A Diagnosis Can Hide Another: The Value of Brain Biopsy in Neurological Lesion of HIV Patients

To the Editors: HIV patients may suffer from a large variety of diseases affecting the central nervous system (CNS).1 In these patients, a comprehensive, noninvasive, diagnosis workup, including laboratory test, brain magnetic resonance imaging (MRI), and cerebrospinal fluid (CSF) analysis, is usually sufficient to obtain a diagnosis. However, in case of negative diagnosis workup, a brain biopsy can be performed as the investigational modality of last resort.2 It can also be useful in patients who do not improve under treatment, to find an alternate diagnosis or to identify patients with dual diagnosis. Indeed, dual pathological diagnosis in CNS lesions have been previously reported in several HIV patients through autopsy studies3,4 or studies that pooled blood and CSF analysis and brain biopsy samples.5–7 This work aimed to describe 4 HIV patients with neurological disease of unknown etiology in which a brain biopsy disclosed a dual diagnosis and to discuss the value of brain biopsy in these patients. We reviewed all brain biopsies performed in the Neurosurgery Department of La Pitié-Salpêtrière Hospital, a tertiary center in Paris, France. In accordance with the ethical standards of our hospital's institutional review board, the Committee for the Protection of Human Subjects, and French law, written informed consent was not needed; however, patients were informed of their inclusion in the study (no 2214386). Between January 2008 and May 2020, 2132 brain biopsies were performed in adult patients, including 209 biopsies indicated for neurological diseases of unknown etiology. Immunodepression was reported in 87 patients, including 29 with HIV. In 4 of these patients, a dual pathological diagnosis was reported, whereas none was reported in the 58 non-HIV immunocompromised patients. CASE 1 (2012) A 53-year-old man with a 26-year history of HIV-1 infection complicated by pneumocystis pneumonia and cytomegalovirus retinitis was admitted for a persistent confusion with no fever. He was under highly active antiretroviral therapy (HAART) with poor adherence and prophylactic treatment with trimethoprim/sulfamethoxazole. HIV viral load was 202 copies per milliliter, and the CD4 count was 135 cells per cubic millimeter. Brain MRI found multiple supratentorial periventricular lesions with contrast enhancement (Fig. 1A). CSF analysis revealed lymphocytic pleocytosis with elevated CSF protein. Polymerase chain reaction (PCR) for Epstein–Barr virus (EBV), HIV, and John Cunningham (JC) viruses was positive in CSF, whereas that of toxoplasmosis and other Herpesviridae was negative. Progressive multifocal leukoencephalopathy (PML) was suspected, HAART treatment modified and foscarnet introduced. Despite these modifications, the patient condition's deteriorated with the onset of central left facial palsy. Brain MRI revealed lesions progression (Fig. 1B), but neither spectroscopy or perfusion sequences were helpful to distinguish PML, cerebral toxoplasmosis, and primary CNS lymphoma (PCNS-L). The neuropathological examination of a brain biopsy was consistent with a dual diagnosis of PML and EBV-associated B-cell PCNS-L. Foscarnet and chemotherapy as well as HAART alteration led to clinical improvement, regression of radiological lesions, and an 8-year complete remission.FIGURE 1.: Radiological and histopathological aspects of patients with dual diagnosis: PCNS-L and PML (A–M), and PCNS-L and cerebral toxoplasmosis (N–V). A and B, Case 1. A, T1-weighted brain magnetic resonance imaging (MRI) with gadolinium injection showed multiple supratentorial periventricular lesions with contrast enhancement. B, Spreading of the lesions despite 12 days of treatment with tailored antiretroviral drugs and foscarnet. C–F, Case 2. Brain MRI found FLAIR hypersignal areas without contrast enhancement into the right middle cerebellar peduncle (C) and both occipital lobes (D and E). F, Spreading of the occipital lobe lesions despite a week of treatment with ART. G–M, Case 2. G, Standard staining showed a moderate infiltrate in the brain parenchyma containing a minority of large