The value of wide-needle aspiration in the diagnosis of tuberculous lymphadenitis in Africa

Diagnostic accuracy of the Xpert MTB/Rif Ultra for tuberculosis adenitis

Background

The WHO recently recommended the new Xpert MTB/RIF Ultra assay (Ultra) instead of the Xpert MTB/RIF assay because Ultra has improved sensitivity. We report the diagnostic accuracy of Ultra for tuberculous adenitis in a tuberculosis and HIV endemic setting.

Methods

We obtained fine-needle aspirates (FNA) and lymph node tissue by core-needle biopsy in adult patients with peripheral lymphadenopathy of >20 mm. Ultra and mycobacterial culture were performed on FNA and tissue specimens, with histological examination of tissue specimens. We assessed the diagnostic accuracy of Ultra against a composite reference standard of ‘definite tuberculosis’ (microbiological criteria) or ‘probable tuberculosis’ (histological and clinical criteria).

Results

We prospectively evaluated 99 participants of whom 50 were HIV positive: 21 had ‘definite tuberculosis’, 15 ‘probable tuberculosis’ and 63 did not have tuberculosis (of whom 38% had lymphoma and 19% disseminated malignancy). Using the composite reference standard the Ultra sensitivity on FNA was 70% (95% CI 51–85; 21 of 30), and on tissue was 67% (45–84; 16/24) these were far superior to the detection of acid-fast bacilli on an FNA (26%; 7/27); AFB on tissue (33%; 8/24); or tissue culture (39%; 9/23). The detection of granulomas on histology had high senstivity (83%) but the lowest specficity. When compared with culture the Ultra on FNA had a sensitvity of 78% (40-97; 7/9) and tissue 90% (55-100; 9/10).

Conclusions

Ultra performed on FNA or tissue of a lymph node had good sensitivity and high specificity. Ultra had a higher yield than culture and has the advantage of being a rapid test. Ultra on FNA would be an appropriate initial investigation for lymphadenopathy in tuberculosis endemic areas followed by a core biopsy for histopathology with a repeat Ultra on tissue if granulomas are present.

The determinants and impact of diagnostic delay in lymphoma in a TB and HIV endemic setting

BACKGROUND

Little is known about the pathway to diagnosis of lymphoma in Sub-Saharan Africa, despite the increased risk of lymphoma in people living with HIV (PLHIV). The challenges of diagnosis in this setting include diagnostic confusion with extrapulmonary tuberculosis (EPTB), which commonly causes lymphadenopathy in PLHIV.

METHODS

We analysed the time to diagnosis and treatment in patients using predetermined time intervals. Univariate and multivariable analyses were performed to determine the relationship between patient and disease-specific variables with delays to diagnosis. We were particularly interested in the impact of HIV, empiric tuberculosis therapy and fine-needle aspirate for cytology (FNAC) in contributing to delay.

RESULTS

Patients (n = 163), 29% HIV-infected, waited a median of 4 weeks before seeking medical attention. It took a median of 7 weeks for the diagnosis of lymphoma to be made from the time the patient sought medical attention, termed the healthcare practitioner interval. In multivariable logistic regression analysis, diagnostic delay > 6 weeks was associated with late-stage disease (OR 2.3, 95% CI 1.1-5.2) and Hodgkin lymphoma (HL) (OR 3.0, 95% CI 1.1-8.0). HIV status was not associated with diagnostic delay (OR 0.9, 95% CI 0.3-2.2). The median time to diagnosis was a median of 4 weeks longer for patients on tuberculous (TB) therapy (n = 16, p = 0.28) and patients who underwent an FNAC (n = 63, p = 0.04). Where FNAC was performed, it was diagnostic for lymphoma in only 11%. Diagnostic delay was not associated with overall survival.

CONCLUSIONS

Time-to-diagnosis of lymphoma in South Africa was similar to that reported from high-income countries and shows significant periods of delay between the onset of symptoms to diagnosis and treatment. The longest period of delay was in the health practitioner interval. Education regarding the significance of lymphadenopathy for both patients and health care practitioners and appropriate investigative steps preferably by best-practice algorithms specific to TB-endemic areas are needed to shorten the time-to-diagnosis of lymphoma.

