IgG4-related disease in Italy: clinical features and outcomes of a large cohort of patients.

OBJECTIVES: To describe the clinical features, treatment response, and follow-up of a large cohort of Italian patients with immunoglobulin (Ig)G4-related disease (IgG4-RD) referred to a single tertiary care centre. METHOD: Clinical, laboratory, histological, and imaging features were retrospectively reviewed. IgG4-RD was classified as 'definite' or 'possible' according to international consensus guidelines and comprehensive diagnostic criteria for IgG4-RD. Disease activity was assessed by means of the IgG4-RD Responder Index (IgG4-RD RI). RESULTS: Forty-one patients (15 females, 26 males) were included in this study: 26 with 'definite' IgG4-RD and 15 with 'possible' IgG4-RD. The median age at diagnosis was 62 years. The median follow-up was 36 months (IQR 24-51). A history of atopy was present in 30% of patients. The pancreas, retroperitoneum, and major salivary glands were the most frequently involved organs. Serum IgG4 levels were elevated in 68% of cases. Thirty-six patients were initially treated with glucocorticoids (GCs) to induce remission. IgG4-RD RI decreased from a median of 7.8 at baseline to 2.9 after 1 month of therapy. Relapse occurred in 19/41 patients (46%) and required additional immunosuppressive drugs to maintain long-term remission. Multiple flares occurred in a minority of patients. A single case of orbital pseudotumour did not respond to medical therapy and underwent surgical debulking. CONCLUSIONS: IgG4-RD is an elusive inflammatory disease to be considered in the differential diagnosis of isolated or multiple tumefactive lesions. Long-term disease control can be achieved with corticosteroids and immunosuppressive drugs in the majority of cases.

Immunoglobulins in chronic inflammatory demyelinating polyneuropathy.

This article reviews the efficacy and tolerability of intravenous immunoglobulins (IVIg) in chronic inflammatory demyelinating polyradiculoneuropathy (CIDP), including those forms associated with monoclonal gammopathy (paraproteinemic demyelinating neuropathy, PDN). Class I trials demonstrated that IVIg are effective in CIDP. About two-thirds of patients respond to initial treatment; however, most of them require repeated drug doses to maintain improvement. For PDN there are some evidences that IVIg are efficacious; however, it seems that less than 50% of the patients respond to this treatment and the persistence of the response over time has not been thoroughly investigated. The safety profile of immunoglobulins is generally good; however, the possibility of the occurrence of serious adverse effects should always be considered before starting treatment.

Degeneration of cone photoreceptors induced by expression of the Mas1 protooncogene.

Although transgenic expression of oncogenes typically leads to tumorigenesis, oncogene expression directed to the rod photoreceptors leads to cell death without tumor formation. To evaluate the cellular and functional changes induced in cone photoreceptors by an oncogene, the Mas1 protooncogene was targeted to the cones of transgenic mice by the human red/green opsin promoter. Mas1 was chosen because of its exclusive expression in the nervous system and its homology to opsin. The overall histologic appearance of the transgenic retina was normal and retinal tumors were never observed. While rod-mediated electroretinograms were normal in all respects, cone-mediated responses were diminished in direct relationship to the level of transgene expression as determined by Northern blot analysis. Responses of UV- and green-sensitive cones were reduced equivalently, and Northern analysis and immunocytochemistry indicated that cone photoreceptor densities were markedly diminished throughout transgenic retinas. These results indicate that oncogene expression in cones induces cell death without tumor formation and support the possibility that aberrant oncogene expression may underlie some forms of hereditary retinal diseases. The Mas1 transgenic mice may be useful in understanding the cone photoreceptor degeneration that occurs in cone dystrophies and age-related macular degeneration and in evaluating potential therapies for these disorders.

Treatment of chronic inflammatory demyelinating polyneuropathy.