lymphoid cells (black arrowhead) but numerous macrophages (white arrowhead) and small lymphocytes. H, Moderate infiltrate of CD3-positive T lymphocytes. I, Moderate infiltrate of large CD20-positive B-lymphoid cells. J, A cytopathogenic effect changed the structure of glial nuclei (standard staining, black arrowheads) with increased size and hyperchromatism compared with normal glial cells (white arrowhead). K, Numerous CD163-positive macrophages. L, In situ hybridization revealed EBV in the large lymphoid B cells. M, Immunolabeling showed the presence of JC virus in glial nuclei. N andO, Case 3. T1-weighted brain MRI with gadolinium injection showed periventricular contrast-enhanced lesions. P–S, Case 4. Brain MRI found 2 big lesions with contrast enhancement into the right cerebellar hemisphere and the right thalamus, and multiple small contrast-enhanced lesions. All lesions were surrounded by vasogenic edema. T–Z, Case 4. T, Standard staining showed a dense infiltrate in the brain parenchyma containing a minority of large lymphoid cells (black arrowhead) but numerous macrophages (white arrowhead) and small lymphocytes. U, Dense infiltrate of CD3-positive T lymphocytes. V, Moderate infiltrate by large CD20-positive B-lymphoid cells. W, Bradyzoite forms of toxoplasma in a cyst (standard staining, arrowhead). X, Numerous CD68-positive macrophages. Y, In situ hybridization revealed Epstein-Barr virus in the large lymphoid B cells. Z, Immunolabeling showed the presence of free forms of toxoplasma (tachyzoites, arrowhead) typical of the active disease.CASE 2 (2018) A 41-year-old man with a 13-year history of HIV-1 infection presented for progressive onset of bilateral visual deficit, balance and coordination disorders, and cognitive impairment. He stopped HAART several months ago. Brain MRI showed multiple subcortical and white matter Fluid-attenuated inversion recovery (FLAIR) hypersignal areas without contrast enhancement (Figs. 1C–E). CD4 cell count was 201 cells per cubic millimeter with an HIV viral load of 6245 copies per milliliter, and an EBV viral load of 5506 copies per milliliter. Syphilis and toxoplasmosis serologies as well as the interferon-γ–releasing assay were negative. CSF analysis was unremarkable with negative JC virus, toxoplasmosis, Herpesviridae, and EBV PCR. PML was suspected, HAART was started, but follow-up imaging revealed an increase in size of the FLAIR hypersignal zones in supra and infratentorial white matter (Fig. 1F). Brain biopsy was performed and disclosed a dual pathology of PML and EBV-associated PCNS-L (Figs. 1G–M). HAART and chemotherapy led to a clinical improvement and regression of lesions on the 2-year follow-up MRI. CASE 3 (2018) A 32-year-old man diagnosed with a 6-year history of HIV-1 infection, under HAART with poor adherence, presented with dysphasia and psychomotor impairment. Brain MRI showed bilateral callous, pericallous and periventricular contrast-enhanced lesions (Figs. 1N, O). HIV viral load was 8128 copies per milliliter, and the CD4 count was 138 cells per cubic millimeter. EBV viral load was highly positive in blood and CSF, whereas toxoplasmosis PCR was negative in both samples. Toxoplasmosis serology was positive. cytomegalovirus (CMV) meningitis was documented in CSF. Neuropathological analysis of the brain biopsy found a dual diagnosis of toxoplasmosis and EBV-associated PCNS-L. CMV was not found in the brain biopsy sample. This patient had therefore 3 concomitant neurological diseases, but only 2 were found in the brain biopsy samples. Pyrimethamine/sulfadiazine and valganciclovir followed by antilymphoma treatment led to neurological improvement. Repeated MRI at 6 months showed a significant decrease in brain lesions. CASE 4 (2020) A 32-year-old transgender woman with no known medical history fell into a coma. She was intubated and placed in an intensive care unit. Brain MRI found multiple lesions that were surrounded by vasogenic edema (Figs. 1P–S). She was diagnosed HIV-1 positive with a HIV viral load of 100,000 copies per milliliter, and CD4 cell count was 60 cells per cubic millimeter. Toxoplasmosis serology was positive. Because of the mass effect on the brain ventricles, CSF