HIV-1 and the Mycobacterium tuberculosis granuloma: A systematic review and meta-analysis

Infection with HIV-1 greatly increases the risk of active tuberculosis (TB). Although hypotheses suggest HIV-1 disrupts Mycobacterium tuberculosis (Mtb) granuloma function, few studies have examined this directly. The objective of this study was to determine what evidence exists about the effect HIV-1 co-infection has upon Mtb granulomas. A systematic search of PubMed, Web of Science, and Medline up to 20 March 2015 was conducted, to identify studies comparing Mtb-infected tissue from HIV-1 infected and uninfected persons, or HIV-1 infected persons with stratified peripheral CD4 T cell (pCD4) counts. We summarized findings that focused on how HIV-1 changes granuloma formation, bacterial presence, cellular composition, and cytokine production. Nineteen studies with a combined sample size of 899 persons were included. Although studies frequently were limited by variable or inadequately described definitions of outcomes and analytical methods, HIV-1 was found to be associated with increased bacillary load within Mtb-infected tissue. Reductions in pCD4 counts within co-infected persons associated with both poorer granuloma formation and higher bacterial load. The high degree of heterogeneity among studies combined with experimental limitations made it difficult to conclusively support previously published and prevalent hypotheses about HIV-1/Mtb co-infection granulomas. To elucidate the validity of these hypotheses we have described areas that can be improved in future studies in order to clarify the influence HIV-1 co-infection has upon the Mtb granuloma.

The validity of the macroscopic appearance of lymph node biopsy in the diagnosis of tuberculosis

INTRODUCTION

Tuberculosis (TB) is a common disease with profound morbidity, mortality and effects on global public health. The differential diagnosis of lymphadenopathy is wide, particularly in areas where HIV is prevalent. Most hospitals in sub-Saharan Africa and across the developing world have limited, if any, histology facilities. This study will assess the validity of the assessment of the lymph nodes by their macroscopic appearance for the diagnosis of TB. Its sensitivity and specificity will be compared to full histological examination.

METHOD

This is a single-centre prospective study conducted in a remote rural district hospital in Zambia over a time period of 16 months. All patients with palpable lymphadenopathy where TB was considered in the differential diagnosis were included. The patients underwent an excision lymph node biopsy. The cut surface was judged by the operating surgeon as to the presence of caseation. The excised nodes were then sent for histological examination.

RESULTS

In total, 59.8% of patients (64 of 107 patients) in this group had a final histological diagnosis of TB. This is equivalent to the TB disease prevalence in this group of patients that have palpable lymphadenopathy in this population. The diagnostic sensitivity based on macroscopic appearance of the lymph node was 81.25% (95% CI, 69.5-89.9%). The specificity was 97.67% (95% CI, 87.7-99.6%).

CONCLUSION

This study has shown that lymph node appearance is a useful diagnostic test even without laboratory histopathological facilities in the diagnosis of TB. This assessment of the macroscopic appearance is both sensitive and specific.

Recent pattern of Co-infection amongst HIV seropositive individuals in tertiary care hospital, Kolkata

BACKGROUND

Opportunistic Infections (OIs) and co-infections are the major cause of deaths amongst HIV infected individuals and this mostly depends upon the risk factors, type of exposure and geographic region. The commonest types of infections reported are tuberculosis, chronic diarrhoea, oral candidiasis, herpes simplex virus-2, cytomegalovirus, hepatitis B virus and hepatitis C virus. Due to the scarcity of OIs data available from this region, we had designed a study to determine the frequency of different OIs amongst HIV seropositive patients.

METHODS

Analysis of the different spectrum of OIs/Co-infections were carried out with 204 HIV sero-positive patients (142 males and 62 females) who visited the HIV/AIDS Apex Clinic in a tertiary care hospital from March 2006 to March 2009. The CD4+ count was estimated using FACS Calibur, the routine smear test, serology, nested RT-PCR and DNA sequencing were carried out to determine the different OIs.