The management of chronic inflammatory demyelinating polyradiculoneuropathy (CIDP) is the main topic of this review. A few comments will also be made about treatment of the demyelinating form of paraproteinaemic demyelinating polyneuropathy (PDN) and of multifocal motor neuropathy (MMN). The review briefly describes the main characteristics of these neuropathies, and examines case series and trials which evaluated the principal therapeutic strategies for CIDP, PDN and MMN, such as intravenous immunoglobulin (IVIg) therapy, steroid treatment, plasma exchange and immunosuppressor administration. Controlled trials demonstrated that IVIg, steroid treatment and plasma exchange are effective in CIDP. For PDN the therapeutic strategies are the same as for idiopathic CIDP, but usually the clinical response is poorer. For MMN, IVIg therapy is definitely the first choice treatment.

FFT approximation in Alzheimer's disease.

The electroencephalographic modifications that occur during the course of Alzheimer's disease are characterised by an increase in the potential of low frequency bands, a diminution in the potential of alpha activity, and a change in the topographical distribution of the potential of all band frequencies. In this study, the fast Fourier transform (FFT) approximation was used to characterise modifications in the electroencephalogram location or orientation of the source of the dipole equivalent of the delta, theta, alpha1, alpha2, beta1 and beta2 frequencies in 20 with patients with Alzheimer's disease and in a control group of 20 age-matched subjects. A statistical (t-test) comparison of the two groups revealed a significant change in the location of the dipolar source along the vertical axis in 18 (90%) of the patients; this change involved all the frequency bands. There was also a significant movement of the dipolar source of the alpha1 band towards the anterior regions. In addition, the control group showed that there was a significant correlation between age and a more surface expression of the source of the delta, theta, alpha1 and beta1 bands.

Functional consequences of oncogene-induced horizontal cell degeneration in the retinas of transgenic mice.

Visual function was evaluated in transgenic mice expressing the simian virus 40 early region under the control of the promoter for phenylethanolamine-N-methyltransferase. These transgenic mice undergo a degeneration of the retinal horizontal cells and the outer plexiform layer. Electroretinograms (ERGs) were recorded under stimulus conditions chosen to elicit both receptoral and postreceptoral responses. The dark-adapted a-waves obtained from transgenic mice were not different from control recordings, indicating that the degenerative process does not interfere with function of the rod photoreceptors. In comparison, the ERG b-wave was markedly reduced in transgenic mice under both dark- and light-adapted conditions. Reproducible visual evoked potentials (VEPs) were recorded from transgenic mice in response to both low luminance stimuli that isolate rod function, and to higher luminance stimuli, indicating that retinal activity is transmitted centrally to the visual cortex. However, VEPs were delayed at all stimulus luminances compared to controls. Analysis of luminance-response functions suggests that the VEP delays could reflect the combination of a decrease in synaptic efficacy and an overall loss in visual sensitivity. These functional abnormalities correlate well with the anatomical abnormalities that have been previously observed in the transgenic retina (Hammang et al., 1993), namely a reduced number of synapses between photoreceptors and second-order neurons.

An electrophysiological metric of activity within the ON- and OFF-pathways in humans.

Several animal studies have shown an anatomical and functional separation between the ON- and OFF-pathways in the retina and in the lateral geniculate nucleus. Psychophysical studies in humans have also documented separate pathways that process increments and decrements of light. However, at the level of the visual cortex, there is electrophysiological evidence of interactions between the ON- and OFF-pathways. In addition, psychophysical studies have shown that these pathways can exhibit differential sensitivity and be differentially adapted. These findings motivated an electrophysiological study to gather further evidence of processing within the ON- and OFF-pathways in the human visual system. Using sawtooth stimulus modulation, we measured the visual evoked potential (VEP) before and after adaptation to both rapid-on and rapid-off sawtooth stimuli. The effect of adaptation was determined by comparing the VEP response in three test conditions: without adaptation, after adaptation to the same sawtooth polarity, and after adaptation to the opposite sawtooth polarity. The results reveal a selective adaptation effect, which provides physiological evidence for separate processing of increments and decrements in the human visual system. We conclude that with appropriate stimulus parameters, the VEP can serve as an objective measure of processing within the ON- and OFF-pathways in humans.