Normalization of CD4+ T-lymphocyte depletion in patients without HIV infection treated for tuberculosis

Monocyte-Lymphocyte Ratio and Dysglycemia: A Retrospective, Cross-Sectional Study of the Saudi Population

Background: Abnormalities in fasting blood glucose (FBG) resulting in hypoglycemia (OG), impaired fasting glycemia (IFG), or hyperglycemia (HG) arise from disordered metabolic regulation caused in part by inflammation. To date, there is a dearth of evidence regarding the clinical utility of the monocyte−lymphocyte ratio (MLR), an emerging inflammatory index, in the management of dysglycemia. Methods: This retrospective, cross-sectional study explored MLR fluctuations as a function of glycemic control in 14,173 Saudi subjects. Data collected from 11 August 2014 to 18 July 2020 were retrieved from Al-Borg Medical Laboratories. Medians were compared by Mann−Whitney U or Kruskal−Wallis tests and the prevalence, relative risk (RR), and odds ratio (OR) were calculated. Results: MLR was significantly elevated in IFG (p < 0.0001) and HG (p < 0.05) groups compared to the normoglycemia (NG) group, and individuals with elevated MLR (>0.191) had significantly increased FBG (p < 0.001). The risk of IFG (RR = 1.12, 95% CI: 1.06−1.19, p < 0.0002) and HG (RR = 1.10, 95% CI: 1.01−1.20, p < 0.0216) was significantly increased if MLR was elevated, and individuals with elevated MLR were 1.17 times more likely to have IFG (OR = 1.17, 95% CI: 1.08−1.26, p < 0.0002) and 1.13 times more likely to have HG (OR = 1.13, 95% CI: 1.02−1.24, p < 0.0216). Conclusion: Elevated MLR is correlated with and carries a greater risk for IFG and HG. However, large prospective cohort studies are needed to establish the temporal relationship between MLR and FBG and to examine the prognostic value of this novel marker.

Development of an epitope panel for consistent identification of antigen-specific T-cells in humans

We aimed to establish a panel of MHC-peptide multimers suitable as a positive control in the detection of HLA A*0201 restricted antigen specific T cells (ASTC) by flow cytometry. MHC Dextramers were loaded with HLA A*0201 binding peptides from viral antigens and melanoma targets identified from a literature search and in silico prediction. Peripheral blood mononuclear cells (PBMC) from healthy donors were analysed with the MHC Dextramers using flow cytometry. The best performing epitopes were tested on PBMC from patients undergoing testing for Mycobacterium tuberculosis infection to assess the coverage of this epitope panel. Of 21 candidate epitopes, ASTC could be detected against 12 (57·1%) in at least one of 18 healthy blood donors. Reactivity to two or more epitopes was seen in 17 of the 18 donors (94·4%). We selected the six best-performing epitopes and demonstrated a positive response in 42 (97·7%) of 43 patient samples (healthy, latent and active M. tuberculosis infection). The selected panel of six antigenic epitopes sufficed as a positive control in the detection of ASTC in HLA A*0201. Performance was robust in different stages of latent and active M. tuberculosis infection, indicating reliability also during infection.

Human herpesvirus type 8 in tuberculosis patients with effusion

Background

Many patients with tuberculosis (TB) are seropositive for human herpesvirus type 8 (HHV-8), and many patients with primary effusion lymphoma have high levels of HHV-8 DNA in their effusions. However, the status of HHV-8 in the effusions of patients with TB remains unclear.

Methods

Blood samples were collected from 129 patients with pulmonary TB and 129 age- and sex-matched healthy controls. Forty of the TB patients had pleural or peritoneal effusions, and 38 of these effusions were available. Both blood and effusion samples were analyzed for lymphocyte and monocyte counts and/or HHV-8 antibodies and DNA.

Results

TB patients with or without effusions had significantly greater HHV-8 seropositivity (p = 0.009) and titers of HHV-8 antibodies (p = 0.005) than healthy controls. The seropositivity and blood titers of HHV-8 antibodies were similar in TB patients with and without effusions. Among TB patients with effusions, similar percentages had seropositive plasma and seropositive effusions. Plasma samples of 6 TB patients, but none of the healthy controls, were positive for HHV-8 DNA (p = 0.03). TB patients with or without effusions had lower blood lymphocyte counts and higher blood monocyte counts than healthy controls (p < 0.0001 for both). TB patients with effusions had significantly lower blood lymphocyte counts than those without effusions (p = 0.035).

Conclusions

HHV-8 had similar seroprevalence in TB patients with and without effusions. However, TB patients with effusions had lower blood lymphocyte counts than those without effusions.

Cutaneous Penicillium marneffei infection in a patient with idiopathic CD4(+) lymphocytopenia

We describe a case of cutaneous Penicillium marneffei infection in a non-HIV-infected male patient with idiopathic CD4(+) T lymphocytopenia (ICL). The cutaneous lesions were cured after the treatment of itraconazole combined with interleukin-2.

High prevalence of human herpesvirus type 8 infection in patients with pulmonary tuberculosis in Taiwan

Blood samples were collected from 101 untreated pulmonary tuberculosis (TB) patients and 101 age- and sex-matched healthy control subjects. TB patients had lower lymphocyte and a higher monocyte counts than control subjects (p <0.0001 for both). The seropositive rate of human herpesvirus (HHV) type 8 antibody was higher in patients (30/101) than in control subjects (15/101) (p = 0.01). Antibody titres in patients also exceeded those in control subjects (p 0.006). Lymphocyte and monocyte counts between seronegative and seropositive subjects were not different. Four patients were positive for HHV-8 DNA. The study revealed a significantly higher HHV-8 seroprevalence in untreated pulmonary TB patients than in general population.

CD4 cell levels during treatment for tuberculosis (TB) in Ethiopian adults and clinical markers associated with CD4 lymphocytopenia

Background

The clinical correlations and significance of subnormal CD4 levels in HIV-negative patients with TB are unclear. We have determined CD4 cell levels longitudinally during anti-tuberculosis treatment (ATT) in patients, with and without HIV co-infection, and their associations with clinical variables.

