Inflammatory arthritis can be reined in by CpG-induced DC–NK cell cross talk

Unmethylated CpG-oligodeoxynucleotides (ODNs) are generally thought of as potent adjuvants with considerable therapeutic potential to enhance immune responses against microbes and tumors. Surprisingly, certain so-called stimulatory CpG-ODNs strongly inhibited the effector phase of inflammatory arthritis in the K/BxN serum transfer system, either preventively or therapeutically. Also unexpected was that the inhibitory influence did not depend on the adaptive immune system cells mobilized in an immunostimulatory context. Instead, they relied on cells of the innate immune system, specifically on cross talk between CD8α+ dendritic cells and natural killer cells, resulting in suppression of neutrophil recruitment to the joint, orchestrated through interleukin-12 and interferon-γ. These findings highlight potential applications of CpG-ODNs and downstream molecules as antiinflammatory agents

Long-term survival in a patient with progressive multifocal leukoencephalopathy after therapy with rituximab, fludarabine and cyclophosphamide for chronic lymphocytic leukemia

A 50-year-old male with chronic lymphocytic leukemia (CLL) was treated with fludarabine, cyclophosphamide and rituximab, which produced a complete remission. Eight months after the last dose of rituximab he had visual disturbance, diminished muscular strength in the right arm and vesicular-papular lesions in the left ophthalmic branch region of the V cranial nerve. These were initially interpreted as herpes virus encephalopathy (HVE), but brain magnetic resonance imaging (MRI) showed evidence of demyelination consistent with progressive multifocal leukoencephalopathy (PML). Cerebrospinal fluid (CSF) analysis was negative for varicella zoster virus (VZV) and John Cunningham virus (JCV) DNA. The clinical suggestion of PML prompted us to perform a brain biopsy and to start treatment with mefloquine. In the brain biopsy, histopathological features of demyelination were described and the polymerase chain reaction (PCR) identified JCV, confirming the diagnosis of PML. Treatment with mefloquine (250 mg/week) and dexamethasone (4 mg/day) was started and maintained for 6 months. A year later there was an almost complete resolution of the MRI lesions and the patient achieved a stable clinical state with persisting motor impairment and severe epilepsy. The patient is alive 38 months after diagnosis of PML, which is the longest known survival to date