Tubercular Synovitis in an Immunocompromised Patient

Abstract

Introduction:
Tuberculosis is a major health problem in immunocompromised patients, but involvement of appendicular skeleton is rare. Tuberculosis may rarely result in synovitis. In such cases other evidences of tuberculosis, such as sputum positivity, chest x-ray find-
ings etc. may be absent. The diagnosis may be missed unless there is
a high index of suspicion.

Case Report:
A 35 year old male patient with immunocompromised status. He presented with pain and swelling of left knee joint for 3 weeks with fever for 4 days. He was Human Immuno-deficiency Virus (HIV) positive and on Anti Retroviral Therapy (ART) with Tenofovir-Lamivudine-Efavirenz. His last CD4 count was 73. He previously received CAT-I Anti Tubercular Drugs for Extra-Pulmonary Tuberculosis. Synovial fluid was aspirated from his knee swelling and Cartridge Based Nucleic Acid Amplification Test (CBNAAT) was positive in the sample. Acid Fast Bacilli was detected in the Fine Needle Aspiration Cytology sample from his right axillary lymph node. The patient was treated with CAT-II Anti-Tubercular Drugs and had satisfactory improvement with this therapy.

Discussion:
Immunocompromised patients have a higher risk of developing tuberculosis and the progression of the disease is also more severe in immunocompromised patients. HIV prevalence among incident TB cases is around 4 % and 87000 new cases of HIV with TB is
emerging in India. CBNAAT has both high sensitivity and high specificity and can also
detect drug susceptibility. High index of suspicion is needed to correctly diagnose tubercular synovitis. Synovial fluid should be tested for tuberculosis in such cases.

Full text

•Agnibho Mondal, Sourav Kundu, Sitanath Mondal and Arindam Naskar
•Department of Tropical Medicine, School of Tropical Medicine, Kolkata
Tubercular Synovitis in an
Immunocompromised Patient
Introduction
•Tuberculosis is a major health problem in immunocompromised
patients and involvement of appendicular skeleton is rare in
tuberculosis.
•Tuberculosis may rarely result in synovitis. But the diagnosis may
often be missed unless there is a high index of suspicion,
especially when other usual evidences of tuberculosis, such as
sputum positivity, chest x-ray findings etc. are absent.
Presentation
•The patient is a 35 year old male and a resident of Kolkata.
He was admitted in our institution with swelling and pain in his
left knee joint for last 3 weeks. He also had fever for last 4
days. He had no history of joint stiffness or restriction of joint
movement.
•He was a known HIV patient receiving ART(TLE) for last 8
months. His last CD4 count was done 2 months back and it was
67 at that time. He had been receiving cotrimoxazole
prophylaxis since then. He was previously treated for
extrapulmonary tuberculosis (lymph node) with CAT-I Anti
Tubercular Drugs (ATD) which was completed 14 months back.
•He also had a past history of deep venous thrombosis and was
on warfarin at the time of presentation.
•He was initially suspected to have septic arthritis had been
treated with amoxicillin-clavulinic acid and linezolid for 7 days
prior to the admission but the treatment was ineffective.
Aim
•We report a case of tubercular synovitis in a 35 year old HIV
infected male patient.
•Our aim is to highlight the fact that it is necessary to be aware
of the possibility of tubercular synovitis in HIV patients
presenting with joint swelling and pain and should maintain high
index of suspicion to correctly diagnose the case.
Presented at EZAPICON (API Eastern Zone) on November 30, 2018

•Agnibho Mondal, Sourav Kundu, Sitanath Mondal and Arindam Naskar
•Department of Tropical Medicine, School of Tropical Medicine, Kolkata
Tubercular Synovitis in an
Immunocompromised Patient
Methods
•The patient was evaluated thoroughly after admission and
necessary investigations including synovial fluid study was done. MRI
of the involved joint could not be done due to financial reasons.
Examination / Initial Investigations
•On examination, left knee joint was swollen
and fluctuation was present. It was tender to
touch. The local temperature was also
elevated.
•A lymph node was also found in the left axilla
with a size of 2 cm × 1 cm.
•The x-ray of left knee joint did not show any
bony deformity or joint erosion or loss of joint
space. It only showed features suggestive of
soft tissue swelling.
•Chest x-ray of the patient was normal.
Mantoux test was negative.
X-ray of left
knee joint
showing mild
soft tissue
swelling but no
bony
deformities

