Pulmonary Infection with Cryptococcus neoformans in the Face of Underlying Sarcoidosis

Infectious and non-infectious precipitants of sarcoidosis

Sarcoidosis is a chronic inflammatory disease that can affect any organ in the body. Its exact cause remains unknown, but it is believed to result from a combination of genetic and environmental factors. Some potential causes of sarcoidosis include genetics, environmental triggers, immune system dysfunction, the gut microbiome, sex, and race/ethnicity. Genetic mutations are associated with protection against disease progression or an increased susceptibility to more severe disease, while exposure to certain chemicals, bacteria, viruses, or allergens can trigger the formation of immune cell congregations (granulomas) in different organs. Dysfunction of the immune system, including autoimmune reactions, may also contribute. The gut microbiome and factors such as being female or having African American, Scandinavian, Irish, or Puerto Rican heritage are additional contributors to disease outcome. Recent research has suggested that certain drugs, such as anti-Programmed Death-1 (PD-1) and antibiotics such as tuberculosis (TB) drugs, may raise the risk of developing sarcoidosis. Hormone levels, particularly higher levels of estrogen and progesterone in women, have also been linked to an increased likelihood of sarcoidosis. The diagnosis of sarcoidosis involves a comprehensive assessment that includes medical history, physical examination, laboratory tests, and imaging studies. While there is no cure for sarcoidosis, the symptoms can often be effectively managed through various treatment options. Treatment may involve the use of medications, surgical interventions, or lifestyle changes. These disparate factors suggests that sarcoidosis has multiple positive and negative exacerbants on disease severity, some of which can be ameliorated and others which cannot.

Main findings and diagnostic yield of bronchoalveolar lavage, bronchial brushing and transbronchial biopsy in HIV-positive patients

Bronchoalveolar lavage, bronchial brushing and transbronchial biopsy are of fundamental importance in the diagnosis of pathologies affecting the lungs of immunosuppressed patients, especially those infected with HIV. This was a descriptive and retrospective study, in which the results of bronchoalveolar lavages, bronchial brushings and transbronchial biopsies of HIV-positive patients attended at the Clinical Hospital of the Federal University of Triangulo Mineiro from 1999 to 2015 were reviewed to determine the most frequent findings in these patients, to evaluate the diagnostic accuracy of these procedures and to correlate bronchoscopy results with clinical and radiological findings. Serological tests for HIV were confirmed and cases with negative or unverified serology were excluded. Medical records were reviewed for correlation with clinical and radiological findings. A total of 1,423 patients with a mean age of 50 years were initially selected; 727 cases had no serology for HIV; 696 had serology for HIV and 64 were positive. Of these, 47 were men, aged 24 to 84 years, and 17 women, aged 31 to 69 years. Biopsies and cytological tests were positive in 20 (31.25%) of the 64 patients and the most frequent diagnosis was pneumocystosis, found in 8 cases (12.5%). Of the 20 bronchofibroscopy-positive patients, only 2 did not show agreement between histopathological and clinical-radiological diagnoses. The analysis of the cytological tests and biopsy specimens obtained by bronchofibroscopy seems to be valuable for the etiological diagnosis of pulmonary infections in HIV- positive patients; however, negative results do not always exclude the diagnosis. In these cases, clinical symptoms and imaging findings may help to guide the best therapy.

[Cryptococcal infection and sarcoidosis: a coincidence?]

INTRODUCTION

We report a case of cryptococcal infection that underwent in a patient with a medical history of asymptomatic sarcoidosis. This finding seems to be not incidental.

CASE REPORT

A 35-years-old female was referred to hospital for a community-acquired pneumonia with pleural involvement. A physical examination showed a pleural syndrome. Chest imaging showed a parenchymal involvement with pleural effusion and numerous mediastinal nodes. Fiberoptic bronchoscopy revealed an obstruction of the right apical bronchus of the lower lobe. Biopsies and bronchoalveolar lavage confirmed a cryptococcal infection. The disease was considered as disseminated with a urinary and neurologic involvement. The outcome was fair under prolonged antifungal therapy.

CONCLUSIONS

Cryptococcal infection is generally associated with immunosuppression. We suggest that sarcoidosis, although non symptomatic, may be a condition that promote the onset of cryptococcal infection. Even rare, cryptococcal infection is the most frequent opportunistic infection recorded with sarcoidosis patients. Histologic similarities between sarcoidosis and cryptococcal infection and the role of the macrophages which phagocyte the Cryptococcus neoformans are one of the hypothesis to assess these pathologic findings. A register is warranted to recover all opportunistic infection related to sarcoidosis in order to better understand the pathogeny.