RESULTS

In this study, HIV seropositive patients were mostly from middle age group (31-40 yrs) with CD4+ counts in majority of symptomatic AIDS patients below 200 cells/mm3. The common co-infections/opportunistic infections were OC (53.43%), CD (47.05%), HSV-2 (36.76%), TB (35.29%), CMV (26.96%), HBV (15.19%) and HCV (7.35%). Dual infections, like HSV-2 & CMV (15.38%), HSV-2 & TB (14.61%), HSV-2 & oral candidiasis (24.61%) and CMV & oral candidiasis (14.61%) were significant in follow-up patients. Triple infections were also common e.g., TB, CD, OC infection occurring frequently in about 14.21% of the study population. Multiple infections like OC, TB, CD amongst the viral co-infected patients with HSV-2, HCV, CMV and HBV are also reported in this study. The genotyping analysis of the HCV co-infected HIV individuals shows that two belonged to HCV genotype 1 and 8 belonged to genotype 3.

CONCLUSIONS

A wide spectrum of OIs were observed amongst HIV-infected patients in the HIV/AIDS Apex Clinic. Oral candidiasis, CD, CMV and HSV-2, were the common OIs in those patients. This study aims to provide a clearer picture regarding infections occurring amongst HIV seropositive individuals so that the scientific findings could be translated into sustainable prevention programmes and improved public health policies.

TRIAL REGISTRATION

None.

Increased sensitivity of Mycobacterium tuberculosis Cobas Amplicor PCR following brief incubation of tissue samples on Lowenstein-Jensen substrate

The sensitivity of Mycobacterium tuberculosis Cobas Amplicor PCR (MTB-PCR) is considerably lower for tissue than for airway samples, depending on both lower bacterial content and presence of inhibitory substances in tissues. The aim of this study was to improve the sensitivity of MTB-PCR in inhibiting biopsy samples. A brief-culture method was applied to 33 inhibitory tissue samples out of 356 obtained in Laboratory I, and compared with 44/197 such samples treated by dilution in Laboratory II. We found that 2-3 days' incubation on Löwenstein-Jensen substrate (LJ) significantly increased the sensitivity of MTB-PCR in samples exerting PCR inhibition. Sensitivity was 63% before and 92% following brief-culture of inhibitory tissue samples in Lab I, compared to 46% and 50%, respectively, with dilution in Lab II. Thus, dilution did not significantly increase sensitivity in inhibiting samples. Specificities were 99.4/99.4 and 99.2/98.2, respectively. The higher sensitivity attained by the LJ-method was probably due to diffusion of inhibiting substances into the substrate, as well as to increase in numbers of bacteria after the brief-culture. This method adds substantially to the value of MTB-PCR of biopsy material.

Diagnosis of tuberculous lymphadenitis in Butajira, rural Ethiopia

Tuberculous lymphadenitis (TBLN) is a diagnostic challenge in sub-Saharan Africa, where there is a high rate of human immunodeficiency virus (HIV) infection. This study aimed to find ways to improve the diagnosis in Butajira, rural Ethiopia, where TBLN constitutes 40% of the total tuberculosis (TB) diagnosis. Among 147 clinically suspected cases, 107 (72.8%) were confirmed as TBLN by fine-needle aspiration (FNA) cytology and acid-fast bacillus (AFB) smear examination. Of the remaining 40 cases, denoted non-tuberculous lymphadenitis (NTBLN) after this smear examination, 37 (92.5%) showed a cytological pattern with neutrophil aggregates. The clinical manifestations were similar and cervical lymph nodes were the most affected in these 2 groups. 24 of the 107 TBLN cases (22.4%) and 9 (22.5%) of the other cases were seropositive for HIV infection (p > 0.5). FNA cytology combined with AFB smear examination is a good alternative to histology in rural Ethiopia where the expertise in taking biopsies is very limited. Polymerase chain reaction for Mycobacterium tuberculosis complex DNA was positive in 15 of 23 cases tested with NTBLN cytology, showing that an additional independent criterion for the presence of M. tuberculosis is needed for diagnosis in lymphadenitis cases of this kind. These findings could help to strengthen the diagnostic algorithm suggested by the National TB Control Program.