analysis by lumbar puncture was not performed. Cerebral toxoplasmosis was suspected, and antitoxoplasma therapy was introduced. Seven days later, follow-up imaging revealed new telltale lesions on the brain. Brain biopsy was therefore performed and disclosed a dual pathology of EBV-associated PCNS-L and cerebral toxoplasmosis (Figs. 1T–Z). Antitoxoplasma treatment was continued, and after 25 days ,she was discharged from the intensive care unit enabling to start HAART. The management of neurological lesion of unknown etiology in HIV patient is challenging because of the variety of diseases affecting CNS.4,8 The advent of MRI of the brain and CSF molecular analysis strongly contributed to increase the rate of diagnosis in HIV patient. Yet, in the absence of diagnosis, after failure of empirical treatment, or in quickly deteriorating patients, brain biopsy is a very useful technique.9,10 Moreover, choosing the right treatment when facing multiple diagnosis suspicion may be difficult. The rate of dual brain pathological diagnosis in autopsy studies from HIV patients ranges from 1% to 17%,3,4 although a 6% frequency of dual diagnosis in alive HIV patients have been reported.11–16 Interestingly, the dual diagnosis in our 4 patients were obtained from the same brain sample and were therefore collocated, conversely to previous reports where biopsies and CSF provided a diagnosis each.5–7 All 4 of the patients had EBV-associated PCNS-L in addition to another neurological disease. This underlines that PCNS-L is a very difficult diagnosis to establish in the absence of tissue.17,18 The concomitant existence of PCNS-L and opportunistic infection can be explained by an ineffective immunoregulation of EBV, inducing oncogenic protein expression, and subsequent loss of apoptosis and increased proliferation of lymphocytes that are targeting the infection site.19–21 In the 25 other brain-biopsied HIV patients with neurological disease of unknown etiology, a single diagnosis could be made for 23 patients (92%); most frequently EBV-associated PCNS-L (n = 6, 24%), PML (n = 4, 16%), toxoplasmosis (n = 4, 16%), tuberculosis (n = 2, 8%), immune reconstitution inflammatory syndrome (n = 2, 8%), metastasis (n = 2, 8%), CD8+ encephalitis (n = 1), measles encephalitis22 (n = 1), acute disseminated encephalomyelitis, (n = 1), aspergillosis (n = 1), and cryptococcosis (n = 1). The diagnostic yield of brain biopsy in HIV patients is high, up to 96%,9,11 and immunodepression was the sole factor associated with obtention of a histopathological diagnosis in a recent series of brain biopsies for neurological diseases of unknown etiology.23 Tissue sampling for neuropathological analysis can be obtained at low risk by stereotactic brain biopsy24 because the frequencies of permanent neurological morbidity and mortality in large series of brain biopsies are low, between 0%–4% and 0%–3%, respectively.25 Furthermore, the risk of brain biopsy complication should always be weighed against the risk borne by the natural evolution of an undiagnosed and untreated neurological disease.11 Our study underlines the importance of brain biopsy in neurological disease of unknown etiology in HIV patients, as a diagnosis can hide another. We suggest that several elements should be required to consider a brain biopsy in a HIV patient with neurological disease: (1) 3.0 Tesla brain multiparametric MRI, (2) negative comprehensive less-invasive laboratory including CSF analysis and morphologic workup, including a total-body computed tomography-scan, (3) negative pathological examination of extraneurological lesions, if present, (4) brain lesion considered accessible by a trained neurosurgical team, (5) no bleeding disorders and the possibility of maintaining platelets over 100 G/L during the first 7 days after the biopsy, and (6) validation of the brain biopsy indication during a multidisciplinary discussion. When these criteria are met cumulatively, we advocate that this procedure be considered early in the diagnosis algorithm of HIV patients especially when treatment fails, in quickly deteriorating patients, and when noninvasive diagnosis workup suggests the possibility of multiple diagnoses.