Clinical characteristics of the study population
Three hundred and seventy-nine patients were included. Of these, 93.7% were male. The median age was 38.0 [IQR: (30.0-50.0)] years. 7.4% of the patients were current or former smokers and 2.6% consumed alcohol. One hundred and thirteen patients (29.8%) had comorbidities and 136 patients (35.9%) had opportunistic infections. In addition, the median CD4+ T cell count was 23.0 [IQR: (6.0-73.8)] cells/µL and the median of HIV viral load was 4.84 [IQR: (1.9-5.5)] log10 copies/mL. Two hundred and ninety-four patients (77.6%) received ART prior to anti-NTM therapy, and the median time from initiation of ART to initiation of anti-NTM therapy was 31.0 [IQR: (4.0-127.0)] months (Table 1).
Table1: Baseline characteristics of PLWH with NTM infection.
|
|
N
|
General information
|
|
|
|
Total number of patients
|
379
|
|
Male gender, N (%)
|
355(93.7%)
|
|
Age [years], Median (IQR)
|
38.0(30.0-50.0)
|
|
Smoking (current or former), N (%)
|
28(7.4%)
|
|
Alcoholism, N (%)
|
10(2.6%)
|
|
Comorbidity, N (%)
|
113(29.8%)
|
|
Opportunistic infection, N (%)
|
136(35.9%)
|
Clinical manifestations
|
|
|
|
Fever, N (%)
|
236(63.4%)
|
|
Cough, N (%)
|
164(44.1%)
|
|
HIV wasting syndrome, N (%)
|
81(22.8%)
|
|
Abdominal pain and diarrhea, N (%)
|
68(18.3%)
|
|
Central nervous system symptoms, N (%)
|
48(12.9%)
|
|
Rash, N (%)
|
43(11.6%)
|
HIV-related indicators
NTM treatment
|
CD4+ T cell count [cells/μL], Median (IQR)
HIV viral load [log10 copies/mL], Median (IQR)
ART before NTM treatment, N (%)
ART to anti-NTM time, Median (IQR)
|
23(6.0-73.8)
4.8(1.9-5.5)
294(77.6%)
31(4.0-127.0)
|
|
Macrolides, N (%)
|
280(73.9%)
|
|
Levofloxacin/Moxifloxacin, N (%)
|
248(65.4%)
|
|
Ethambutol, N (%)
|
317(83.6%)
|
|
Rifampicin/Rifabutin, N (%)
|
248(65.4%)
|
|
Linezolid, N (%)
|
23(6.1%)
|
PLWH: people living with HIV
NTM: nontuberculous mycobacteria
IQR: interquartile range
HIV: human immunodeficiency virus
ART: antiretroviral therapy
The most frequently reported symptom was fever (63.4%). Cough was reported in 44.1% of all cases. 22.8% reported HIV wasting syndrome, 18.3% reported abdominal pain and/or diarrhea, 12.9% reported central nervous system symptoms such as headache and dizziness, and half of these patients had a combination of cryptococcal meningitis. The remaining 11.6% of patients had skin manifestations, such as rashes. (Table 1) For each year from 2013 to 2020, DNTM was account for almost half of the total number of NTM in PLWH (Fig. 1). Among the first reported positive specimens, sputum accounted for 60.7%, blood for 23.5%, stool for 6.9%, while the rest were puncture fluid (4.0%), bronchoalveolar lavage or bronchial lavage fluid (1.3%), pleural effusion (0.8%), cerebrospinal fluid (0.8%), bone marrow (0.8%), urine (0.5%), hydroperitoneum (0.3%), abdominal abscess (0.3%) and secretions from ruptured skin (0.3%). The median time to culture positivity was 13.9 [IQR: (9.5-23.5)] days.
Three hundred and twenty-six (86.0%) patients received CT scans. Lymphadenopathy, nodules, lymphadenopathy with nodules, cavities, lymphadenopathy with cavities, lymphadenopathy with cavities and nodules and consolidation account for 34.1%, 10.1%, 7.1%, 4.3%, 3.1%, 1.2% and 0.9%, respectively. The most common lymphadenopathy was mediastinal lymphadenopathy (128/148, 86.5%), followed by hilar lymphadenopathy (42/148, 28.4%) and retroperitoneal lymph (40/148, 27.0%) and lastly, axillary lymph nodes (20/148,13.5%), supraclavicular/infraclavicular lymph nodes (8/148, 5.4%), celiac lymph node (8/148, 5.4%), pelvic lymph nodes (1/148, 0.7%). In addition, 6.4% of them had no obvious abnormalities.
Treatment for NTM diseases consists of a multidrug regimen and a long course of therapy. Anti-NTM medication for patients included macrolides, levofloxacin/moxifloxacin, ethambutol, rifampicin/rifabutin, linezolid (Table 1), which lasted for 9 to 12 months. Almost all the enrolled patients received ART.
