasma HIV-RNA viral load of at least 0.5 log(10) copies/ml or an increase of at least 50% in CD4 cell count per microliter. We defined IRIS as the diagnosis of a type B or C condition [as per the Centers for Disease Control and Prevention (CDC) 1993 AIDS case definition] or any new mucocutaneous disorder during this same 6-month period.

METHODS

We assessed the incidence of IRIS and evaluated risk factors for IRIS using conditional logistic regression and for all-cause mortality using proportional hazards models.

RESULTS

We identified 370 cases of IRIS (in 276 patients). Median and nadir CD4 cell counts at cART initiation were 90 and 43 cells/μl, respectively; median viral load was 2.7 log(10) copies/ml. The most common IRIS-defining diagnoses were candidiasis (all forms), cytomegalovirus infection, disseminated Mycobacterium avium intracellulare, Pneumocystis pneumonia, varicella zoster, Kaposi's sarcoma and non-Hodgkin lymphoma. Only one case of Mycobacterium tuberculosis was observed. IRIS was independently associated with CD4 cell count less than 50 cells/μl vs. at least 200 cells/μl [odds ratio (OR) 5.0] and a viral load of at least 5.0 log(10) copies vs. less than 4.0 log(10) copies (OR 2.3). IRIS with a type B-defining or type C-defining diagnosis approximately doubled the risk for all-cause mortality.

CONCLUSION

In this large US-based HIV-infected cohort, IRIS occurred in 10.6% of patients who responded to effective ART and contributed to increased mortality.

Pulmonary manifestations of the immune reconstitution inflammatory syndrome

PURPOSE OF REVIEW

Immune reconstitution inflammatory syndrome (IRIS) is a common occurrence in HIV patients starting antiretroviral therapy (ART), and pulmonary involvement is an important feature of tuberculosis-IRIS and pneumocystis-IRIS. Pulmonologists need an awareness of the timing, presentation and treatment of pulmonary IRIS.

RECENT FINDINGS

Case definitions for tuberculosis-IRIS and cryptococcal-IRIS have been published by the International Network for the Study of HIV-associated IRIS (INSHI). A number of studies have addressed validation of clinical case definitions and the optimal time to commence ART after diagnosis of an opportunistic infection in HIV patients. The pathogenesis of IRIS is being assessed at a molecular level, increasing our understanding of mechanisms and possible targets for future preventive and therapeutic strategies.

SUMMARY

Tuberculosis-IRIS, nontuberculosis mycobacterial-IRIS and pneumocystis-IRIS occur within days to weeks of starting ART, causing substantial morbidity, but low mortality. Cryptococcal-IRIS usually occurs later in the course of ART, and may be associated with appreciable mortality. Early recognition of unmasking and paradoxical IRIS affecting the lung allows timely initiation of antimicrobial and/or immunomodulatory therapies.

Pneumocystis-associated organizing pneumonia as a manifestation of immune reconstitution inflammatory syndrome in an HIV-infected individual with a normal CD4+ T-cell count following antiretroviral therapy

We describe a rare case of Pneumocystic jirovecii-associated organizing pneumonia (PJP) in an HIV-infected individual on highly active antiretroviral therapy (HAART) with a CD4(+) T-cell count of 835 x 10(3) cells/mL and a low viral load. PJP was confirmed using transbronchial biopsies and bronchoalveolar lavage. The presentation in this patient suggests immune reconstitution inflammatory syndrome (IRIS) after institution of antiretroviral therapy (ART). This case report, however, is the first documented presentation of PJP in a patient with CD4 count greater than 300 prior to the induction of HAART who developed PJP and organizing pneumonia as a manifestation of IRIS. This suggests that there is continuing immune dysfunction in the face of re-expansion of CD4(+) T-cells and low viral load in HIV patients despite ART.