Method

Adults diagnosed with TB (maximum duration of ATT for 2 weeks, and with no history of antiretroviral therapy (ART) in HIV-positive subjects) were included consecutively in eight out-patient clinics in Ethiopia. Healthy individuals were recruited for comparison at one of the study health centers. Data on patient characteristics and physical findings were collected by trained nurses following a structured questionnaire at inclusion and on follow-up visits at 2 and 6 months. In parallel, peripheral blood CD4 cell levels were determined. The evolution of CD4 cell levels during ATT was assessed, and the association between clinical characteristics and low CD4 cell levels at baseline was investigated using regression analysis.

Results

In total, 1116 TB patients were included (307 HIV-infected). Among 809 HIV-negative patients, 200 (25%) had subnormal CD4 cell counts (<500 cells/mm³), with <350 cells/mm³ in 82 (10%) individuals. CD4 cell levels increased significantly during the course of ATT in both HIV+ and HIV- TB-patients, but did not reach the levels in healthy subjects (median 896 cells/mm³). Sputum smear status, signs of wasting (low mid upper arm circumference (MUAC)), and bedridden state were significantly associated with low CD4 cell counts.

Conclusion

A high proportion of Ethiopian TB patients have subnormal CD4 cell counts before starting treatment. Low CD4 cell levels are associated with smear positive disease and signs of wasting. The continuous increase of CD4 cell counts during the course of ATT suggest a reversible impact of active TB on CD4 cell homeostasis, which may be considered in interpretation of CD4 cell counts in HIV/TB co-infected subjects.

Idiopathic CD4 lymphocytopenia: a case of missing, wandering or ineffective T cells

Idiopathic CD4 lymphocytopenia (ICL) is a presumed heterogenous syndrome with key element low CD4 T-cell counts (below 300/mm³) without evidence of HIV infection or other known immunodeficiency. The etiology, pathogenesis, and management of ICL remain poorly understood and inadequately defined. The clinical presentation can range from serious opportunistic infections to incidentally diagnosed asymptomatic individuals. Cryptococcal and non-tuberculous mycobacterial infections and progressive multifocal leukoencephalopathy are the most significant presenting infections, although the spectrum of opportunistic diseases can be similar to that in patients with lymphopenia and HIV infection. Malignancy is common and related to opportunistic pathogens with an oncogenic potential. Autoimmune diseases are also seen in ICL with an increased incidence. The etiology of ICL is unknown. Mechanisms implicated in CD4 reduction may include decreased production, increased destruction, and tissue sequestration. New distinct genetic defects have been identified in certain patients with ICL, supporting the hypothesis of the lack of a common etiology in this syndrome. The management of ICL is focused on the treatment of opportunistic infections, appropriate prophylactic antibiotics, and close monitoring. In selected patients with life-threatening infections or profound immunodeficiency, strategies to increase T-cell counts or enhance immune function could be considered and have included interleukin-2, interferon-gamma, interleukin-7, and hematopoietic stem cell transplantation. The prognosis is influenced by the accompanying opportunistic infections and may be affected by publication bias of severe cases with unfavorable outcomes. As newer laboratory investigation techniques are being developed and targeted experimental treatments become available, our comprehension and prognosis of this rare syndrome could be significantly improved.

CD4 lymphocyte dynamics in Tanzanian pulmonary tuberculosis patients with and without HIV co-infection

Background

The interaction of HIV and tuberculosis (TB) on CD4 levels over time is complex and has been divergently reported.

Methods

CD4 counts were assessed from time of diagnosis till the end of TB treatment in a cohort of pulmonary TB patients with and without HIV co-infection and compared with cross-sectional data on age- and sex-matched non-TB controls from the same area.

Results

Of 1,605 study participants, 1,250 were PTB patients and 355 were non-TB controls. At baseline, HIV was associated with 246 (95% CI: 203; 279) cells per μL lower CD4 counts. All PTB patients had 100 cells per μL lower CD4 counts than the healthy controls. The CD4 levels were largely unchanged during a five-month of TB treatment. HIV infected patients not receiving ART at any time and those already on ART at baseline had no increase in CD4 counts after 5 months of TB treatment, whereas those prescribed ART between baseline and 2 months, and between 2 and 5 months increased by 69 (22;117) and 110 (52; 168) CD4 cells per μL after 5 months.

Conclusions

The increase in circulating CD4 levels observed in PTB in patients is acquired after 2 months of treatment irrespective of HIV status. Initiation of ART is the strongest factor correlated with CD4 increase during TB treatment.

Trial registration number

Clinical trials.gov: NCT00311298

Normal Range of CD4 Cell Counts and Temporal Changes in Two HIVNegative Malawian Populations

Longitudinal studies were carried out to determine trends in CD4 cell counts over a four year period in healthy HIV-negative adults in a rural (134 individuals) and an urban (80 individuals) site in Malawi, using TruCountTM and FACScountTM platforms. At baseline, median counts and 95% ranges were 890 (359-1954) cells per microlitre (μl) and 725 (114-1074) cells/μl respectively. 1.5% and 6% respectively had baseline counts below 350 cells/μl and 1.5% and 2.5% below 250 cells per μl. Transient dips to below 250 cells/μl were observed in seven individuals, with two individuals having persistently low CD4 counts over more than one year. Women and individuals from the urban site were significantly more likely to have "low CD4 count" (< 500 cells/μl) even when adjusted for other factors. In common with neighbouring countries, HIV-negative populations in Malawi have CD4 counts considerably lower than European reference ranges, and healthy individuals may have persistently or transiently low counts. Within Malawi, ranges differ according to the selected population.

CD4+ T-lymphopenia in HIV negative tuberculous patients at King Khalid University Hospital in Riyadh, Saudi Arabia