Natural history of human immunodeficiency virus disease in southern India

There are few reports of the natural history of human immunodeficiency virus (HIV) infection from Asia. In a retrospective analysis of 594 patients (72.9% male; baseline CD4 cell count, 216 cells/microL) receiving care at YRG Center for AIDS Research and Education, a tertiary HIV referral center in southern India, the mean duration of survival from serodiagnosis was 92 months. Ninety-three percent of the patients acquired infection through heterosexual contact. The most common acquired immune deficiency syndrome-defining illnesses were pulmonary tuberculosis (49%; median duration of survival, 45 months), Pneumocystis carinii pneumonia (6%; median duration of survival, 24 months), cryptococcal meningitis (5%; median duration of survival, 22 months), and central nervous system toxoplasmosis (3%; median duration of survival, 28 months). Persons with a CD4 lymphocyte count of <200 cells/microL were 19 times (95% confidence interval [CI], 5.56-64.77) more likely to die than were those with CD4 cell count of >350 cells/microL. Patients who had > or =1 opportunistic infection were 2.6 times more likely to die (95% CI, 0.95-7.09) than were those who did not have an opportunistic infection. Antiretroviral therapy for patients with low CD4 lymphocyte counts improved the odds of survival (odds ratio, 5.37; 95% CI, 1.82-15.83).

Identification of the causative organism of tuberculous lymphadenitis in ethiopia by PCR

Tuberculous lymphadenitis (TBLN) is a common form of extrapulmonary tuberculosis with multiple differential diagnoses. Demonstration of the etiologic agent by smear microscopy or culture of fine needle aspirate (FNA) specimens is often unsuccessful. FNA specimens from 40 patients presenting at a rural health center in South Ethiopia and diagnosed as positive for TBLN on the basis of clinical and cytological criteria were analyzed for mycobacterial DNA by PCR. Thirty (75%) had cervical lymphadenitis and 11 (27.5%) were seropositive for human immunodeficiency virus (HIV). Three primer sets were initially used to identify the causative agent at the genus (antigen 85 complex), complex (IS6110 insertion sequence), and species (pncA gene and allelic variation) levels. Among the forty TBLN cases, 35 (87.5%) were positive by PCR at the genus and complex levels. Based on PCR for detection of allelic variation at position 169, 24 (68.6%) of the 35 were positive for Mycobacterium tuberculosis and 6 (17.1%) were positive for M. bovis. These six were positive in additional PCR assays using the JB21-JB22 primer set, which is highly specific for M. bovis. Five (14.1%) showed amplification for both M. tuberculosis and M. bovis with the allele-specific primer set. Cooccurrence of pyrazinamide (PZA)-sensitive and -resistant M. tuberculosis in those five cases was indicated, since all were negative in assays with the JB21-JB22 primer set. This feature was seen in 3 of 11 HIV-positive and 2 of 29 HIV-negative individuals (P < 0.001).

CONCLUSION

among 35 PCR-positive cases of TBLN from southern Ethiopia, 29 (82.9%) were caused by M. tuberculosis and six (17.1%) were caused by M. bovis.

Tuberculosis in the tropics

Tropical countries bear the brunt of the global TB burden. Young children are at high risk and suffer the most severe forms of TB; adults with pulmonary cavities are the main sources of transmission. The incidence in sub-Saharan Africa is increasing as a consequence of the HIV pandemic. Smear-negative TB, which is common in children and patients who have HIV infection, is becoming a major problem in resource-poor settings where access to mycobacterial culture and histopathology is limited. Clinical case definitions are being developed to address this problem. Short courses of rifampin-based therapy are not universally available, but access is increasing. DOTS is the main strategy that the WHO is promoting to improve TB control. This is particularly important for sputum smear-positive patients. Unfortunately, the DOTS targets set by the WHO have not yet been met. Innovative, low-cost ways of supervising therapy have been developed using family members or lay supervisors. Preventive therapy in tropical countries is limited to high-risk cases (young children and HIV-infected patients who are tuberculin skin test-positive). An improved TB vaccine would dramatically improve TB control.

