Disseminated Mycobacterium abscessus subsp. massiliense infection in a Good's syndrome patient negative for human immunodeficiency virus and anti-interferon-γ autoantibody: a case report

Thymoma with immunodeficiency, combined diffuse panbronchiolitis, and latent autoimmune diabetes in adults- case report and systematic review

Thymoma with Immunodeficiency (Good's Syndrome, GS) is a rare association between thymoma and immunodeficiency, first described over 60 years ago. Patients with GS typically present with thymomas, reduced or absent B cells in the peripheral blood, hypogammaglobulinemia, and defects in cell-mediated immunity. We report the case of a 67-year-old woman diagnosed with GS following the development of a progressive, severe, refractory pulmonary infection and diffuse panbronchiolitis (DPB). She also had diabetes, characterized by anti-glutamic acid decarboxylase antibody positivity, leading to a diagnosis of latent autoimmune diabetes in adults (LADA). A thorough review of existing literature revealed that GS is often confirmed after multiple episodes of opportunistic infections or autoimmune diseases post-thymoma surgery. Due to their immunodeficiency, GS patients frequently suffer from recurrent infections over extended periods, and some succumb to severe infections. Regular immunoglobulin infusions may be effective in treating GS.

Disseminated Mycobacterium abscessus infection with osteoarticular manifestations as an important differential diagnosis of inflammatory arthritis: A case report and literature review

This case report describes a 52-year-old immunocompromised man diagnosed with disseminated Mycobacterium abscessus complex (MABC) infection. The patient had a history of malignant lymphoma and presented with fever and polyarthritis that lasted 3 weeks. Upon initial evaluation, blood and synovial fluid cultures from the swollen joints were negative. Reactive arthritis or rheumatoid arthritis was suspected as the cause of inflammatory synovitis in multiple joints. Administration of prednisolone followed by an interleukin-6 inhibitor improved the fever, but polyarthritis persisted, and destruction of the left hip joint was observed. Two months later, M. abscessus was detected in a blood culture and right shoulder joint synovium, leading to a final diagnosis of disseminated MABC infection. The joint symptoms resolved with combined antimicrobial therapy using amikacin, azithromycin, and imipenem/cilastatin. To date, 12 cases of disseminated MABC infection with osteoarticular manifestations have been reported. A total of 13 cases, including the present case, were reviewed. Seven patients had bone involvements, five had joint involvement, and the remaining one had bursa involvement. All the cases with joint involvement, except for our case, presented with monoarthritis. MABC infection is diagnosed based on the demonstration of MABC itself. Clinicians should keep disseminated MABC infection in mind as a possible cause of persistent arthritis. As demonstrated in our case, multiple replicate cultures of blood or specimens from the affected sites may be needed to detect it.

SARS-CoV-2 T Cell Response in Severe and Fatal COVID-19 in Primary Antibody Deficiency Patients Without Specific Humoral Immunity

Morbidity and mortality of COVID-19 is increased in patients with inborn errors of immunity (IEI). Age and comorbidities and also impaired type I interferon immunity were identified as relevant risk factors. In patients with primary antibody deficiency (PAD) and lack of specific humoral immune response to SARS-CoV-2, clinical disease outcome is very heterogeneous. Despite extensive clinical reports, underlying immunological mechanisms are poorly characterized and levels of T cellular and innate immunity in severe cases remain to be determined. In the present study, we report clinical and immunological findings of 5 PAD patients with severe and fatal COVID-19 and undetectable specific humoral immune response to SARS-CoV-2. Reactive T cells to SARS-CoV-2 spike (S) and nucleocapsid (NCAP) peptide pools were analyzed comparatively by flow cytometry in PAD patients, convalescents and naïve healthy individuals. All examined PAD patients developed a robust T cell response. The presence of polyfunctional cytokine producing activated CD4+ T cells indicates a memory-like phenotype. An analysis of innate immune response revealed elevated CD169 (SIGLEC1) expression on monocytes, a surrogate marker for type I interferon response, and presence of type I interferon autoantibodies was excluded. SARS-CoV-2 RNA was detectable in peripheral blood in three severe COVID-19 patients with PAD. Viral clearance in blood was observed after treatment with COVID-19 convalescent plasma/monoclonal antibody administration. However, prolonged mucosal viral shedding was observed in all patients (median 67 days) with maximum duration of 127 days. PAD patients without specific humoral SARS-CoV-2 immunity may suffer from severe or fatal COVID-19 despite robust T cell and normal innate immune response. Intensified monitoring for long persistence of SARS-CoV-2 viral shedding and (prophylactic) convalescent plasma/specific IgG as beneficial treatment option in severe cases with RNAemia should be considered in seronegative PAD patients.