Tuberculosis (Tb) is a chronic infectious disease in which the cellular immunity (specifically CD4+ and CD8 lymphocytes) provides the most important defense in controlling infection. CD4 lymphopenia is a well-defined risk factor for the development of active tuberculosis in patients infected with Human Immunodeficiency Virus. In HIV - negative patients, CD4 and CD8 cell count suppression has been associated with Tb infection. Our study was designed to determine the baseline and post-treatment values of CD4 and CD8 in HIV negative patients diagnosed with active Tb in Saudi Arabian patients. We recruited twenty-eight, non-HIV patients with tuberculosis for the study group comprising 16 males and 12 females with either disseminated or localized active Tb infection. Two control groups were selected one of twenty-one matched healthy controls and the second of forty-two subjects from pool of controls of an ongoing study in same population for normal CD4 and CD8 counts. The baseline pre-treatment CD4 and CD8 counts in the study group were significantly lower than either control group. Specifically the mean ± SD of CD4 counts were 556.79 ± 298.81 in the study group vs 1,132.38 ± 259.90 in control group 1 and 1,424.38 ± 870.98 in control group 2 (p 0.000). Likewise the CD8 counts in the study group were 1,136.00 ± 512.06 vs. 1,461.90 ± 367.02 in control group 1 and 1,495.90 ± 565.32 in control group 2 (p 0.000) respectively. After treatment of tuberculosis, the study patients experienced a significant increase in their mean ± SD CD4 and CD8 cell counts, from 556.79 ± 297.81 to 954.29 ± 210.90 for CD4 cells (p 0.005) and 1136.00 ± 512.06 to 1,316.54 ± 286.17 for CD8 cells (p 0.002). Analysis of study patients with disseminated disease found significantly lower CD4 cells (but not lower CD8 cells) compared to study patients with localized disease, both at baseline and after treatment. The mean ± SD baseline CD4 cells were 247.60 ± 187.80 with disseminated vs 728.56 ± 186.32 for localized disease (p = 0.000) which rose to 842.30 ± 93.55 vs 1016.50 ± 233.51 (p = 0.033) respectively. We conclude that tuberculosis may be associated with CD4 and CD8 lymphopenia even in patients without human immunodeficiency virus infection, there was the tendency of recovery towards normality especially of the CD4 and CD8 counts after treatment, and that disseminated disease is associated specifically with profound CD4 lymphopenia.

Cryptococcosis and idiopathic CD4 lymphocytopenia

We reviewed the cases of 11 patients with cryptococcosis and idiopathic CD4 lymphocytopenia (ICL) referred to our institution in the previous 12 years, as well as 42 similar cases reported in the literature, to assess the characteristics of the infection in this population. Cryptococcosis in 53 patients with ICL had features in common with cryptococcosis in previously normal patients. ICL patients had a slight male predominance (1.2:1) and a median age of presentation of 41 years (range, 4.5-85 yr). Initial cerebrospinal fluid findings showed glucose below 40 mg/dL in 60% of the patients, a median pleocytosis of 59 white blood cells/mm (range, 0-884), and protein of 156 mg/dL (range, 25-402 mg/dL). The median CD4 count at diagnosis of ICL and at the last available measurement was 82 (range, 7-292) and 132 (range, 13-892) cells/mm, respectively, for an average follow-up of 32 months in 46 patients. Unlike previously normal patients with cryptococcosis, those with ICL had an excess incidence of dermatomal zoster (7 episodes in 46 ICL cases). Pneumocystis pneumonia was rare (1 case), casting doubt on the need for prophylaxis in patients with ICL. A favorable outcome (cured or improved) may be more common in ICL patients than in previously normal patients with cryptococcal meningitis and no predisposing factors. Identification of ICL in patients who were apparently normal before the onset of cryptococcosis appears to be useful because it predicts a favorable outcome. Patients with cryptococcal infection and ICL have an increased likelihood of developing dermatomal zoster. The long-term follow-up of these patients offers some reassurance regarding favorable prognosis.

Lymphocyte subpopulations in pulmonary tuberculosis patients

Protection against Mycobacterium tuberculosis is based on cell-mediated immunity, most importantly involving CD4⁺ and CD8⁺ T-cell subsets. The aim of this study was to evaluate CD4⁺ and CD8⁺ T-cell profiles and CD19⁺ and CD3⁻CD(16+56)⁺ populations in patients with pulmonary tuberculosis. CD4⁺ and CD8⁺ T cells, B-lymphocytes, and natural killer (NK) cells were evaluated in 75 active (APTB) and 25 inactive (IPTB) pulmonary tuberculosis cases and 20 healthy subjects (HCs). The results were compared at different stages of antituberculosis treatment in the APTB patients and also according to X-ray findings in the newly diagnosed APTB patients. The percentages of CD4⁺ T cells were significantly lower (P < .01) and those of CD3⁻CD(16 + 56)⁺ cells were significantly higher (P < .01) in APTB patients than in HCs. CD8⁺ T cells were significantly decreased (P < .05), and CD3⁻CD(16+56)⁺ cells were significantly increased (P < .01), in IPTB patients compared to HCs. The percentages of CD4⁺, CD8⁺, CD3⁻CD19⁺, and CD3⁻CD(16+56)⁺ cells showed no differences at different times of the antituberculosis regimen, and different stages of newly diagnosed APTB patients. APTB patients have a reduced percentage of circulating CD4⁺ T cells and an increased percentage of NK cells compared with healthy individuals. These cells could play important roles in the immune response to M tuberculosis infection.

Idiopathic CD4 lymphocytopenia

PURPOSE OF REVIEW

A severe decrease of CD4 T cells predisposes humans to opportunistic infections. In adults, HIV is certainly the most common cause of CD4 lymphocytopenia, but other causes, such as infections, autoimmune diseases, immunosuppressive therapy, lymphoma and idiopathic forms need to be considered. This review summarizes the current knowledge of the poorly understood syndrome of idiopathic CD4 lymphocytopenia.

RECENT FINDINGS

Little research has tried to systematically dissect this probably heterogeneic syndrome after its initial description in 1992. Numerous cases presenting with opportunistic infections have been reported. Disturbed differentiation of stem cell precursors may contribute to CD4 lymphocytopenia. Because infections and lymphoma may also cause CD4 lymphocytopenia, the distinction between cause and effect may evolve only during follow-up.

SUMMARY

The manifestation of opportunistic infections calls for the evaluation of the immune system for CD4 lymphocytopenia. The differential diagnosis of this condition in adults comprises primarily HIV infection and less often other diseases or drugs. Idiopathic CD4 lymphocytopenia is very rare. The clinical significance of low CD4 cell counts in HIV negative patients still awaits its systematic analysis. Prophylaxis of opportunistic infections is oriented at the recommendations of HIV-infected individuals and causal treatment remains experimental.

