Paradoxical Reactions and the Immune Reconstitution Inflammatory Syndrome

Computed tomography imaging characteristics of paradoxical reactions in perihepatic and hepatic tuberculosis

Background

Hepatic and perihepatic tuberculosis (TB) are rare forms of extrapulmonary TB. Paradoxical reactions, characterized by the enlargement of existing lesions or the appearance of new lesions during anti-TB treatment, are uncommon in hepatic TB. This study aimed to retrospectively analyze the computed tomography (CT) imaging characteristics of paradoxical reactions in hepatic and perihepatic TB to enhance the understanding of this condition.

Methods

We conducted a retrospective review of the data of patients diagnosed with perihepatic and hepatic TB at the Kunming Third People's Hospital from January 2020 to June 2024. We selected patients with follow-up CT imaging showing paradoxical reactions, and we summarized their initial CT findings, paradoxical reaction CT manifestations, and follow-up CT presentations.

Results

The data of 37 patients with perihepatic and hepatic TB and CT follow-up imaging were collected. Of the 37 patients, 14 (37.8%) exhibited paradoxical reactions characterized by an enlargement of existing lesions or the appearance of new lesions on review. Among these 14 patients, 7 were male, 7 were female, with ages ranging from 17 to 46 years (median age: 23 years). Twelve patients had concurrent pulmonary TB, and 13 patients had other extrapulmonary TB. Thirteen patients tested positive for TB infection by interferon-gamma release assay, and eight had positive etiological results. Twelve patients showed a decrease in CD4+ T-cell counts. The time to the paradoxical reaction onset after initial diagnosis ranged from 13 to 183 days (median time: 82 days). The initial CT presentations of these 14 patients included 11 cases of perihepatic peritoneum/hepatic capsule linear or nodular thickening (capsular type), and three cases of combined perihepatic peritoneum/hepatic capsule linear or nodular thickening with hepatic parenchymal lesions (mixed type). Capsular-type paradoxical reactions manifested as new or enlarged nodules of the perihepatic peritoneum/hepatic capsule and intrahepatic lesions, with marked ring enhancement on enhanced scans. Mixed-type paradoxical reactions showed significant enlargement of perihepatic peritoneum/hepatic capsule lesions and intrahepatic lesions, with the enhanced scans showing higher ring enhancement than that in the initial presentation. Among the 12 patients with long-term follow-up data, lesion improvement began at 6 to 20 months (median time: 12 months). CT imaging showed gradual lesion size reduction, decreased ring enhancement density, an absence of ring enhancement, and lesion calcification.

Conclusions

During anti-TB treatment, perihepatic and hepatic TB patients can show paradoxical reactions, which often present as ring enhancement. After treatment, these paradoxical reaction lesions can show improvement. CT-enhanced scans have diagnostic value in the occurrence and progression of perihepatic and hepatic TB.

Perivascular enhancement pattern: Identification, diagnostic spectrum and practical approach - A pictorial review

Perivascular spaces (PVS) are fluid-filled structures that form the immediate peripheral environment of small cerebral vessels. They are a central component of the glymphatic system, which plays a crucial role in maintaining cerebral homeostasis. Their involvement in central nervous system diseases is currently a major focus of research, particularly in neuroimaging. Pathological enhancement of PVS on post-contrast MRI sequences creates a distinctive pattern due to their topography. As with other intracranial enhancement patterns, a differential diagnosis approach can be applied to perivascular enhancement (PVE). However, it is particularly challenging due to the rarity and complexity of the conditions involved. This article aims to facilitate the recognition of PVE pattern, to highlight the various causal conditions and to propose a practical diagnostic approach.

Aspergillus-related immune reconstitution inflammatory syndrome in pediatric cancer patients, clinical characteristics, imaging findings, and survival

Aspergillus-related immune reconstitution inflammatory syndrome (IRIS) is a challenge to diagnose in immunocompromised pediatric cancer patients with Invasive Pulmonary Aspergillosis (IPA). If not recognized, it can mimic disease progression and lead to overtreatment. Studies on Aspergillus-related IRIS in the pediatric population are scarce. We prospectively identified four pediatric cancer patients diagnosed with IPA who developed paradoxical worsening of pulmonary symptoms following neutrophil recovery. The clinical course, imaging findings, and response to corticosteroids were also reviewed. All patients had refractory respiratory symptoms, including cough, breathing difficulties (dyspnea), and chest pain, despite antifungal therapy. Serial imaging revealed new or enlarging pulmonary infiltrates. Symptoms improved dramatically with corticosteroids without antifungal escalation, confirming Aspergillus-related IRIS diagnosis. Aspergillus-related IRIS can occur in immunocompromised children with cancer and IPA, mimicking disease progression. Recognition is important for avoiding overtreatment. This is the first report highlighting the features of Aspergillus-related IRIS in pediatric cancer patients.

