Published Jul 31, 2026 | 7:00 AM ⚊ Updated Jul 31, 2026 | 7:00 AM
Tuberculosis. (iStock)
Synopsis: A Kakinada-based physician’s research published in an international journal suggests the low-cost Mantoux skin test could help identify HIV-TB patients at the highest risk of death when advanced investigations such as CD4 counts are unavailable. The findings highlight the potential of an affordable bedside tool to improve patient management in resource-limited settings.
Can a ₹50 skin test help doctors identify which HIV patients with tuberculosis are most likely to survive?
Research led by an Andhra Pradesh physician suggests it can.
A study by Kakinada-based consultant physician Dr Yanamadala Muralikrishna has found that the century-old Mantoux skin test, commonly used to determine whether a person has been exposed to tuberculosis (TB), could also serve as a simple and inexpensive way to assess disease severity in patients with HIV-associated tuberculosis.
Published in the August 2026 issue of Elsevier’s Journal of Clinical Tuberculosis and Other Mycobacterial Diseases, the study argues that while the test has “limited diagnostic value” for active tuberculosis in people living with HIV, it can still provide “useful prognostic insight” in settings where advanced laboratory investigations are unavailable.
The findings are particularly relevant for low and middle income countries such as India, where tuberculosis remains one of the leading causes of death among people living with HIV and access to costly investigations such as CD4 cell counts and HIV viral load tests can still be limited in many hospitals.
“Research that enables effective patient care using locally available and affordable resources is particularly valuable for low and middle income countries,” Dr Muralikrishna said while announcing the publication of the study. He expressed hope that the findings would contribute to improving the management of HIV-associated tuberculosis in regions with limited access to advanced diagnostic facilities.
The Mantoux test, also known as the tuberculin skin test, involves injecting a small amount of purified protein derivative beneath the skin and measuring the swelling after 48 to 72 hours. Traditionally, it has been used to detect exposure to tuberculosis bacteria.
However, HIV progressively weakens the body’s immune system, often leaving patients unable to mount the immune response needed for a positive Mantoux test. Rather than treating this as a diagnostic limitation alone, the Andhra Pradesh study explored whether the degree of skin reaction could instead indicate how severely a patient’s immune system had been damaged.
“Our findings show it conveys meaningful prognostic information,” the researchers wrote, suggesting that the test may reflect the body’s remaining immune competence rather than simply the presence or absence of tuberculosis infection.
The study analysed 107 HIV-positive adults hospitalised with pulmonary tuberculosis at Rangaraya Medical College and Government General Hospital in Kakinada between 1998 and 1999, before antiretroviral therapy became widely available. Researchers also examined a comparison group of 100 HIV-negative tuberculosis patients admitted during the same period using identical methods.
The results revealed a striking pattern.
Among HIV-positive patients who developed a Mantoux reaction measuring more than 10 mm, every patient survived and was discharged within six weeks. Patients with a reaction between 5 mm and 10 mm had a mortality rate of 23.1 percent. The outlook worsened dramatically among patients who showed little or no reaction, known as anergy or an induration below 5 mm, where 62.5 percent died during hospitalisation and another 25 percent left hospital in a moribund condition.
By contrast, mortality among HIV-negative tuberculosis patients remained low even when Mantoux responses were weak. Overall mortality was just 3 percent in HIV-negative patients compared with 33.6 percent in the HIV-positive group.
“The dramatic mortality gradient across TST (Tuberculin Skin Test) categories in HIV-positive patients… supports the interpretation that tuberculin responsiveness primarily reflects HIV-related immune competence rather than tuberculosis severity alone,” the study said.
The researchers argue that the findings could give doctors working in resource-limited hospitals a practical bedside tool for identifying patients who require closer monitoring and aggressive supportive care.
“In contemporary resource-limited settings, TST reactivity may help identify HIV-positive patients warranting closer monitoring and enhanced supportive care, including nutritional rehabilitation and timely ART (antiretroviral therapy) initiation,” the paper noted, while emphasising that the test should complement, rather than replace, established clinical assessment and laboratory evaluation.
The paper also stresses that the Mantoux test is not a substitute for CD4 counts or HIV viral load testing. Instead, it offers a low-cost alternative for risk assessment where sophisticated immunological investigations remain inaccessible.
According to the authors, HIV progressively impairs cell-mediated immunity by reducing CD4 T-cell function. As immunity weakens, patients become less capable of producing the delayed skin reaction measured by the Mantoux test. This reduced response, the researchers argue, mirrors declining immune reserve and increasing vulnerability to poor outcomes.
“TST anergy may identify patients with advanced immune dysfunction who are at increased risk of adverse clinical outcomes,” the paper said.
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Although the research was conducted more than two decades ago using patients treated during the pre-antiretroviral therapy era, the authors argue that its conclusions remain relevant today.
Many patients in India continue to present with advanced HIV disease, particularly in resource-constrained settings where diagnosis is delayed or specialised investigations are unavailable. The researchers say these patients often resemble those included in the historical cohort, making the findings applicable even in the current era of widespread ART.
“Although studied in the pre-ART era, these findings retain significant relevance,” the discussion notes, adding that a substantial proportion of patients in India still present with advanced HIV disease.
The researchers also believe the study provides an important historical benchmark, demonstrating how preserving immune function dramatically improves outcomes in HIV-associated tuberculosis.
Dr Muralikrishna said the work originated during his postgraduate studies at Sri Rangaraya Medical College in Kakinada in 1998-99 under the guidance of Prof. Dr Sunnam Satya Sri from the Department of Tuberculosis and Respiratory Diseases.
The research was first presented at the 13th International AIDS Conference in Durban, South Africa, where it was selected among the top 25 abstracts from more than 5,300 submissions worldwide. It has now been published as a full-length original research article by Elsevier after further analysis and review.
While the authors acknowledge that larger prospective studies incorporating CD4 counts, HIV viral load measurements and modern diagnostics are still needed, they believe the findings reinforce the value of simple, affordable tools that can be used even in resource-constrained hospitals.
“These findings reinforce the value of simple bedside immune markers for risk stratification in resource-limited settings,” the paper concludes.
(Edited by Sumavarsha)