Interferon-gamma and tumour necrosis factor-alpha production by CD4+ T and CD8+ T lymphocytes in AIDS patients with tuberculosis

Tuberculosis (TB) is usually more severe in HIV-infected patients, and the immune derangement found in co-infected patients may differ from that in each isolated disease. Following mitogen stimulation of peripheral blood mononuclear cells (PBMC), interferon (IFN)-gamma and tumour necrosis factor (TNF)-alpha production was evaluated in T cells by flow cytometry, and in culture supernatants by enzyme-linked immunosorbent assay (ELISA) in 33 individuals: 11 AIDS patients with tuberculosis, six asymptomatic HIV-1-infected patients, eight patients with tuberculosis and eight healthy controls. The proportion of CD4+ T lymphocytes expressing IFN-gamma did not differ between the groups, whereas a trend towards increased proportions of TNF-alpha-expression in CD4+ T cells was observed in the TB compared to the HIV group, while intermediate values were observed in co-infected patients. Detection of IFN-gamma and TNF-alpha in CD8+ T lymphocytes was higher in TB than in HIV individuals. Co-infected patients presented intermediate values for IFN-gamma, while TNF-alpha detection was similar to that in HIV mono-infection. In conclusion, the proportion of T cells expressing IFN-gamma was relatively preserved in co-infected patients compared to TB patients, while the percentage of T cells expressing TNF-alpha was decreased, mainly in CD8+ T lymphocytes. However, the marked reduction in T lymphocyte numbers in co-infected patients led to a striking reduction of both cytokines in PBMC supernatants, a finding that is consistent with the impaired response to Mycobacterium tuberculosis.

Low CD4+ T-lymphocyte values in human immunodeficiency virus-negative adults in Botswana

CD4+-lymphocyte counts (LCs) play a crucial role in the management and monitoring of HIV infection. Variability in CD4+ LCs has been reported to occur as a result of measurement techniques and/or biological variations. We report on the CD4+ LCs of healthy human immunodeficiency virus (HIV)-seronegative adults in Botswana. Samples were obtained from HIV-seronegative blood donors. The median CD4+ LC was 726 cells/mm3 (for females, 782 cells/mm3; for males, 698 cells/mm3). The median CD8+ LC was 488 cells/mm3 (for females, 494 cells/mm3; for males, 485 cells/mm3). The median CD4+-to-CD8+ ratio was 1.57 (for females, 1.66; for males, 1.51). Our findings of low CD4+ LCs among HIV-negative adults in Botswana are significant and have important implications for the management of HIV disease in the population of this sub-Saharan African country.

Comparison of CD4 and CD8 lymphocyte counts in HIV-negative pulmonary TB patients with those in normal blood donors and the effect of antitubercular treatment: hospital-based flow cytometric study

BACKGROUND

This study was designed to flow cytometrically determine baseline and sequential values of CD4 and CD8 lymphocyte subsets in patients without the human immunodeficiency virus and with pulmonary tuberculosis (TB) and to correlate these values with those obtained from normal male blood donors and with the radiologic extent of disease and response to therapy.

METHODS

We studied 39 male patients without the human immunodeficiency virus and with sputum positive for pulmonary TB who had been admitted to Military Hospital (Cardiothoracic Center) in Pune, India. Clinical, laboratory, and radiologic evaluations of these patients were done. Hematologic parameters were assessed by an automated hematology cell counter (AcT*Diff, Coulter), and T-cell subsets (CD4 and CD8) were determined flow cytometrically (EPICS-XL, Coulter).

RESULTS

CD4 counts and percentages of CD4 were significantly lower, but CD8 values were normal, in patients with pulmonary TB when compared with values obtained in normal blood donors. The CD4/CD8 ratio was significantly lower in patients with TB. The CD4 counts normalized with antitubercular treatment. The radiologic extent of disease did not correlate well with the immune parameters studied.

CONCLUSIONS

TB is a reversible cause of CD4 lymphocytopenia and is associated with normal numbers of CD8 cells. The radiologic extent of disease does not seem to determine the immune response.

Linfopenia em doentes submetidos a ventilação mecânica por exacerbação de insuficiência respiratória crónica: estudo prospectivo

OBJECTIVES

Evaluate and characterize lymphopenia in patients admitted to the Intensive Care Unit (ICU) for mechanical ventilation due to aggravated chronic respiratory failure and its probable relation to severity.

MATERIAL AND METHODS

Prospective study over a period of 6 months with another 6 months follow-up after ICU discharge. The study included 24 patients, 22 males, with mean APACHE II of 19,7, three of whom with capacity for outpatient follow-up. Lymphocyte subpopulations were determined on admission and every 7 days after mechanical ventilation. Patients with evidence of infection or previous immunossupression, with the exception of steroids, were excluded from the study.

RESULTS

Lymphopenia was found in 79,2% of patients with depletion of all lymphocyte series, although with greater expression for B lymphocytes CD19+. This depletion showed no relation with serum steroid levels, and although related to greater clinical severity, no correlation was found with mortality. Lymphocyte values recovered progressively during admission.

CONCLUSIONS

Lymphopenia is frequent among ventilated patients with chronic respiratory exacerbation. It's a non-selective depletion, more evident with CD19+ B lymphocytes. These patients present higher severity scores but no difference in mortality. Outpatient follow-up was difficult and inconclusive.

Immune biology of macaque lymphocyte populations during mycobacterial infection

Immune responses of lymphocyte populations during early phases of mycobacterial infection and reinfection have not been well characterized in humans. A non-human primate model of Mycobacterium bovis bacille Calmette-Guerin (BCG) infection was employed to characterize optimally the immune responses of mycobacteria-specific T cells. Primary BCG infection induced biphasic immune responses, characterized by initial lymphocytopenia and subsequent expansion of CD4+, CD8+ and gammadelta T cell populations in the blood, lymph nodes and the pulmonary compartment. The potency of detectable T cell immune responses appears to be influenced by the timing and route of infection as well as challenge doses of BCG organisms. Systemic BCG infection introduced by intravenous challenge induced a dose-dependent expansion of circulating CD4+, CD8+ and gammadelta T cells whereas, in the pulmonary compartment, the systemic infection resulted in a predominant increase in numbers of gammadelta T cells. In contrast, pulmonary exposure to BCG through the bronchial route induced detectable expansions of CD4+, CD8+ and gammadelta T cell populations in only the lung but not in the blood. A rapid recall expansion of these T cell populations was seen in the macaques reinfected intravenously and bronchially with BCG. The expanded alphabeta and gammadelta T cell populations exhibited their antigen specificity for mycobacterial peptides and non-peptide phospholigands, respectively. Finally, the major expansion of T cells was associated with a resolution of active BCG infection and reinfection. The patterns and kinetics of CD4+, CD8+ and gammadelta T cell immune responses during BCG infection might contribute to characterizing immune protection against tuberculosis and testing new tuberculosis vaccines in primates.