Severe Pulmonary Mycobacterium abscessus Cases Due to Co-Infection with Other Microorganisms Well Treated by Clarithromycin and Sitafloxacin in Japan

Background

Mycobacterium abscessus frequently causes severe infections, yet its pathophysiological features and treatment regimens have not been established.

Case Report

We present five cases of severe pneumonia due to Mycobacterium abscessus infection in Japan. All cases were diabetic patients, with possible acceleration to pneumonia due to co-infection with other microorganisms. However, following a short period of hospitalization and combination therapy with intravenous imipenem/cilastatin and amikacin, all the cases were successfully treated as outpatients with oral clarithromycin and sitafloxacin.

Conclusion

M. abscessus infections can become severe in the presence of diabetes mellitus and co-infection with other chronic infectious organisms. Sitafloxacin might be a key drug in the treatment of M. abscessus infection in future.

When the Good Syndrome Goes Bad: A Systematic Literature Review

Background

Good syndrome is a rare adult-onset immunodeficiency characterized by thymoma and hypogammaglobulinemia. Its clinical manifestations are highly heterogeneous, ranging from various infections to autoimmunity.

Objective

This study was to summarize patient characteristics, identify prognostic factors and define clinical subgroups of Good syndrome.

Methods

A systematic literature review was conducted to include patients with Good syndrome identified in PubMed, Embase and Cochrane databases between January 2010 and November 2020. Logistic and Cox regressions were used to identify prognostic factors impacting outcomes. Clinical subgroups were defined by multiple correspondence analysis and unsupervised hierarchical clustering. A decision tree was constructed to characterize the subgroup placement of cases.

Results

Of 162 patients included in the current study, the median age at diagnosis was 58 years and 51% were male. Type AB was the most common histological subtype of thymoma, and infections as well as concurrent autoimmune disorders were identified in 92.6% and 51.2% patients, respectively. Laboratory workup showed typical findings of combined immunodeficiency. Thymoma status (odds ratio [OR] 4.157, confidence interval [CI] 1.219-14.177, p = 0.023), infections related to cellular immunity defects (OR 3.324, 95% CI 1.100-10.046, p = 0.033), infections of sinopulmonary tract (OR 14.351, 95% CI 2.525-81.576, p = 0.003), central nerve system (OR 6.403, 95% CI 1.205-34.027, p = 0.029) as well as bloodstream (OR 6.917, 95% CI 1.519-31.505, p = 0.012) were independent prognostic factors. The 10-year overall survival was 53.7%. Cluster analysis revealed three clinical subgroups with distinct characteristics and prognosis (cluster 1, infections related to cellular immunity defects; cluster 2, infections related to other immunity defects; cluster 3, infections related to humoral and phagocytic immunity defects). A decision tree using infection types (related to humoral and cellular immunity defects) could place patients into corresponding clusters with an overall correct prediction of 72.2%.

Conclusions

Infection type and site were the main prognostic factors impacting survival of patients with Good syndrome. We identified three subgroups within Good syndrome associated with distinct clinical features, which may facilitate the study of underlying pathogenesis as well as development of targeted therapy.