Management of infections by the human polyomavirus JC: past, present and future

Progressive Multifocal Leukoencephalopathy: A Case Study

Progressive multifocal leukoencephalopathy is a rare, highly fatal demyelinating brain infection caused by the JC virus. This infection is associated with immunosuppressive agents and is emerging in the transplant population. There has never been a documented case of progressive multifocal leukoencephalopathy in a transplant recipient receiving sirolimus. We present a study, in which the JC virus was found in a 68-year-old man who had received a postorthotopic heart transplant 3 years earlier and who was receiving sirolimus and prednisone for immunosuppression. We review the clinical presentation, diagnosis, current treatment options, and the outcomes of progressive multifocal leukoencephalopathy in transplant recipients.

Metabolische Störungen

Im folgenden Kapitel werden die verschiedenen metabolischen Störungen betrachtet. Zunächst wird auf die allgemeinen und spezifischen neurologischen Komplikationen bei Organtransplantation eingegangen. Dann geht es um die metabolischen Enzephalopathien: Störungen der Gehirntätigkeit bei angeborenen und erworbenen Stoffwechselerkrankungen im engeren Sinn, Elektrolytstörungen, Hypovitaminosen, zerebrale Folgen einzelner Organdysfunktionen, zerebrale Hypoxien, Endotheliopathien und Mitochondropathien. Anschließend werden das Alkoholdelir und die Wernicke-Enzephalopathie erörtert. Bei zahlreichen akuten Erkrankungen von Gehirn, Rückenmark und peripherem Nervensystem treten typische Störungen vegetativer Systeme auf, deren Erkennung und Therapie insbesondere bei Intensivpatienten eine vitale Bedeutung haben kann: die autonomen Störungen. Bei der zentralen pontinen Myelinolyse kommt es zu einer akuten, vorwiegend fokal-symmetrischen Demyelinisierung im Hirnparenchym. Auch Basalganglienerkrankungen können intensivmedizinisch relevant werden. Und schließlich wird die akute Stressreaktion betrachtet, die aufgrund der vielfältigen metabolischen und endokrinen Veränderungen bei kritischen Erkrankungen entsteht. Gerade das RCVS als neuere Krankheitsentität und wichtige Differenzialdiagnose zur Vaskulitis des ZNS verdient einen eigenen Platz, in diesem Unterkapitel werden ebenfalls verwandte Syndrome wie die hypertensive Enzephalopathie und das PRES abgehandelt.

Rearranged JC virus noncoding control regions found in progressive multifocal leukoencephalopathy patient samples increase virus early gene expression and replication rate

Polyomavirus JC (JCV) infects ∼ 60% of the general population, followed by asymptomatic urinary shedding in ∼ 20%. In patients with pronounced immunodeficiency, including HIV/AIDS, JCV can cause progressive multifocal leukoencephalopathy (PML), a devastating brain disease of high mortality. While JCV in the urine of healthy people has a linear noncoding control region called the archetype NCCR (at-NCCR), JCV in brain and cerebrospinal fluid (CSF) of PML patients bear rearranged NCCRs (rr-NCCRs). Although JCV NCCR rearrangements are deemed pathognomonic for PML, their role as a viral determinant is unclear. We sequenced JCV NCCRs found in CSF of eight HIV/AIDS patients newly diagnosed with PML and analyzed their effect on early and late gene expression using a bidirectional reporter vector recapitulating the circular polyomavirus early and late gene organization. The rr-NCCR sequences were highly diverse, but all increased viral early reporter gene expression in progenitor-derived astrocytes, glia-derived cells, and human kidney compared to the expression levels with the at-NCCR. The expression of simian virus 40 (SV40) large T antigen or HIV Tat expression in trans was associated with a strong increase of at-NCCR-controlled early gene expression, while rr-NCCRs were less responsive. The insertion of rr-NCCRs into the JCV genome backbone revealed higher viral replication rates for rr-NCCR compared to those of the at-NCCR JCV in human progenitor-derived astrocytes or glia cells, which was abrogated in SV40 large T-expressing COS-7 cells. We conclude that naturally occurring JCV rr-NCCR variants from PML patients confer increased early gene expression and higher replication rates compared to those of at-NCCR JCV and thereby increase cytopathology.

Metabolische Störungen

Bei fortgeschrittenem Organversagen von Niere, Herz, Leber oder Lunge stellt eine Organtransplantation meist das einzige kurative Therapieverfahren dar. Auch eine Knochenmarktransplantation wird bei sonst unheilbaren Leukämien oder Lymphomen eingesetzt. Nach Organtransplantation treten bei 30–60% der Patienten neurologische Komplikationen auf. Differenzialdiagnostisch müssen vorbestehende, durch die Grunderkrankung bedingte, Störungen von intraoperativen Komplikationen, von metabolisch bedingten neurologischen Störungen und von Nebenwirkungen der notwendigen immunsuppressiven Medikation abgegrenzt werden. Immunsuppressiva können dabei sowohl eine direkte Neurotoxizität als auch indirekt vermehrt Infektionen des Zentralnervensystems (ZNS) und sekundäre ZNS-Malignome verursachen. Während metabolische Enzephalopathien oder opportunistische ZNS-Infektionen bei allen Patienten nach Transplantation etwa gleich häufig auftreten können, sind andere neurologische Syndrome für bestimmte Organtransplantationen typisch.

Progressive multifocal leukoencephalopathy developing in advanced pulmonal sarcoidosis

Coincidence of pulmonal sarcoidosis and progressive multifocal leukoencephalopathy (PML) rarely occurs. So far an entire course has been recorded in only very few cases. We demonstrate the case of a 49-year-old male developing an infratentorial localized PML in the setting of advanced pulmonal sarcoidosis. PML was not included in the diagnostic considerations in the first instance. Regarding the diagnosis of pulmonal sarcoidosis proved by lung biopsy, the neurological impairment was first thought to be due to a neurosarcoidosis. But magnetic resonance tomography (MRI) clearly showed a demyelination process in the cerebellum. Because of the inconsistency of the radiological findings with a neurosarcoidosis the diagnosis of an acute disseminated encephalomyelitis (ADEM) was favoured. Therefore, the patient was initially treated with corticosteroids. Because of increasing deterioration further diagnostic testings were performed. In the cerebrospinal fluid (CSF) as well as in the paraffin-embedded tissue of a stereotactical brain biopsy JCV-DNA was successfully demonstrated by PCR. Cidofovir was administered. The progression of the disease could not be influenced. The patient died 5 months after the first neurological symptoms. This report stresses the diagnostic difficulties considering patients with sarcoidosis and neurological symptoms.