Drug-induced sarcoidosis-like reaction three months after BNT162b2 mRNA COVID-19 vaccination: A case report and review of literature

BACKGROUND

A 70-year-old man with hepatitis C virus-related recurrent hepatocellular carcinoma was admitted for further diagnosis of a 1 cm iso-hyperechoic nodule in segment (S) 5.

CASE SUMMARY

Gadolinium ethoxybenzyl diethylenetriamine pentaacetic acid-enhanced magnetic resonance imaging (EOB-MRI) revealed the nodule in S5 with a defect at the hepatobiliary phase, hyperintensity on diffusion weighted imaging (DWI) and hypointensity on apparent diffusion coefficient (ADC) map. Contrast-enhanced computed tomography revealed hypervascularity at the early phase, and delayed contrast-enhancement was observed at the late phase. Contrast-enhanced ultrasound (US) revealed incomplete defect at the late vascular phase. Inflammatory liver tumor, lymphoproliferative disease, intrahepatic cholangiocarcinoma (small duct type) and bile duct adenoma were suspected through the imaging studies. US guided biopsy, however, showed a noncaseating hepatic sarcoid-like epithelioid granuloma (HSEG), and histopathological analysis disclosed spindle shaped epithelioid cells harboring Langhans-type multinucleated giant cells. One month after admission, EOB-MRI signaled the disappearance of the defect at the hepatobiliary phase, of hyperintensity on DWI, of hypointensity on ADC map, and no stain at the early phase.

CONCLUSION

That the patient had received BNT162b2 messenger RNA (mRNA) coronavirus disease 2019 vaccination 3 mo before the occurrence of HSEG, and that its disappearance was confirmed 4 mo after mRNA vaccination suggested that the drug-induced sarcoidosis-like reaction (DISR) might be induced by the mRNA vaccination. Fortunately, rechallenge of drug-induced DISR with the third mRNA vaccination was not confirmed.

Intestinal Perforation as a Paradoxical Reaction to Tuberculosis

Paradoxical reactions (PR) to tuberculosis (TB) treatments are characterized by an initial improvement of the clinical symptoms followed by a clinical or radiological deterioration of existing TB lesions or by the development of new lesions. PR in the gastrointestinal system is a rare phenomenon. Moreover, intestinal perforation is an uncommon but potentially fatal complication of intestinal TB. We report the case of a 29-year-old female who presented with fever and abdominal pain that was associated with watery diarrhea. She was diagnosed as a case of intestinal TB. During her stay, she developed intestinal perforation following the initiation of anti-TB treatment. She was eventually managed as a case of intestinal perforation as a PR to TB.

Sterile tuberculous granuloma in a patient with XDR-TB treated with bedaquiline, pretomanid and linezolid

Drug-resistant tuberculosis (DR-TB) continues to pose a threat to the global eradication of TB. Regimens for extensively drug-resistant (XDR) TB are lengthy and poorly tolerated, often with unsuccessful outcomes. The TB Alliance Nix-TB trial investigated the safety and efficacy of a 26-week regimen of bedaquiline, pretomanid and linezolid (BPaL) in participants with XDR-TB, multidrug-resistant (MDR) TB treatment failure or intolerance. In this trial 9 out of 10 participants were cured. We describe a trial participant with XDR-TB who presented with new-onset seizures soon after BPaL treatment completion. Imaging showed a right temporal ring-enhancing lesion, and a sterile tuberculous granuloma was confirmed after a diagnostic, excisional biopsy. Learning points include management of a participant with a tuberculoma after BPaL completion, efficacy of new medications for central nervous system (CNS) TB and a review of their CNS penetration. This is the first case of pretomanid use in CNS TB.