•Agnibho Mondal, Sourav Kundu, Sitanath Mondal and Arindam Naskar
•Department of Tropical Medicine, School of Tropical Medicine, Kolkata
Tubercular Synovitis in an
Immunocompromised Patient
Special Investigations
•Synovial fluid was aspirated from the swollen left
knee joint and sent for investigations. The fluid was
straw colored. Gram stain and culture of the fluid
sample did not reveal any pathology. Ziehl-
Neelsen (ZN) staining of the synovial fluid sample
was also done, but no acid fast bacilli (AFB) was
detected. Cartridge Based Nucleic Acid
Amplification (CBNAAT) test was done on the fluid
sample. It was positive and was also detected as
Rifampicin sensitive.
•A fine needle aspiration cytology was done from
the palpable lymph node in the left axilla and
AFB was detected in the ZN stain of the sample.
Management
•The patient was treated with CAT II anti-tubercular
therapy along with ibuprofen to relieve pain.
•The patient responded to the treatment satisfactorily
and is still under the management.
FNAC sample from
left axillary lymph
node showing acid
fast bacilli

•Agnibho Mondal, Sourav Kundu, Sitanath Mondal and Arindam Naskar
•Department of Tropical Medicine, School of Tropical Medicine, Kolkata
Tubercular Synovitis in an
Immunocompromised Patient
Results
•Tubercular synovitis in this patient was established by positive
CBNAAT in the synovial fluid.
•The FNAC sample from left axillary lymph node was positive for
AFB which indicated disseminated tuberculosis.
Conclusion
•Immunocompromised patients have a higher risk of developing
tuberculosis and it is also more severe. In India 87000 HIV associated TB
patients emerge annually. India accounts for around 10% global burden
of HIV associated with TB.[1]
•Globally around 15% of new and relapsing tuberculosis cases are
extrapulmonary tuberculosis.[2] Bone and joint tuberculosis may account
for up to 35% cases among these extrapulmonary tuberculosis cases. [3]
But tubercular synovitis is uncommon among them and often poses a
diagnostic challenge.
•A case presenting with signs of joint inflammation (monoarticular) with
negative bacterial cultures should be suspected for tubercular synovitis.
•The Lowenstein-Jensen culture remains the gold standard, but it is
complex, expensive and time consuming. Ziehl-Neelsen stain and
fluoroscent microscopy has high specifity but low sensitivity. CBNAAT has
both high sensitivity and high specificity and can also detect drug
susceptibility. It has a very high positive predictive value (98-99%) for M.
tuberculosis in extra-pulmonary clinical specimens. [4]
•To conclude the clinician should maintain a high index of suspicion to
correctly diagnose tubercular synovitis.
Acknowledgements
•Director, School of Tropical Medicine, Kolkata, who has given us the
privilege to report this case and finally the patient who has given us
the opportunity to learn.
References
•Ministry of Health and Family Welfare. TB India Report 2018 (p. 37)
•World Health Organization. Global Tuberculosis Report 2017 (p. 67)
•Marjorie P. Golden, Holenarasipur R. Vikram. Extrapulmonary Tuberculosis: An Overview. American
Family Physician. November 1 2005 Volume 72 Number 9 (p. 1764)
•Manju Purohit, Tehmina Mustafa. Laboratory Diagnosis of Extra-Pulmonary Tuberculosis (EPTB) in
Resource-Constrained Setting: State of the Art, Challenges and the Need. Journal of Clinical and
Diagnostic Research. 2015 Apr, vol-9(4): EE01-EE06 (p. 2)