Diagnostic utility of fine needle aspiration (FNA) cytology in HIV-infected patients with lymphadenopathy

Sixty-five FNA cytology procedures were performed on lymph nodes in 52 HIV+ patients. Cervical lymph nodes were the commonest site of FNA cytology investigation (54%). The diagnoses were persistent generalized lymphadenopathy (38%), infection (17%), and malignancy (11%). Diagnosis could not be rendered in 25% of FNA cytology due to inadequate sampling. Of those with infection, mycobacterial disease was the commonest cause (91%), the diagnosis of which was enhanced by concurrent microbiological examination. Non-Hodgkin's lymphoma was the commonest malignancy. Sixteen lymph node FNA cytologies had subsequent tissue biopsy. There were two false-positive and four false-negative FNA cytologies. FNA cytology in HIV+ patients is most useful in the diagnosis of infection, obviating the need for tissue biopsy and allowing prompt initiation of treatment.

Tuberculous lymphadenitis, a diagnostic problem in areas of high prevalence of HIV and tuberculosis

The human immunodeficiency virus (HIV) epidemic is associated with a marked increase of tuberculosis cases. The influence of HIV on diagnostic methods for tuberculous lymphadenitis is less clear. In an environment of high HIV and tuberculosis prevalence in Blantyre, Malawi, a prospective study compared results of basic procedures diagnosing tuberculous lymphadenitis with the outcome of histology and/or culture. One hundred out-patients, aged 15-55 years, with extra-inguinal lymphadenopathy not responding to general antibiotics, entered the study. Among 52 cases, with whom all procedures were carried out in accordance with the protocol, 38 (73%) were diagnosed as tuberculous lymphadenitis; 84% of the latter (32/38) were seropositive for HIV. Needle aspirate and biopsy smears stained by the Ziehl-Neelsen technique contributed little to detecting tuberculosis, 8% and 11% respectively. In contrast, macroscopic caseation of excised lymph nodes showed a high yield of 82%, which was similar to histology, and higher than that of Löwenstein-Jensen culture (61%). The study suggested that HIV positivity of tuberculous lymphadenitis patients decreased the possibility of histology and culture both being indicative of tuberculosis (odds ratio 0.10; P = 0.06). Consequently histology results, often used as the single definitive method, failed to diagnose 18% (7/38) of tuberculosis cases. However, it was reassuring that 4 simple methods, which can safely be carried out at district level, could be expected to diagnose 80-95% of tuberculous lymphadenitis cases in a timely and cost-effective manner.

Tuberculosis in Africa: clinical presentation and management

In the last decade, sub-Saharan Africa has experienced an explosive increase in tuberculosis (TB) cases, largely as a result of the co-epidemic of human immunodeficiency virus (HIV) infection. This article reviews the essential background epidemiology of TB in sub-Saharan Africa. The clinical features and diagnostic problems of pulmonary/extrapulmonary TB in adults and children are discussed, particularly in relation to HIV infection. Different treatment regimens, their cost, adverse reactions, the ways in which HIV infection influences treatment response and the extent of drug resistance are reviewed. The recommended approaches to TB control in Africa, including methods used to prevent TB through Bacillus Calmette-Guerin and chemoprophylaxis are examined. The success achieved by good National TB Control Programmes in some African countries allows cautious optimism that this epidemic can be controlled.

The increased burden of tuberculous lymphadenitis in central Africa: lymph node biopsies in Lusaka, Zambia, 1981 and and 1990

In order to assess the effect of the HIV epidemic on lymph node biopsies in Central Africa, HIV-1 serology was tested on a cohort of patients undergoing node biopsy in Lusaka in 1990, and the histology of all lymph nodes biopsied in Lusaka in 1981 and 1990 was reviewed. One hundred and eighteen lymph nodes were biopsied in 1981 and 351 in 1990. Cases of tuberculous lymphadenitis increased from 52 (31 children and 21 adults) in 1981 to 186 (22 children, 160 adults, four patients unknown age) in 1990. Sixty-eight of 77 adults (88%) with tuberculous lymphadenitis in 1990 tested HIV-positive. Cases of histology suspicious of primary HIV lymphadenopathy and nodal Kaposi's disease also increased. Cases of malignant lymphadenopathy and overall number of surgical biopsies remained equivalent for 1981 and 1990. The study concludes that the HIV epidemic has led to a large increase in diagnostic lymph node biopsies in Lusaka, mostly through an increase in HIV-related adult tuberculous lymphadenitis.