Detection of Mycobacterium tuberculosis DNA from peripheral blood in patients with HIV-seronegative and new cases of smear-positive pulmonary tuberculosis by polymerase chain reaction

Tuberculosis is still one of the most important cause of mortality and morbidity in many countries and there is a need for new methods for accurate and rapid diagnosis of tuberculosis. To determine the sensitivity and specificity of polymerase chain reaction (PCR) method, we have evaluated Mycobacterium tuberculosis DNA in peripheral blood samples with PCR technique in adult patients with human immunodeficiency virus (HIV)-negative and new cases of smear-positive pulmonary tuberculosis. We investigated the relationship between characteristic of the patients, radiological extension of the disease, sputum smear grade, presence of cavity, body-mass index (BMI) serum albumin level, total delay time and PCR positivity. Forty patients (33 male and 7 female; mean age 37.8 +/- 14.1) and 20 healthy control subjects (13 male and 7 female; mean age 35.6 +/- 7.3) were enrolled in this study. PCR was positive in 16 of 40 (40%) patients with pulmonary tuberculosis and negative in 24 of 40 (60%). None of the healthy controls had positive PCR results. The overall sensitivity specificity and accuracy of the PCR assay was 40, 100 and 60%, respectively. We found the positive correlation between PCR positivity and sputum smear grade (r=0.46, P=0.003) radiological extension of the disease (r=0.69, P=0.001), presence of cavity (r=0.90, P=0.001). We conclude that the detection of M. tuberculosis DNA from peripheral blood by PCR technique is useful for the rapid diagnosis of tuberculosis patients with HIV-negative. Hematogenous dissemination was important in tuberculosis patients and peripheral blood samples were suitable and easy materials. However, standardization of the PCR method must be ensured for the diagnosis of tuberculosis.

Risk factors for Pneumocystis carinii pneumonia in kidney transplant recipients: a case-control study

OBJECTIVE

To analyze risk factors for Pneumocystis carinii pneumonia (PCP) in kidney transplant recipients.

STUDY DESIGN

In a case-control study, 17 PCP cases diagnosed between July 1994 and July 2000 were matched with two controls each (previous and subsequent kidney transplant recipients who did not develop PCP during the same follow-up period). Demographics, organ origin, human leukocyte antigen (HLA) mismatches, use of poly- or monoclonal anti-CD3 antibodies (Po/MoAb) for induction or rejection treatment, rejection episodes, cumulative steroid dose for rejection treatment, immunosuppressive regimens, and other infections were analyzed.

RESULTS

No significant differences were seen in gender (male 10 vs. 15), mean age (39.7 vs. 35.4 years), organ origin (cadaver donor 13 vs. 19), HLA mismatches, or Po/MoAb use in induction treatment. Significant differences were observed in PCP cases for rejection history (P=0.02), and median and total number of rejection episodes (P=0.0018). The relative risks for PCP for 1, 2, and > or =3 rejection treatments vs. no such treatment were 1, 1.05, and 6.30, respectively (P=0.021). The relative risk for PCP for steroid-resistant rejection was 4.34 (95% confidence interval [CI], 1.04-18.89) (P=0.019), and that for the use of Po/MoAb for rejection treatment was 7.23 (95% CI, 1.28-49.34) (P=0.006). The relative risk for PCP for 0, 1, and > or =2 previous or concomitant cytomegalovirus (CMV) infection vs. no such infections were 1.0, 2.32, and 13.0, respectively (P=0.012). The relative risks for PCP for tuberculosis (TB) was 18 (95% CI, 1.76-852.03), that for bacterial pneumonia was 14.22 (95% CI, 2.16-150.23), and that for hepatitis C virus infection was 5.25 (95% CI, 1.03-28.91). Immunosuppressive regimens with tacrolimus, mycophenolate mofetil (MMF), steroids (P=0.06), and MMF as a single variable (P=0.05) were more frequently used in cases. Primary trimethoprim-sulfamethoxazole prophylaxis failure was observed in 12 patients in association with heavy immunosuppression and concomitant infections.

CONCLUSIONS

The risk of PCP in kidney transplant recipients is related to the number and type of rejection treatments. It is also related to the occurrence of CMV infection, and to other immunomodulating infections such as TB and hepatitis C, and might also be increased with the use of newer and more potent immunosuppressive agents. Primary prophylaxis failure may occur in association with some of these risk factors.

Increasing CD4+ T cells specific for tuberculosis correlate with improved clinical immunity after highly active antiretroviral therapy

Treatment advances have led to dramatic clinical improvements for patients with HIV-1 infection. These clinical improvements reflect treatment-related improvements in immune function, which are most striking in individuals who develop exaggerated immune inflammatory responses to occult opportunistic infections. The mechanisms accounting for these exaggerated immune responses are unknown. To gain insight into these mechanisms, we intensively studied a subject untreated for disseminated tuberculosis and HIV-1 coinfection who then began treatment for both diseases. We examined the changing frequencies of Mycobacterium tuberculosis (MTB)-specific CD4(+) T cells that produced interferon gamma (IFN-gamma) after short-term stimulation with MTB antigen, and we compared these frequencies with those in HIV-1-seronegative subjects with and without prior exposure to MTB antigens. For the HIV-1/MTB-coinfected subject, the proportion of peripheral blood CD4(+) T cells expressing MTB-specific IFN-gamma was 8.6% at 11 days, 11% at 33 days, and 33% at 95 days after starting treatment for HIV-1. CD4(+) IFN-gamma(+) T cells had a CD45RA(-)CD62L(-) (effector memory) phenotype and most coexpressed interleukin 2. Median frequencies of CD4(+) IFN-gamma(+) T cells from six subjects without and nine subjects with prior exposure to MTB antigens were 0.06 and 0.46%, respectively. We conclude that individuals starting treatment for disseminated tuberculosis and HIV-1 coinfection can accumulate remarkably large numbers of MTB-specific CD4(+) T cells in the peripheral blood. The rapid expansion of antigen-specific effector CD4(+) T cells is one mechanism to explain immediate improvements in clinical immunity after HIV-1 treatment. This mechanism provides a theoretical framework to understand the unusual inflammatory responses recently reported to occur after starting HIV-1 treatment.