Potential disease trigger as a therapeutic option: infliximab for paradoxical reaction in tuberculosis of the central nervous system

A 36-year-old man of central Asian origin was diagnosed with subacute disseminated tuberculosis. Initially, central nervous system involvement was suggested by an encephalopathic condition and MRI showing extensive basal and spinal meningitis. After initiation of anti-tuberculosis drugs and corticosteroid therapy, clinical and radiological deterioration of spinal damage was noted. We interpreted this in the context of a paradoxical reaction, which is suggested to be an overshooting inflammatory response after reconstitution of the immune system. Despite increased dosage of corticosteroids, a gradual worsening of gait ataxia over several weeks was noted. After administration of infliximab, the patient's condition progressively improved.

Granulomatous Sarcoidosis Mimics

Many granulomatous diseases can mimic sarcoidosis histologically and in terms of their clinical features. These mimics include infectious granulomatous diseases, granulomatous reactions to occupational and environmental exposures, granulomatous drug reactions, vasculitides and idiopathic granulomatous conditions. It is important to distinguish sarcoidosis from these mimics, as a misdiagnosis of these diseases may have serious consequences. This manuscript reviews numerous sarcoidosis mimics and describes features of these diseases that may allow them to be differentiated from sarcoidosis. Distinguishing features between sarcoidosis and its mimics requires a careful review of the medical history, symptoms, demographics, radiographic findings, histologic features, and additional laboratory data. Understanding the clinical characteristics of sarcoidosis and its mimics should lead to more accurate diagnoses and treatment of granulomatous disorders that should improve the care of these patients. As the diagnostic criteria of sarcoidosis are not standardized, it is possible that some of these sarcoidosis mimics may represent varied clinical presentations of sarcoidosis itself.

Immune Reconstitution Inflammatory Syndrome with Recurrent Paradoxical Cerebellar HIV-Associated Progressive Multifocal Leukoencephalopathy

Progressive multifocal leukoencephalopathy (PML), presenting as immune reconstitution inflammatory syndrome (IRIS), is a known complication of antiretroviral therapy (ART) in people living with HIV (PLWH). Typically preceded by ART initiation, IRIS may appear simultaneously/unmasked (PML-s-IRIS) or as a delayed/worsening/paradoxical (PML-d-IRIS) presentation of known PML disease. Primary cerebellar tropism continues to be a rare presentation, and paradoxical cerebellar involvement of PML-IRIS syndrome can be a challenge for both diagnosis and management. Steroids have been suggested as a possible therapy in severe cases but the duration of steroid therapy remain elusive. Our case is that of a 34-year-old man with newly diagnosed HIV simultaneously found to have cerebellar PML. His PML lesions however worsened after initiation of ART (PML-d-IRIS) with evidence of increased intracranial pressure. Despite initial favorable response to a short duration of steroids, he had multiple recurrence of his PML lesions after steroids were discontinued. The presence of predominant cerebellar lesions and the question of how long steroids should be provided to prevent or minimize PML recurrence is the highlight of our case. This report emphasizes the need for more controlled studies to assist clinicians in the optimal diagnosis and management of PML-IRIS in PLWH.

A Primer on the Clinical Aspects of Sarcoidosis for the Basic and Translational Scientist

The immunopathogenesis of sarcoidosis remains unclear. This failure in understanding has been clinically impactful, as it has impeded the accurate diagnosis, treatment, and prevention of this disease. Unraveling the mechanisms of sarcoidosis will require input from basic and translational scientists. In order to reach this goal, scientists must have a firm grasp of the clinical aspects of the disease, including its diagnostic criteria, the immunologic defects, clinical presentations, response to therapy, risk factors, and clinical course. This manuscript will provide an overview of the clinical aspects of sarcoidosis that are particularly relevant for the basic and translational scientist. The variable phenotypic expression of the disease will be described, which may be integral in identifying immunologic disease mechanisms that may be relevant to subgroups of sarcoidosis patients. Data concerning treatment and risk factors may yield important insights concerning germane immunologic pathways involved in the development of disease. It is hoped that this manuscript will stimulate communication between scientists and clinicians that will eventually lead to improved care of sarcoidosis patients.

Tuberculosis: a focused review for the emergency medicine clinician

INTRODUCTION

Tuberculosis (TB) is a common disease worldwide, affecting nearly one-third of the world's population. While TB has decreased in frequency in the United States, it remains an important infection to diagnose and treat.

OBJECTIVE

This narrative review discusses the evaluation and management of tuberculosis, with an emphasis on those factors most relevant for the emergency clinician.