The value of naked eye examination of biopsied lymph nodes in the diagnosis of tuberculous lymphadenitis

Tuberculous lymphadenitis is common in Central Africa, where diagnosis by histological examination of a biopsied node is often delayed. In the present study, the naked eye appearance of the cut surface of 306 consecutive biopsied lymph nodes was compared with the histological diagnosis. One hundred and eight-eight nodes showed tuberculosis on histology (including two with coexisting second pathology). One hundred and forty-eight (79%) cases of tuberculous lymphadenitis (including both with coexisting second pathology) showed noncaseating tuberculomata or caseation visible on naked eye examination. Such signs were not seen in other nodes. Other signs were seen in another 18 (10%) tuberculous nodes. It is concluded that naked eye examination of nodes provides useful information for the diagnosis of tuberculous lymphadenitis, pending confirmation by histology.

Importance of human immunodeficiency virus-associated lymphadenopathy and tuberculous lymphadenitis in patients undergoing lymph node biopsy in Zambia

The relative importance of human immunodeficiency virus (HIV)-associated lymphadenopathy amongst patients presenting for lymph node biopsy in Central Africa is unknown. HIV-1 serology and histology of patients undergoing superficial lymph node biopsy during 1989-1990 in Lusaka, Zambia, were examined in a prospective cohort study of HIV serology and by retrospective review of laboratory records. Of 727 lymph nodes biopsied in Lusaka in 1989-1990, 380 (52 per cent) showed tuberculous lymphadenitis, 160 (22 per cent) histology suggestive of primary HIV lymphadenopathy and 66 (9 per cent) nodal Kaposi's disease. HIV serology was tested in 280 adults and was positive in 91 per cent (255 patients), including 89 per cent (153 of 171) of those with tuberculous lymphadenitis, 98 per cent (63 of 64) of those with histology suspicious of primary HIV lymphadenopathy and all (24 of 24) with nodal Kaposi's disease. Other HIV-associated lymphadenopathy included nodal lymphomas and lymphoepithelial cysts. HIV serology was tested in 22 children and was positive in eight, including four of 14 with tuberculous lymphadenitis. It is concluded that HIV-associated lymphadenopathy, especially tuberculous lymphadenitis, is very common amongst patients presenting for lymph node biopsy in Central Africa.

Spectrum of opportunistic infections among AIDS patients in Tamil Nadu, India

A retrospective case note review of 100 AIDS patients attending a large Indian centre was performed. Of these 100 patients, 94% gave a history of heterosexual HIV transmission, 68% were male. The majority of females were aged 21 to 30 years. The most common mode of presentation was tuberculosis (61%), both pulmonary (46%) and extrapulmonary (15%). Oral candidiasis extending on to the oesophagus was the second most predominant opportunistic infection. This study also highlights the difficulty in detecting AIDS cases in India owing to difficulties in taking a sexual history and lack of laboratory facilities.

Bacterial infections: bone and joint tuberculosis

In many countries of the world, there is now a dual epidemic of tuberculosis and HIV disease. HIV specifically eliminates the tissue macrophages and CD4 lymphocytes, the very cells that provide immunity against tuberculosis. Tuberculosis is one of the more virulent opportunistic infections and it therefore appears fairly early in HIV disease. For the same reasons, bone and joint tuberculosis is becoming much more common. The disturbances of the lymphocyte count, ESR and antigen skin tests associated with HIV, now often make tuberculosis difficult to distinguish from other inflammatory lesions. The only change in the pattern of disease that we have so far registered is an increased incidence of disease affecting the lumbar spine. HIV-positive patients respond poorly to chemotherapy and are subject to drug sensitivity reactions. Major surgery is fraught with infectious complications and should be avoided. Once Pott's paraplegia has developed, the demise of the HIV-positive patient is rapid.