Survival Analysis
After a median of 26 months follow up, 69 patients (18.2%) died, and 48 (12.7%) lost follow-up. In 52.24% of all patients, the follow-up period exceeded 2 years. The life table method showed an overall CFR of 15.7% at 1 year, 19.0% at 2 years, 20.0% at 3 years, 22.6% at 5 years, and 27.9% at 7 years. Univariate Cox regression analysis indicated that the following parameters were statistically significant for survival: older age, HIV viral load, ART before NTM treatment, comorbidity, linezolid and DNTM. (Table 2). The probability of death in PLWH with NTM increased with time. (Fig. 2)
Table 2
Hazard ratio in univariate analysis and multivariate analysis. (Gender, age, smoking, alcoholism, comorbidity, opportunistic infection, CD4+ T cell count, HIV viral load, ART before NTM treatment, linezolid, DNTM and time to culture positivity will be added to the model using stepwise procedures.)
|
Univariate analysis
|
|
Multivariate analysis
|
Hazard ratio
|
95%CI
|
P
|
Hazard
ratio
|
95%CI
|
P
|
Age
|
1.02
|
1.01-1.04
|
0.015
|
|
1.04
|
1.02-1.06
|
0.001
|
Comorbidity
|
2.01
|
1.24-3.23
|
0.005
|
|
2.05
|
1.21-3.49
|
0.008
|
DNTM
|
1.81
|
1.12-2.90
|
0.015
|
|
2.08
|
1.17-3.68
|
0.012
|
HIV viral load
|
1.25
|
1.07-1.46
|
0.006
|
|
1.32
|
1.12-1.55
|
0.001
|
Linezolid
|
3.64
|
1.85-7.15
|
0.001
|
|
4.71
|
2.25-9.83
|
0.001
|
Gender
|
1.59
|
0.50-5.04
|
0.435
|
|
|
|
0.697
|
Smoking
|
0.86
|
0.31-2.35
|
0.764
|
|
|
|
0.411
|
Alcoholism
|
1.30
|
0.32-5.29
|
0.719
|
|
|
|
0.592
|
Opportunistic infection
|
0.98
|
0.60-1.61
|
0.946
|
|
|
|
0.411
|
CD4+ T cell count
|
1.00
|
1.00-1.001
|
0.243
|
|
|
|
0.795
|
ART before NTM treatment
|
0.53
|
0.32-0.89
|
0.015
|
|
|
|
0.221
|
Time to culture positivity
|
0.98
|
0.96-1.01
|
0.125
|
|
|
|
0.232
|
HIV: human immunodeficiency virus |
NTM: nontuberculous mycobacteria |
DNTM: disseminated nontuberculous mycobacteria |
ART: antiretroviral therapy |
1 : 95% CI for hazard ratio of CD4+ T cell count: 0.996-1.001. |
Considering that gender, smoking, alcoholism, opportunistic infection, CD4+ T cell count, time to culture positivity were also important risk factors, these factors and all parameters that were statistically significant in the univariate analysis were included in a multivariate Cox proportional hazards model. The results showed a hazard ratio of 2.05 (95% confidence interval [CI]: 1.21-3.49, P < 0.01) for patients with comorbidities compared with those without comorbidities. The hazard ratio caused by older age was 1.04 (95% CI: 1.02-1.06, P < 0.001). High levels of HIV viral load were statistically significant, and had a hazard ratio of 1.32 (95% CI: 1.12-1.55, P < 0.001). DNTM were significantly correlated with poor survival outcomes (HR = 2.08, 95% CI: 1.17-3.68, P < 0.05). (Table 2) Kaplan-Meier analysis also revealed that long-term CFR of DNTM group was significantly higher than that of the localized infection group (Fig. 3). Surprisingly, patients not treated with linezolid had a significantly longer survival time than those treated with linezolid (HR = 4.71, 95% CI: 2.25-9.83, P < 0.001).
In the subgroup analysis for patients with DNTM, time to culture positivity was negatively correlated with CFR (HR = 0.90, 95% CI: 0.84-0.96, P < 0.01). The longer time to a positive culture of the specimen, the lower the number of NTM, thus favoring survival. Older age (HR = 1.05, 95% CI: 1.02-1.08, P < 0.01), comorbidity (HR = 2.38, 95% CI: 1.14-4.96, P < 0.05) and linezolid usage (HR = 3.39, 95% CI: 1.43-8.02, P < 0.01) remained all independent risk factors for long-term CFR (Table 3).
Table 3
Hazard ratio in multivariate analysis of PLWH with DNTM. (Gender, age, smoking, alcoholism, comorbidity, opportunistic infection, CD4+ T cell count, HIV viral load, ART before NTM treatment, linezolid, DNTM and time to culture positivity will be added to the model using stepwise procedures.)
|
Hazard
ratio
|
95%CI
|
P
|
Age
|
1.05
|
1.02-1.08
|
0.004
|
Comorbidity
|
2.38
|
1.14-4.96
|
0.021
|
Linezolid
|
3.39
|
1.43-8.02
|
0.006
|
Time to culture positivity
|
0.90
|
0.84-0.96
|
0.002
|
HIV: human immunodeficiency virus. |
ART: antiretroviral therapy |
PLWH: people living with HIV. |
DNTM: disseminated nontuberculous mycobacteria. |