Mycological Profile of Sputum of HIV Positive Patients with Lower Respiratory Tract Infection and its Correlation with CD4+ T Lymphocyte Count

Establishing immune scoring model based on combination of the number, function, and phenotype of lymphocytes

Background: Quantitatively assessing host immunity remains a challenge in clinical practice.

Results: Most parameters in lymphocyte number, function and phenotype were correlated with age. The reference ranges of these parameters were established in four age groups (children, adolescents, adults, and elders). The numbers of CD4⁺ T cells, CD8⁺ T cells, B cells, but not NK cells, were negatively correlated with age. However, the function of CD4⁺ T cells, CD8⁺ T cells and NK cells was positively correlated with age. The expression of CD28 on T cells gradually decreased with increasing age and was negatively correlated with their function. An opposite phenomenon was observed in the expressions of HLA-DR and CD45RO on T cells. An immune scoring model was established by using 8 parameters (CD4⁺ T cell number × function, CD28⁺CD4⁺ T cell number, HLA-DR⁺CD4⁺ T cell number, CD45RO⁺CD4⁺ T cell number, CD8⁺ T cell number × function, CD28⁺CD8⁺ T cell number, HLA-DR⁺CD8⁺ T cell number, NK cell number × function) from the results of lymphocyte number, function, and phenotype. This immune scoring model showed sensitivities of 70% and 71.4% in determining hyper-immune and hypo-immune status, respectively.

Conclusions: An immune scoring model based on combination of lymphocyte number, function, and phenotype shows potential value in quantitatively assessing host immunity.

Methods: 261 healthy individuals aged 1 to 82 years were recruited from Tongji Hospital. The number, function, and phenotype of CD4⁺ T cells, CD8⁺ T cells and NK cells were simultaneously determined.

Opportunistic Respiratory Infections in HIV Patients Attending Sukraraj Tropical and Infectious Diseases Hospital in Kathmandu, Nepal

Introduction

Opportunistic bacterial and fungal infections are the major cause of morbidity and mortality among immune suppressed HIV-positive patients. The main objective of this study was to determine bacterial and fungal organisms causing respiratory infections and their susceptibility to commonly prescribed antimicrobials among HIV patients attending a tertiary infectious disease hospital in Kathmandu.

Methods

Sputum samples were collected from the HIV-positive patients attending Sukraraj Tropical and Infectious Disease Hospital (STIDH) from August 2017 to March 2018. A total of 100 sputum samples were cultured on conventional bacterial and fungal culture media. Bacterial and fungal isolates were identified based on their colony characteristics, microscopic morphology and various biochemical tests. Antibiotic susceptibility test (AST) of bacterial isolates was performed by modified Kirby Bauer disc diffusion method.

Results

Out of 100 sputum samples cultured, 24% (n=24) showed bacterial growth, 42% (n=42) showed fungal growth and 10% (n=10) had both bacterial and fungal growth. Among bacteria, 91.6% (n=22) were monomicrobial and 8.4% (n=2) were polymicrobial in growth, of which, Klebsiella pneumoniae (37.5%) were predominant isolates, followed by Pseudomonas aeruginosa (29.2%), and Escherichia coli (16.7%). The antibiotic susceptibility test (AST) showed 68% (17/25) of bacterial isolates were multi-drug resistant (MDR) and among them 41.2% (7/17) were found to be extended spectrum β lactamase (ESBL) producers. Fungal growth was observed in 42% of samples (42/100). A total of six different species of Candida and four different genera of molds were identified. On species differentiation, Candida albicans (20%) were followed by Candida parapsilosis (4%), and Candida dubliniensis (3%); and various molds were Aspergillus fumigatus (4%), Aspergillus flavus (2%), and Penicillium species (5%). CD4 count was inversely associated with bacterial and fungal infections. Fifty percent of the patients with the fungal infections had a CD4 count below 200. No fungal organisms were isolated from HIV-positive patients under antifungal drug treatment.

Conclusion

HIV-positive patients with a CD4 count less than 200 cells/µL are more vulnerable to opportunistic infections of bacterial and fungal origin. Early isolation, identification and appropriate treatment can reduce mortality due to co-infections. Routine screening of opportunistic pathogens is critical to contain the disease progression.

Phenotypic profile of pulmonary aspergillosis and associated cellular immunity among people living with human immunodeficiency virus in Maiduguri, Nigeria

Objective:

Aspergillus causes many forms of pulmonary infectious diseases ranging from colonization (noninvasive) to invasive aspergillosis. This largely depends on the underlying host's lung health and immune status. Pulmonary aspergillosis (PA), especially the invasive form, occurs as opportunistic to human immunodeficiency virus (HIV) as a result of cluster of differentiation (CD)4+ lymphopenia. The majority of patients with comorbid HIV and aspergillosis go undiagnosed. This study aimed to isolate, identify the etiologies, and determine the prevalence of PA among HIV-infected persons with a productive cough (at least <2 weeks) at the HIV Clinics of the University of Maiduguri Teaching Hospital, Nigeria.

Materials and Methods:

After ethical approval, three consecutive early morning sputum samples were collected from patients with negative tuberculosis results. The samples were individually inoculated onto Sabouraud dextrose agar supplemented with chloramphenicol and cycloheximide in duplicate for 7 days at 37°C and 25°C, respectively. The fungal isolates were examined morphologically and microscopically and identified using the standard biochemical reagents. CD4+ cell counts were performed using flow cytometry. Self-administered questionnaires were used to assess the patients data. All patients were antiretroviral naïve.

Results:

The prevalence of PA was 12.7% in these 150 patients. Of the 19 fungal culture-positive individuals, Aspergillus fumigatus accounted for the highest proportion of the isolates (8, 42.1%) followed by Aspergillus niger (5, 26.3%), Aspergillus flavus (4, 21.1%), and Aspergillus terreus (2, 10.5%). Based on the assessment of functionality of cellular immunity, HIV participants who were negative for PA (131/150) had significantly higher mean ± standard deviation CD4 T-cell counts (245.65 ± 178.32 cells/mL) than those with aspergillosis (126.13 ± 105.27 cells/mL) (P = 0.0051). PA was relatively highest among patients with CD4+ cell counts <200 cells/mL (12. 34.3%) followed by those with CD4+ cell counts between 200 and 350 cells/mL (5, 9.6%) and least among those with CD4+ cell counts >350 cells/mL (2, 3.2%). The Chi-square test showed a significant association between the prevalence of PA and the CD4+ cell count, age, and gender (P < 0.05) but not with occupation or education level (P > 0.05).

Conclusion:

The findings from this study indicate that Aspergillus spp. is a significant etiology of acute productive cough in people living with HIV and this is related to the CD4+ cell count of coinfected persons.