DISCUSSION

TB is caused by Mycobacterium tuberculosis and is highly communicable through aerosolized particles. A minority of patients will develop symptomatic, primary disease. Most patients will overcome the initial infection or develop a latent infection, which can reactivate. Immunocompromised states increase the risk of primary and reactivation TB. Symptoms include fever, prolonged cough, weight loss, and hemoptysis. Initial diagnosis often includes a chest X-ray, followed by serial sputum cultures. If the patient has a normal immune system and a normal X-ray, active TB can be excluded. Newer tests, including nucleic acid amplification testing, can rapidly diagnose active TB with high sensitivity. Treatment for primary and reactivation TB differs from latent TB. Extrapulmonary forms can occur in a significant proportion of patients and involve a range of different organ systems. Patients with human immunodeficiency virus are high-risk and require specific considerations.

CONCLUSIONS

TB is a disease associated with significant morbidity and mortality. The emergency clinician must consider TB in the appropriate setting, based on history and examination. Accurate diagnosis and rapid therapy can improve patient outcomes and reduce the spread of this communicable disease.

Cutaneous tuberculosis and HIV infection at a referral centre in Rio de Janeiro, Brazil

BACKGROUND

Cutaneous tuberculosis (CTB) is a rare extrapulmonary form of tuberculosis (TB). Despite the increase in the number of cases of TB and HIV, few cases of CTB have been reported.

OBJECTIVE

To describe CTB cases among patients with HIV infection from a cohort with tuberculosis.

METHODS

We describe a series of 15 CTB and HIV cases, based on secondary data from 2000 to 2016. Diagnosis was based on isolation of Mycobacterium tuberculosis in culture or clinical response to anti-tuberculous treatment associated with positive smear or histopathologic findings from affected skin or an adjacent lymph node.

FINDINGS

Scrofuloderma was present in 12 (80%) patients and solitary gumma in three (20%) patients. One case of scrofuloderma was associated with papulonecrotic tuberculid. Seven (46.6%) patients had pulmonary TB. Diagnosis was based on culture in nine patients (60%). The median CD4 cell count was 262 cells/µL. All patients were cured at the end of treatment (median time 6 months). Three patients presented with immune reconstitution inflammatory syndrome.

CONCLUSIONS

In this study, CTB associated with HIV infection presented as localised forms or in association with pulmonary TB. In patients with HIV who have subacute and chronic skin lesions, CTB should be considered in differential diagnosis, which may represent a good opportunity for early diagnosis of active TB.

Paradoxical response in a patient with non-small cell lung cancer who received nivolumab followed by anti-Mycobacterium tuberculosis agents

Anti-programmed cell death-1 (PD-1) agents enhance the antitumor immunoresponse. A number of reports have indicated that patients with malignancies who receive anti-PD-1 agents are at risk for tuberculosis (TB) infection. In this report, we present a patient with non-small cell lung cancer who developed pulmonary tuberculosis while receiving the anti-PD-1 agent nivolumab, and who subsequently demonstrated a paradoxical response (PR) 10 days after initiation of anti-MTB treatment. We suggest that anti-PD-1 agents not only induce the development of pulmonary TB, but also development of PR after anti-MTB treatment, through upregulation of the immune response. Furthermore, based on their radiological and immunological similarity, we speculate that the schema of development of PR closely resembles that of pseudoprogression in non-small cell lung cancer patients after anti-PD-1 treatment.

Drug-Induced Sarcoidosis-Like Reactions

A drug-induced sarcoidosis-like reaction (DISR) is a systemic granulomatous reaction that is indistinguishable from sarcoidosis and occurs in a temporal relationship with initiation of an offending drug. DISRs typically improve or resolve after withdrawal of the offending drug. Four common categories of drugs that have been associated with the development of a DISR are immune checkpoint inhibitors, highly active antiretroviral therapy, interferons, and tumor necrosis factor-α antagonists. Similar to sarcoidosis, DISRs do not necessarily require treatment because they may cause no significant symptoms, quality of life impairment, or organ dysfunction. When treatment of a DISR is required, standard antisarcoidosis regimens seem to be effective. Because a DISR tends to improve or resolve when the offending drug is discontinued, this is another effective treatment for a DISR. However, the offending drug need not be discontinued if it is useful, and antigranulomatous therapy can be added. In some situations, the development of a DISR may suggest a beneficial effect of the inducing drug. Understanding the mechanisms leading to DISRs may yield important insights into the immunopathogenesis of sarcoidosis.