Primary Toxoplasma gondii infection-associated with hemophagocytic syndrome in a man with HIV infection: a case report

Etiological stratification and prognostic assessment of haemophagocytic lymphohistiocytosis by machine learning on onco-mNGS data and clinical data

Introduction

Hemophagocytic lymphohistiocytosis (HLH) is a rare, complicated and life threatening hyperinflammatory syndrome that maybe triggered by various infectious agents, malignancies and rheumatologic disorders. Early diagnosis and identification of the cause is essential to initiate appropriate treatment and improve the quality of life and survival of patients. The recently developed Onco-mNGS technology can be successfully used for simultaneous detection of infections and tumors.

Methods

In the present study, 92 patients with clinically confirmed HLH were etiologically subtyped for infection, tumor and autoimmunity based on CNV and microbial data generated by Onco-mNGS technology, and a predictive model was developed and validated for the differential diagnosis of the underlying disease leading to secondary HLH. Furthermore, the treatment outcomes of patients with HLH triggered by EBV infection and non-EBV infection were evaluated, respectively.

Results

The current study demonstrated that the novel Onco-mNGS can identify the infection and malignancy- related triggers among patients with secondary HLH. A random forest classification model based on CNV profile, infectious pathogen spectrum and blood microbial community was developed to better identify the different HLH subtypes and determine the underlying triggers. The prognosis for treatment of HLH patients is not only associated with CNV, but also with the presence of pathogens and non- pathogens in peripheral blood. Higher CNV burden along with frequent deletions on chromosome 19, higher pathogen burden and lower non-pathogenic microbes were prognosis factors that significantly related with unfavorable treatment outcomes.

Discussion

Our study provided comprehensive knowledge in the triggers and prognostic predictors of patients with secondary HLH, which may help early diagnosis and appropriate targeted therapy, thus improving the survival and prognosis of the patients.

Microbiomes Detected by Bronchoalveolar Lavage Fluid Metagenomic Next-Generation Sequencing among HIV-Infected and Uninfected Patients with Pulmonary Infection

Comparison of lung microbiomes between HIV-infected and uninfected patients with pulmonary infection by metagenomic next-generation sequencing (mNGS) has not been described in China. The lung microbiomes detected in bronchoalveolar fluid (BALF) by mNGS among HIV-infected and uninfected patients with pulmonary infection were reviewed in the First Hospital of Changsha between January 2019 and June 2022. In total, 476 HIV-infected and 280 uninfected patients with pulmonary infection were enrolled. Compared with HIV-uninfected patients, the proportions of Mycobacterium (P = 0.011), fungi (P < 0.001), and viruses (P < 0.001) were significantly higher in HIV-infected patients. The higher positive rate of Mycobacterium tuberculosis (MTB; P = 0.018), higher positive rates of Pneumocystis jirovecii and Talaromyces marneffei (all P < 0.001), and higher positive rate of cytomegalovirus (P < 0.001) contributed to the increased proportions of Mycobacterium, fungi, and viruses among HIV-infected patients, respectively. The constituent ratios of Streptococcus pneumoniae (P = 0.007) and Tropheryma whipplei (P = 0.002) in the bacteria spectrum were significantly higher, while the constituent ratio of Klebsiella pneumoniae (P = 0.005) was significantly lower in HIV-infected patients than in HIV-uninfected patients. Compared with HIV-uninfected patients, the constituent ratios of P. jirovecii and T. marneffei (all P < 0.001) in the fungal spectrum were significantly higher, while the constituent ratios of Candida and Aspergillus (all P < 0.001) were significantly lower in HIV-infected patients. In comparison to HIV-infected patients without antiretroviral therapy (ART), the proportions of T. whipplei (P = 0.001), MTB (P = 0.024), P. jirovecii (P < 0.001), T. marneffei (P < 0.001), and cytomegalovirus (P = 0.008) were significantly lower in HIV-infected patients on ART. Significant differences in lung microbiomes exist between HIV-infected and uninfected patients with pulmonary infection, and ART influences the lung microbiomes among HIV-infected patients with pulmonary infection. IMPORTANCE A better understanding of lung microorganisms is conducive to early diagnosis and treatment and will improve the prognosis of HIV-infected patients with pulmonary infection. Currently, few studies have systematically described the spectrum of pulmonary infection among HIV-infected patients. This study is the first to provide comprehensive information on the lung microbiomes of HIV-infected patients with pulmonary infection (as assessed by more sensitive metagenomic next-generation sequencing of bronchoalveolar fluid) compared with those from HIV-uninfected patients, which could provide a reference for the etiology of pulmonary infection among HIV-infected patients.