Elongated TCR alpha chain CDR3 favors an altered CD4 cytokine profile

Background

CD4 T lymphocyte activation requires T cell receptor (TCR) engagement by peptide/MHC (major histocompatibility complex) (pMHC). The TCR complementarity-determining region 3 (CDR3) contains variable α and β loops critical for pMHC recognition. During any immune response, tuning of TCR usage through progressive clonal selection occurs. Th1 and Th2 cells operate at different avidities for activation and display distinct transcriptional programs, although polarization may be plastic, influenced by pathogens and cytokines. We therefore hypothesized that CDR3αβ sequence features may intrinsically influence CD4 phenotype during progression of a response.

Results

We show that CD4 polarization involves distinct CDR3α usage: Th1 and Th17 cells favored short TCR CDR3α sequences of 12 and 11 amino acids, respectively, while Th2 cells favored elongated CDR3α loops of 14 amino acids, with lower predicted affinity. The dominant Th2- and Th1-derived TCRα sequences with14 amino acid CDR3 loops and 12 amino acid CDR3 loops, respectively, were expressed in TCR transgenics. The functional impact of these TCRα transgenes was assessed after in vivo priming with a peptide/adjuvant. The short, Th1-derived receptor transgenic T cell lines made IFNγ, but not IL-4, 5 or 13, while the elongated, Th2-derived receptor transgenic T cell lines made little or no IFNγ, but increased IL-4, 5 and 13 with progressive re-stimulations, mirrored by GATA-3 up-regulation. T cells from primed Th2 TCRα transgenics selected dominant TCR Vβ expansions, allowing us to generate TCRαβ transgenics carrying the favored, Th2-derived receptor heterodimer. Primed T cells from TCRαβ transgenics made little or no IL-17 or IFNγ, but favored IL-9 after priming with Complete Freund’s adjuvant and IL-4, 5, 9, 10 and 13 after priming with incomplete Freund’s. In tetramer-binding studies, this transgenic receptor showed low binding avidity for pMHC and polarized T cell lines show TCR avidity for Th17 > Th1 > Th2. While transgenic expression of a Th2-derived, ‘elongated’ TCR-CDR3α and the TCRαβ pair, clearly generated a program shifted away from Th1 immunity and with low binding avidity, cytokine-skewing could be over-ridden by altering peptide challenge dose.

Conclusion

We propose that selection from responding clones with distinctive TCRs on the basis of functional avidity can direct a preference away from Th1 effector responses, favoring Th2 cytokines.

Cryptococcosis in sarcoidosis: cryptOsarc, a comparative study of 18 cases

AIM

To describe the main characteristics and the treatment of cryptococcosis in patients with sarcoidosis.

DESIGN

Multicenter study including all patients notified at the French National Reference Center for Invasive Mycoses and Antifungals.

METHODS

Retrospective chart review. Each case was compared with two controls without opportunistic infections.

RESULTS

Eighteen cases of cryptococcosis complicating sarcoidosis were analyzed (13 men and 5 women). With 2749 cases of cryptococcosis registered in France during the inclusion period of this study, sarcoidosis accounted for 0.6% of all the cryptococcosis patients and for 2.9% of the cryptococcosis HIV-seronegative patients. Cryptococcosis and sarcoidosis were diagnosed concomitantly in four cases; while sarcoidosis was previously known in 14/18 patients, including 12 patients (67%) treated with steroids. The median rate of CD4 T cells was 145 per mm(3) (range: 55-1300) and not related to steroid treatment. Thirteen patients had cryptococcal meningitis (72%), three osteoarticular (17%) and four disseminated infections (22%). Sixteen patients (89%) presented a complete response to antifungal therapy. After a mean follow-up of 6 years, no death was attributable to cryptococcosis. Extra-thoracic sarcoidosis and steroids were independent risk factors of cryptococcosis in a logistic regression model adjusted with the sex of the patients.

CONCLUSIONS

Cryptococcosis is a significant opportunistic infection during extra-thoracic sarcoidosis, which occurs in one-third of the cases in patients without any treatment; it is not associated to severe CD4 lymphocytopenia and has a good prognosis.