A 36-year-old male presented to our hospital in 2006 with low back ache inflammatory type with symmetric joint pains involving large joints such as shoulder joints, hip joints, knee joints, and small joints such as metacarpophalangeal joints, elbow joints, and metatarsophalangeal joints. There was associated early morning stiffness for over an hour. On examination, synovitis was present in peripheral joints with restriction of movement in all joints. Modified Schober's test was positive, and the chest expansion (<3 cm) was restricted.
On evaluation, he had anemia and elevated erythrocyte sedimentation rate (ESR) (46 mm/h) and C-reactive protein (CRP) (18 mg/L). Liver function tests and renal function tests were normal. Imaging revealed kyphoscoliosis of thoracic spine, syndesmophytes at multiple levels giving the appearance of bamboo spine [Figure 1]. Diffuse ossification of interspinous and paraspinal ligaments with fusion of thoracic and lower cervical vertebra was present. Human leukocyte antigen-B27 (HLA-B27) was positive.
In view of HLA-B27, more than 2 SpA features and typical radiological features, ankylosing spondylitis was considered. He was started on nonsteroidal anti-inflammatory drugs (NSAIDs) and dose escalated for symptomatic relief. In view of persisting symptoms and elevated ESR and CRP in spite of optimal NSAIDs, option of biologics was given. He was initially not willing but later accepted for therapy. Before biologic therapy, TB workup was done. Mantoux test was negative, and chest radiography was normal. Patient was administered infliximab by intravenous infusion. Subsequent doses were planned at 2 and 6 weeks and then every 8 weeks. There was an improvement in symptoms.
Following three doses of infliximab and 10 months after initiation of therapy, patient came with complaints of fever and cough for 1 week. On examination, breath sounds were reduced over the right side, and there was dullness on percussion. Chest radiograph showed features suggestive of pleural effusion [Figure 2]. Diagnostic thoracocentesis showed lymphocytic (total leukocyte count - 4800 cells/cumm, lymphocytes - 90%) exudative type of effusion with high adenosine deaminase (ADA) (114 IU/L). According to light's criteria (effusion protein - 6 g/dL, serum protein - 3.37 g/dL, effusion lactate dehydrogenase (LDH) - 575 U/L, and serum LDH - 325 U/L), it is an exudative type of pleural effusion. Pleural fluid showed elevated ADA levels (114 IU/L) indicating tuberculous pleural effusion. Anti-TB therapy was started.