Toxoplasma Lymphadenopathy: A Comparative Diagnostic Assessment of Clinical, Serological and Histopathological Findings

Introduction

Toxoplasma Gondii (TG) is a zoonotic protozoan with extensive symptomatology. Toxoplasmic lymphadenopathy is considered an affirmative sign and is proved by a biopsy of the enlarged nodule. This study was conducted to compare the clinical, serological, and histopathological findings for the diagnosis of toxoplasmic lymphadenopathy.

Materials and Methods

This study involved biopsy examinations from twelve cases with TG lymphadenopathy. ELISA serological tests were performed for TG specific IgM and IgG immunoglobulins. PCR was done to ratify the results obtained by ELISA.

Results

The ages of the patients ranged from 15 to 48 years (mean=27.8). Most of the cases are male n=8(66.7%), while female n=4(33.3%). The asthenia was not only the most frequent clinical presentation (83.3%), but it also last longer. All cases had a positive biopsy. Eight (67.7%) cases revealed seropositivity. Two of them had positive PCR in those who were positive IgM, suggesting that the infection was acute. Six (50%) cases revealed positive IgG tests, while those with negative serology were 4(33.3%). The site of lymph nodes involvement had been assessed and mostly cervical (91.6%).

Conclusion

The histopathological results yielded 100% positive findings, thus biopsy was very important in the diagnosis and differential diagnosis of lymph nodes enlargement. The chronic phase of toxoplasmosis does not show the protozoa in the blood causing an absent DNA band for amplification of the PCR cycles, which could explain the lack of bands particular for TG. A negative serological test does not exclude toxoplasmic lymphadenitis, especially in immune-compromised patients.

Advances and Challenges in Diagnostics of Toxoplasmosis in HIV-Infected Patients

Toxoplasma gondii is a worldwide distributed protozoan parasite. This apicomplexan parasite infects one-third of the population worldwide, causing toxoplasmosis, considered one of the neglected parasitic infections. In healthy humans, most infections are asymptomatic. However, in immunocompromised patients, the course of the disease can be life-threatening. Human immunodeficiency virus (HIV)-infected patients have a very high burden of Toxoplasma gondii co-infection. Thus, it is essential to use modern, sensitive, and specific methods to properly monitor the course of toxoplasmosis in immunodeficient patients.

Tuberculosis infection related hemophagocytic lymphohistiocytosis diagnosed in patient with GZMB mutation: A case report and literature review

BACKGROUND

Secondary hemophagocytic lymphohistiocytosis (HLH) is a life-threatening syndrome associated with infections, tumors and connective tissue disease. However rapid identification of the underlying infectious cause of HLH is challenging because traditional etiological diagnostics are time-consuming and sometimes fail to identify the pathogens. Metagenomic next-generation sequencing (mNGS) may be a potential optimal solution, which may help improve the clinical diagnosis of underlying infections in hematological diseases.

CASE PRESENTATION

A 28-year-old man presented with a 2-month history of intermittent fever and cytopenia. The HLH was diagnosed based on the manifestations of fever, splenomegaly, anemia, thrombocytopenia, hyperferritinemia, hyperglyceridemia, and elevated IL-2R levels. High-through-put sequencing analysis detected a GZMB mutation. While the initial detection of cultures and smears of tuberculosis was negative, TB infection was eventually identified by mNGS of blood sample. The symptoms rapidly abated during the initial administration of TB.

CONCLUSION

The present case proposed that mNGS might be an effective diagnostic tool for diagnosing rare infectious cause of secondary HLH. GZMB mutation was first discovered to be present in secondary HLH.