Nodal-paranodal antibodies in HIV-immune mediated radiculo-neuropathies: Clinical phenotypes and relevance.

BACKGROUND: The frequency of nodal-paranodal antibodies in HIV-infected patients with chronic immune-mediated radiculo-neuropathies (IMRN) has not been previously described. METHODS: HIV-infected patients who met the inclusion criteria for chronic IMRN were screened for immunoglobulin G (IgG) antibodies directed against nodal (neurofascin (NF)186) and paranodal (NF155, contactin-1 (CNTN1) and contactin-associated protein(Caspr1)) cell adhesion molecules, using a live, cell-based assay. To explore potential pathogenicity, binding of human IgG to myelinated co-cultures was assessed by incubation with patients' sera positive for nodal or paranodal antibodies. Normal human serum was added as a source of complement to assess for complement activation as a mechanism for myelin injury. RESULTS: Twenty-four HIV-infected patients with IMRN were included in the study, 15 with chronic inflammatory demyelinating polyneuropathy (CIDP), 4 with ventral root radiculopathies (VRR), and 5 with dorsal root ganglionopathies (DRG). Five patients with CIDP had combined central and peripheral demyelination (CCPD). Three patients (12.7%) tested positive for neurofascin IgG1 antibodies in the following categories: 1 patient with VRR was NF186 positive, and 2 patients were NF155 positive with DRG and mixed sensory-motor demyelinating neuropathy with optic neuritis, respectively. CONCLUSION: The frequency of nodal-paranodal antibodies is similar among IMRN regardless of HIV status. Interpretation of the results in the context of HIV is challenging as there is uncertainty regarding pathogenicity of the antibodies, especially at low titres. Larger prospective immune studies are required to delineate pathogenicity in the context of HIV, and to establish a panel of antibodies to predict for a particular clinical phenotype.

Performance of the GenoType MTBDRsl in a programmatic setting, South Africa.

BACKGROUND: The GenoType MTBDRsl v2 is a molecular test designed for the rapid detection of resistance to second-line anti-TB drugs in Mycobacterium tuberculosis complex (MTBC).OBJECTIVE: To assess the use of MTBDRsl in a programmatic setting and to describe the resistance patterns in a high HIV-TB-endemic area in South Africa.METHODS: We performed a retrospective data analysis of all MTBDRsl results in patients with newly diagnosed rifampicin-resistant TB (RR-TB). We compared its performance on direct testing of smear-positive and smear-negative specimens. Results were examined to observe the detected resistance-conferring mutations.RESULTS: Of 1873 RR-TB/multidrug-resistant TB (MDR-TB), 37.4% were smear-negative and 62.5% were smear-positive. Among smear-negative specimens, the MTBDRsl showed an inconclusive rate of 61.2%, while the inconclusive rate from smear-positive specimens was 6.6%. The most common mutation observed in case of fluoroquinolone resistance occurred at the gyrA gene, codon 90 (A90V) (61/158, 38.6%), and the most common mutation in injectable aminoglycoside resistance occurred in the rrs region, A1401G (71/108, 65.7%).CONCLUSION: In HIV-TB-prevalent settings, routine use of the MTBDRsl is more effective when performed directly on smear-positive specimens. In view of currently used injectable-free regimens, this test requires revision.

Epstein-Barr virus-associated smooth muscle tumour presenting as a parasagittal brain tumour.

Dural-based brain tumours, apart from meningiomas, are rare. Epstein-Barr virus (EBV)-associated smooth muscle tumor (SMT) is a documented but rare disease that occurs in immunocompromized patients. These tumours may be located at unusual sites including the brain. We present a 37-year-old patient, positive for the human immunodeficiency virus (HIV), who was admitted after generalized tonic-clonic seizures. MRI and CT scan revealed a dural-based brain tumour, intraoperatively thought to be a meningioma, but with an eventual histological diagnosis of EBV-SMT. Clinically the patient was well postoperatively with a Glasgow coma scale score of 15/15 and no focal neurologic deficit. This case confirms the association between EBV and SMT in patients with HIV/acquired immunodeficiency syndrome (AIDS). It also highlights the need to include EBV-SMT in the differential diagnosis of intracranial mass lesions in patients with HIV/AIDS.