When to suspect an immune deficiency in adults?

Immune deficiencies in adults are quite common conditions in medical practice. However, they present with different clinical phenotypes, whether primary or secondary, which makes their diagnosis more tedious, hence diagnostic and management delays. Through this update, we will review the most common immune deficiencies, their presentations and features. This update's main aim was to propose to the practitioner a structured clinical reasoning and approach, in order to suspect an immune deficiency and initiate a guided exploration. It will also be easier for him to know when a referral to the specialist is necessary.

More than a 'Hundred Days War': Persistent SARS-CoV-2 infection in a patient with ANCA-associated vasculitis

BACKGROUND

Few reports exist on the characteristics and outcomes of persistent severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection in immunocompromised hosts.

METHODS

A 49-year-old patient with granulomatosis with polyangiitis (GPA) and a renal transplant experienced multiple hospitalizations for coronavirus disease 2019 (COVID-19) pneumonia and relapses between October 2020 and February 2021. Careful chart review of medical history, hospitalizations, and microbiological testing including SARS-CoV-2 cycle threshold values, therapies, and imaging was undertaken. SARS-CoV-2 genome sequencing was performed in five viral samples to distinguish persistent infection from re-infection with a different strain.

RESULTS

Sequencing confirmed that all samples tested were from the same viral lineage, indicating a long-term, persistent infection rather than re-infection with a new strain. The patient ultimately stabilized after two courses of remdesivir plus dexamethasone, replacement intravenous immunoglobulin, and bamlanivimab. Rituximab maintenance therapy for vasculitis remains on hold.

CONCLUSIONS

SARS-CoV-2 may persist for several months in immunocompromised hosts and may go unrecognized as an ongoing active infection. More studies are needed to determine how to optimize COVID-19 treatment in this vulnerable population.

[EBV and immunodeficiency]

Epstein-Barr virus (EBV), discovered in 1964, is a double-stranded DNA virus belonging to the Herpesviridae family. EBV has a lymphoid tropism with transforming capacities using different oncogenic viral proteins. This virus has two replication cycles: a lytic cycle mainly occuring during primary infection and a latent cycle allowing viral persistence into host memory B cells. More than 90% of adults are seropositive for EBV worldwide, with a past history of asymptomatic or mild primary infection. EBV infection can sometimes cause life-threatening complications such as hemophagocytic lymphohistiocytosis, and lead to the development of lymphoproliferative disorders or cancers. Risk factors associated with these phenotypes have been recently described through the study of monogenic primary immune deficiencies with EBV susceptibility. We here review the virological and immunological aspects of EBV infection and EBV-related complications with an overview of current available treatments.

[A rare but increasing aetiology of febrile dyspnea in the elderly]

Pneumocystis jirovecii pneumonia (PJP) is an opportunistic infectious disease well described in patients living with HIV (PLHIV) but that can occur in other immunosuppressed patients. Currently, its incidence decreases in PLHIV but increases in non-HIV immunosuppressed patients, particularly in case of hematological diseases. Thus, in elderly, the diagnosis of PJP should be evoked in case of subacute pneumonia rapidly evolving to an acute respiratory distress, with or without interstitial pneumonia at chest radiography, and a context of immunosuppression.

[Aspergillus-related respiratory conditions and COPD: Diagnostic challenges]

INTRODUCTION

The relations between chronic obstructive pulmonary disease (COPD) and respiratory diseases due to Aspergillus spp. are not well understood.

METHODS

We analysed a retrospective series of patients hospitalized with a diagnosis of COPD and respiratory disease due to Aspergillus. Patients were identified between 2010 and 2015 from the medico-administrative database of Cochin hospital, Paris. Historical, clinical, biological, microbiological and imaging data were collected and described. Diagnoses were reclassified based on reference definitions and classifications from the literature. Patients were classified according to the type of Aspergillus-related diseases and risk factors were described.

RESULTS

Forty patients were identified. Classifiable Aspergillus-related respiratory conditions were confirmed in 26 of them including 12 allergic bronchopulmonary aspergillosis (ABPA), 8 chronic pulmonary aspergillosis (CPA), 1 invasive pulmonary aspergillosis (IPA) and 3 diagnostic associations ABPA/CPA. Other respiratory comorbidities were present in all cases of CPA and immunodepression was recorded for semi-invasive and invasive forms. Finally, 16 patients could not be classified, among whom Aspergillus related lung disease was considered as likely in one-half.

CONCLUSION

The complexity of the diagnosis of pulmonary aspergillosis is related to its multiple types with sometimes unclear distinctions. Any type of pulmonary aspergillosis can be observed in patients with COPD, depending on associated risks factors. It would be helpful to establish specific classifications adapted to patients with COPD. This will require larger, prospective, multicentre studies.

[A case of disseminated cryptococcosis complicating treatment of pemphigus vulgaris with prednisone and azathioprime]

L'infection à cryptocoque est une complication redoutable chez les patients traités par immunosuppresseurs et dont l’évolution peut être rapidement fatal en cas de retard diagnostic. Nous rapportons le cas d'une patiente âgée de 70 ans, ayant des antécédents de pemphigus vulgaire traité par prednisone et azathioprime et admise dans le service de médecine Interne pour des nodules sous cutanés atypiques. Le diagnostic retenu était celui d'une cryptococcose disséminée. L’évolution était rapidement fatale malgré le traitement antifongique.

Cellular immune status of coronavirus-infected neonatal calves

A preliminary study was conducted to determine the cellular immune status of neonatal, colostrum-deprived calves following inoculation with either attenuated or virulent bovine coronavirus (BCV). Uninfected calves served as controls. To determine the intestinal and systemic cellular immune status, we performed MHC-restricted cytotoxic lymphocyte (CTL) assay on mesenteric lymphocytes, enumerated T cell subsets in peripheral blood lymphocytes, and examined histopathological alterations in mesenteric lymph nodes and gut-associated lymphoid tissue. Target cells for the CTL assay were autologous testicular cells and effector cells were mesenteric lymphocytes from calves infected with BCV. No appreciable specific lysis was observed in any group of calves indicating the absence of demonstrable CTL responses. The TC/TS population was severely depressed in the calf inoculated with the virulent virus but not in those inoculated with either the attenuated virus or placebo. The mesenteric lymph nodes and Peyer's patches of calves inoculated with the virulent virus showed severe depletion of lymphocytes. These calves developed intestinal antibody responses in the acute phase of infection (1 week after infection) but were immunosuppressed in the later stage of infection.