Immunophenotypic characterization of peripheral T lymphocytes in Mycobacterium tuberculosis infection and disease

The cellular immune response probably plays a pivotal role in determining the clinical outcome after exposure to Mycobacterium tuberculosis. We used multi-parameter flow-cytometry to evaluate the distribution of T-lymphocyte subsets during infection and disease caused by M. tuberculosis. Samples were obtained from 71 volunteers to identify the T CD4+ and CD8+ lymphocyte numbers, and the activation plus memory/naïve phenotypes, as defined by CD38, HLA-DR, CD45RA and CD27 markers. Subjects were divided into 18 healthy volunteers without detectable reaction to purified protein derivative (PPD-), 18 health care workers with a recent conversion to PPD, 20 patients with active pulmonary tuberculosis (TBC) and 15 patients with treated TBC at 6 months of therapy. By multiple-comparison analyses, the T CD4+ lymphocyte number of the TBC group was lower than the PPD- group (P < 0.05). This difference was apparently lost after treatment. The higher and the lower number of naïve T CD4+ cells was observed in the PPD- and TBC group, respectively. CD8+ T lymphocytes were also statistically different among the four groups (P = 0.0002), lower in the TBC group (P < 0.05). CD8+ T lymphocyte activation was evaluated by the CD38 and HLA-DR surface expression. The percentage distribution of these markers was statistically different between the four groups (P = 0.0055). TBC patients had a higher percentage of CD38+ cells and mean fluorescence index, suggesting an overall increase of cell activation. These results suggest that peripheral T lymphocytes reflect cellular activation during TBC, along with possible redistribution of naïve, memory/effector and late differentiated memory/effector phenotypes in the peripheral blood after infection and disease caused by M. tuberculosis.

High mortality and severe immunosuppression in hospitalized patients with pulmonary tuberculosis and HIV-2 infection in Guinea-Bissau

The aim of this study was to prospectively compare the clinical outcomes in HIV-2-infected and HIV-negative patients with culture-confirmed pulmonary tuberculosis, evaluate immunological changes and investigate risk factors for decreased survival in HIV-2-positive subjects. From 1994 to 1997, 127 consecutive patients with pulmonary tuberculosis were included at the Raoul Follereau Hospital in Bissau, the capital of Guinea-Bissau. All subjects were initially hospitalized, and then followed to the end of the 8-month treatment period. CD4 T-lymphocyte counts were determined by flow cytometry before, during and at the end of the treatment period. The prevalences of HIV-1, HIV-2 and HIV-1/HIV-2 dual reactivity were 8.7%, 23.6% and 9.4%, respectively (95% confidence intervals 3.8-13.6, 16.2-31.0 and 4.4-14.5, respectively). The mortality rate during the study period was significantly higher in HIV-2-positive (p < 0.01) and HIV-1/HIV-2 dually reactive (p < 0.01) patients than in HIV-negative individuals (52.9, 83.3 and 8.7 per 100 person-years, respectively). In HIV-1-positive patients the mortality rate was 30.8/100 person-years (p = NS). Baseline total CD4 cell counts were 213, 104, 235 and 624 x 10(6)/l (% CD4 = 17, 15, 20 and 40) among HIV-1-, HIV-2- and HIV-1/HIV-2-positive and HIV-negative subjects, respectively. The median rates of change per year of total CD4 cell counts in HIV-2-positive and HIV-negative subjects were 66 and 340 x 10(6)/l, respectively (interquartile ranges -78-249 and 21-624). In conclusion, we found a significantly higher mortality rate in HIV-2-positive compared to HIV-negative individuals. Baseline CD4 cell counts were markedly suppressed and similar in all 3 HIV-positive groups, and in a multivariate logistic regression analysis a value of CD4 percentage of < 10 was shown to be an independent predictor of decreased survival in HIV-2-infected subjects.

Profound T-lymphocytopenia and cryptococcemia in a human immunodeficiency virus-seronegative patient with disseminated tuberculosis

A 47-year-old human immunodeficiency virus-seronegative West African man who presented in extremis with cachexia, lymphadenopathy, multiple organ dysfunction, and marked T-lymphocytopenia received the diagnosis of disseminated tuberculosis, cryptococcal pneumonia, and cryptococcemia. His subsequent course and our review of the literature suggest that the profound T-lymphocytopenia and ensuing cryptococcal disease were likely attributable to disseminated tuberculosis.

CD4(+) T-lymphocytopenia and Pneumocystis carinii pneumonia in a patient with miliary tuberculosis

We report a case of miliary tuberculosis (MTB) occurring after extracorporeal shock-wave lithotripsy in a 51-year-old man. The MTB was complicated by pancytopenia and CD4(+) T-lymphocytopenia, which was responsible for Pneumocystis carinii pneumonia. Hematological parameters returned to normal in response to antituberculous treatment.

Alteration in CD29(high) CD4(+) lymphocyte subset is a common feature of early HIV disease and of active tuberculosis

Peripheral CD4 T-cell depletion has been observed in human immunodeficiency virus (HIV)-negative patients with pulmonary tuberculosis (TB). To investigate more accurately this alteration, we studied peripheral blood CD45RA(+) and CD29(high) CD4 subsets in 79 TB patients with (HIV(+)TB(+)) or without (HIV(-)TB(+)) HIV infection, 85 HIV-infected patients without TB (HIV(+)TB(-)), and 43 healthy controls, all living in West Africa. The high proportion of CD4(+)CD29(high) T cells observed in controls was dramatically decreased in CDC-A stage HIV(+)TB(-) patients. CD45RA(+) CD4(+) T cells were depleted during the CDC-B stage. Both the percentage and the absolute count of CD29(high)CD4(+) T cells were decreased in HIV(-)TB(+) and HIV(+)TB(+) patients versus controls, but CD45RA(+)CD4(+) T cells were not decreased in TB patients without HIV-infection. Although distinct alterations in the CD4(+) T-cell homeostasis are involved in TB(-) versus HIV-infected subjects, our data suggest that the CD29(+)CD4(+) T-cell depletion observed during the early HIV disease contributes to the risk of active TB, by reducing the pool of T cells able to relocalize to the sites of the M. tuberculosis multiplication.

Tuberculosis-associated severe CD4+ T-lymphocytopenia in HIV-seronegative patients from Dakar. SIDAK Research Group

OBJECTIVES

To determine the frequency and associated features of severe CD4+ T-lymphocytopenia (<300 cells/mm(3)) in HIV-seronegative patients with tuberculosis.

METHODS

Statistical analysis of 430 consecutively enrolled HIV-seronegative inpatients with tuberculosis in two teaching hospitals in Dakar, Senegal.

RESULTS

The mean CD4 + cell count was 602+/-318.3 cells/mm(3). CD4 + cell counts were below 300 cells/mm(3)in 62 patients (14.4%). Patients with fewer than 300 CD4+ cells/mm(3)differed from those with higher counts in being less likely to have a positive smear for acid-fast bacilli; in having a higher frequency of extrapulmonary involvement (pleural effusion, adenopathy and miliary disease) and oral candidiasis; and in having smaller tuberculin reactions, lower haemoglobin levels, less cavitation and less patchy infiltration. After adjustment for gender and age, all differences remained except miliary disease.

CONCLUSIONS

A substantial percentage (14.4%) of HIV-seronegative hospitalized patients for tuberculosis in a West African country presented with severe CD4 + T-lymphocyte depletion and had clinical and radiographic features indicative of more advanced disease and accompanying immunodepression. These results and those already published suggest that tuberculosis should be regarded as one of the diseases associated with a subgroup of patients with "idiopathic CD4 + T-lymphocytopenia".

Role of CD4:CD8 ratio in predicting HIV co-infection in patients with newly diagnosed tuberculosis

Because of the clinical implications of Human Immunodeficiency Virus (HIV) status on treatment of tuberculosis (TB) and in view of the low percentage of patients in whom HIV testing is performed, we evaluated immunological features of 54 patients with newly diagnosed TB and its ability to predict HIV co-infection. All 54 patients had initially unknown HIV status and had no other Acquired Immunodeficiency Syndrome (AIDS) defining illnesses. Twenty-two patients were found to be HIV seropositive and 32 were seronegative. The median CD4 and CD8 counts were statistically different between the HIV seropositive and seronegative patients, however, there was overlap between the two groups. The median CD4:CD8 ratio was 0.17 in HIV seropositive patients and 1.95 in the seronegative patients and had minimal overlap (p < 0.0001). A CD4:CD8 ratio < or = 0.7 gave a sensitivity of 100%, specificity of 94%, positive-predictive value of 92% and a negative-predictive value of 100% in predicting HIV co-infection. In conclusion, HIV-co-infection in patients with newly diagnosed TB could be predicted on the basis of the CD4:CD8 ratio.

Dichotomy of cytokine profiles in patients and high-risk healthy subjects exposed to tuberculosis

To better understand the role of cytokines in susceptible and resistant subjects exposed to Mycobacterium tuberculosis infection, intracellular gamma interferon (IFN-gamma) and interleukin-4 (IL-4) in ex vivo peripheral blood-derived CD4(+) T cells were examined by flow cytometry. Of the 37 individuals examined, 20 had clinical evidence of pulmonary tuberculosis and showed acid-fast bacilli in the sputum. Other individuals in close contact with these patients showed no evidence of disease. Patients had a higher number of CD4(+) T cells expressing IFN-gamma and IL-4 in unstimulated cultures compared to healthy subjects. Despite this, the ratio of IFN-gamma(+) to IL-4(+) CD4(+) T cells was similar in both groups. The Th1 response seen in CD4(+) T cells in patients was also observed in the overall pattern of IFN-gamma and IL-4 detected in control culture supernatants by enzyme-linked immunosorbent assay (ELISA). However, after in vitro stimulation of PBMC with heat-killed M. tuberculosis there was a significant reduction in the percentage of IFN-gamma(+) CD4(+) T cells (P < 0.001) in patients. This trend was reflected in the IFN-gamma ELISA assay with supernatants derived from stimulated cultures. However, the accumulated levels of IFN-gamma were higher than those for IL-4. The reduction of IFN-gamma(+) CD4(+) T cells resulted in the dominance of IL-4(+) CD4(+) T cells in 13 patients (P < 0.05). The elevated levels of IL-4(+) CD4(+) T cells seen in patients may contribute to the downregulation of IFN-gamma expression and the crucial effector function of CD4 T cells, leading to the persistence of disease and the immunopathology characteristically seen in patients. Preliminary data on the indicators of apoptosis in antigen-stimulated cultures in PBMC derived from patients are presented. Of the 17 high-risk healthy individuals examined, 11 differed in that, after mycobacterial-antigen stimulation, there was an enhancement in IFN-gamma(+) CD4(+) T cells.

Tuberculosis I: a conceptual frame for the immunopathology of the disease

An analysis of the cellular and humoral immune responses after bacille Calmette-Guerin (BCG) vaccination and during tuberculosis treatment favors the hypothesis of an immune defence developed in four overlapping successive stages. The initial immune response is innate. The following two intermingle innate and specific responses against low molecular weight oligopeptidic and nonpeptidic antigens, as muramyldipeptide and trehalose dimycolate, and large molecular weight nonpeptidic antigens such as lipoarabinomannan. The ultimate specific response is directed against protein antigens as Antigen 60. BCG and primary tuberculosis (TB) infections induce cellular and humoral immune responses essentially against oligopeptidic and small and large molecular weight nonpeptidic antigens. Immune responses against non-peptidic substances contribute to the immunoprotection of the infected person who develops a primary infection. Some infected people allow the expression of the immunosuppressive activity of the pathogen. This results in the synthesis of interleukin-10 (IL-10), which suppresses the formation of interferon-gamma (INF-gamma) and IL-2, and of IL-6, which suppresses T-cell responses. These patients have a skewed immune response against non-peptidic antigens and present with symptoms. They will not recover unless responses directed against proteinic antigens occur, which restore INF-gamma and IL-2 production. The formation of immumoglobulin-G (IgG)-type antibodies and of a cellular immunity against mycobacterial peptidic antigens is essential for a good protection against a post-primary infection.

Decreased CD4 and increased CD8 counts with T cell activation is associated with chronic helminth infection

We have previously reported the presence of marked immune dysregulation with a dominant Th2 profile, in a population of Ethiopian immigrants (ETH) in Israel heavily infected with helminths. In order to characterize better this immune dysregulation we studied by flow cytometry the expression of several activation markers on peripheral T cell populations, and lymphocyte apoptosis, in blood samples obtained from 63 'new' ETH (recently arrived), 18 'old' ETH (> 5 years since immigration) and 34 non-Ethiopian Israelis. The main findings in the 'new' ETH group in comparison with the non-Ethiopian controls were: (i) decreased CD4 and increased CD8 lymphocyte counts; (ii) elevated levels of activated T cells (CD3, CD4 and CD8) expressing HLA-DR; (iii) decreased levels of 'naive' CD4+ cells (CD45RA+), with increased levels of 'memory' CD4+ cells (CD45RO+); (iv) decreased numbers of CD28+ CD8+ lymphocytes; (v) marked increase in lymphocyte apoptosis. These T cell alterations and activation profile remained unchanged in 10 'new' ETH in whom the helminth infections persisted for 6-11 months. In contrast, in 18 'old' ETH, without helminth infections, the T cell activation profile was within the normal range. These findings suggest that chronic helminth infections may have a profound effect on the immune system of the host that disappears after eradication of these infections and adjustment to the new environment. It should therefore be taken into consideration for every immunomodulation therapy and especially in vaccine design and trials, in regions endemic for helminth infections.

Behçet's-like syndrome associated with idiopathic CD4+ T-lymphocytopenia, opportunistic infections, and a large population of TCR alpha beta+ CD4- CD8- T cells

Herein we report a patient with Behçet's like syndrome, idiopathic CD4+ T-lymphocytopenia, opportunistic infections, and a large polyclonal population of TCR alpha beta + CD4- CD8- T cells. Microfluorimetric analysis of peripheral blood mononuclear cells revealed CD4+ T-cell counts of 10 +/- 5/mm3. The CD3+ T cells were 99% TCR alpha beta +, of which 74 +/- 5% were CD4- CD8-. No clonal populations were detected by southern analysis for T-cell receptor V beta gene rearrangements. No evidence of human immunodeficiency virus infection was present, although nocardia, candida, pneumocystis, cytomegalovirus, and herpes infections were documented. The concomitant presence of opportunistic infections and a large population of TCR alpha beta + CD4- CD8- T cells suggests a pathogenic association and an intense immune response to microbial lipid or lipoglycan antigens presented in the context of CD1 molecules. This case demonstrates the potential for idiopathic CD4+ T-lymphocytopenia to occur in Behçet's-like syndrome with lethal consequences.

Tuberculosis and human immunodeficiency virus infection

Mycobacterium tuberculosis infects one third of the world's population, and tuberculosis remains one of the most common infectious diseases of humans. From a global perspective, tuberculosis may be one of the most common HIV-related opportunistic infections. HIV immunosuppression has had a dramatic influence on the epidemiology, natural history and clinical presentation of tuberculosis. Treatment is highly effective for drug susceptible tuberculosis and has been shown to have a significant impact on resistant, especially multidrug-resistant, tuberculosis if started promptly. Directly observed therapy and rigorous adherence to infection control principles have helped control the tuberculosis epidemic in the United States.

Mycobacterial infections: are the observed enigmas and paradoxes explained by immunosuppression and immunodeficiency?

The enigmas and paradoxes observed in tuberculous patients, in Bacille Calmette-Guérin-vaccinated people and in Bacille Calmette-Guérin-treated cancer patients have been examined, in an attempt to explain them through the mechanisms of immunodeficiency and immunosuppression. A dual effect is postulated: an immunosuppression induced by the infecting mycobacteria that adds to a pre-existing or emerging state of immunodeficiency of the infected individual. The immunological cellular and humoral anergies observed at the beginning of a tuberculous therapy are usually lifted after the first two weeks of treatment. This restoration of immune responsiveness may be attributed to the destruction or to the growth inhibition of immunosuppressive mycobacteria. The observation that drugs cytocidal in vitro do not always sterilize the patients under treatment whereas bacteriostatic drugs do, may find an explanation in the dual immunosuppression induced by cytocidal drugs and mycobacteria. The fact that Bacille Calmette-Guérin applied as an immunotherapy to residual cancer has either a favorable or an unfavorable action may be due to the immunosuppressive activity attached to some Bacille Calmette-Guérin strains and to some cancers. The variable protective activity of Bacille Calmette-Guérin vaccines may be due to the immunological status of the vaccinated people and the compositional differences between strains. The protective activity of subunit vaccines in experimental models can be attributed to the elimination of immunosuppressive factors present in whole killed mycobacteria.

A pilot study of antituberculosis combinations comparing rifabutin with rifampicin in the treatment of HIV-1 associated tuberculosis. A single-blind randomized evaluation in Ugandan patients with HIV-1 infection and pulmonary tuberculosis

SETTING

This pilot study was conducted at the Joint Clinical Research Centre (JCRC) in Kampala, Uganda, where tuberculosis (TB) is an epidemic health problem aggravated by the HIV-1 pandemic.

OBJECTIVE

To evaluate the feasibility of a larger phase III trial utilizing rifabutin as a substitute for rifampicin in short-course therapy for pulmonary TB.

DESIGN

Single-blind randomized trial in 50 patients with new onset smear- and culture-positive pulmonary tuberculosis and HIV-1 infection. Comparison of daily, intermittently supervised 6-month treatment regimens of rifabutin versus rifampicin, together with isoniazid, ethambutol and pyrazinamide.

RESULTS

Rifabutin- and rifampicin-containing regimens had comparable efficiency. However, rifabutin-treated patients had significantly more rapid clearance of acid-fast bacilli from sputum at 2 months (P < 0.05, Fisher exact test) and over the entire study period (P < 0.05, logrank test) than rifampicin-treated patients. The presence of cavitary disease was associated with a longer sputum conversion time for patients treated with either regimen. No major adverse events requiring dosage reduction or withdrawal of any study medication were seen in either treatment group. Mean absolute peripheral blood CD4 T lymphocyte counts increased by 28% from week 0 to week 12 in all subjects (334-427/microliters, respectively). An unexpected finding was the isolation of Mycobacterium africanum from 49% of the sputum cultures. This is the first report indicating a high prevalence of M. africanum in human TB in Uganda.

CONCLUSION

Short-course antituberculosis regimens containing rifabutin or rifampicin are both safe and efficacious in the treatment of HIV-1 associated tuberculosis. Rifabutin-containing regimens were associated with earlier sputum smear and culture conversion.