IL-15 restores defective NK anti-fungal activity in a primary Hemophagocytic lymphohistiocytosis Patient (164.1)

Hemophagocytic lymphohistiocytosis (HLH) is a rare yet potentially fatal clinical syndrome caused by various congenital defects that result in defective perforin-dependent cytotoxicity of NK cells. This leads to increased T cell activation and proliferation and excessive cytokine production including IL-1, IL-6, IFN-γ, TNF-α and GM-CSF that causes sustained activation of macrophages that is manifest as extensive inflammation and tissue damage. One study showed that 50% of deaths from familial HLH were due to invasive fungal infections. We sought to investigate whether NK cells from a patient with HLH have defective anti-fungal activity and seek a potential therapeutic approach. NK cells (CD56+/CD3-) were isolated from a two-month-old boy with c1090-1091del of the perforin gene resulting in p.Leu364>Stop consistent with the FHL-2 form of HLH. Defective NK killing was observed for both Cryptococcus neoformans and Candida albicans. Remarkably, the defective anti-Candida activity of NK cells could be restored within 24 hours by IL-15 treatment that was similar to the enhanced anti-Candida activity of NK cells from healthy donors. We speculate that IL-15 enhances antifungal activity by stimulating NK cells to employ an alternate microbicidal effector mechanism. This result is the first to show that IL-15 can restore defective cytotoxic activity of NK cells from an HLH patient, and further studies might be considered to explore the mechanism and potential form of immunotherapy.

Oral fluorescein angiography with the scanning laser ophthalmoscope in diabetic retinopathy: a case controlled comparison with intravenous fluorescein angiography

AIM

To compare the performance of oral fundus fluorescein angiography with a confocal scanning laser ophthalmoscope (SLO) with intravenous fundus fluorescein angiography (IVFFA) with a fundus camera in the assessment of sight-threatening diabetic retinopathy.

PATIENTS AND METHODS

A total of 25 patients undergoing IVFFA to investigate their diabetic retinopathy were recruited. Participants returned 1 week later and an oral angiogram with the SLO was performed. Six facets of the oral and intravenous angiograms were scored and compared: visualization of the foveal avascular zone (FAZ); branch retinal identification; macular leakage; identification of microaneurysms in areas of macular leakage; peripheral nonperfusion, and leakage from neovascular complexes.

RESULTS

Compared to IVFFA, the FAZ was unreliably visualized with oral angiography (Kappa 0.1, 95% CI 0-0.3). In contrast, macular leakage (Kappa 0.78, 95%, CI 0.72-0.83), identification of microaneurysms in areas of macular leakage (Kappa 0.78, 95%, CI 0.72-0.83), and neovascular complexes (Kappa 1.0) were reliably seen. Analysis of the visualization of peripheral nonperfusion was complicated by the finding that profuse dye leakage from neovascular complexes obscured the view of the peripheral retina. If the five angiograms in which this occurred were excluded, oral angiography identified 23 of the 24 eyes in which significant nonperfusion was found on IVFFA.

CONCLUSION

Oral angiography with the SLO can provide high-quality angiograms that allow judgments to be made about the presence of treatable diabetic maculopathy, proliferative diabetic retinopathy, and peripheral nonperfusion. In the presence of coexisting macular oedema, it proved to be an unreliable technique with which to investigate foveal ischaemia.

A prospective evaluation of the Heidelberg retina flowmeter in diagnosing ischaemia following branch retinal vein occlusion: a masked, controlled comparison with fluorescein angiography

PURPOSE

To evaluate the use of the Heidelberg retina flowmeter (HRF) in diagnosing retinal ischaemia following macular branch retinal vein occlusion.

METHODS

Ten patients with ischaemic macular branch retinal vein occlusion, as determined by strict fluorescein angiographic criteria, were examined with the HRF. Blood flow, blood volume and blood velocity characteristics from areas of ischaemic and non-ischaemic retina were recorded and the results between the normal and ischaemic areas of retina compared with paired t-test analysis. Ten healthy volunteers were similarly examined and acted as a control group.

RESULTS

Compared with normal retina the HRF recorded a statistically significant reduction in blood flow within the ischaemic retina in 7 of the 10 study patients. In 2 patients the HRF actually recorded a statistically significant increase in blood flow in the area of ischaemic retina; there was no significant difference in the blood flow recorded in the normal and ischaemic retina in the remaining patient. HRF examination of the control group revealed a significant difference in the blood flow between two areas of apparently normal retina in 3 of the 10 volunteers.

CONCLUSION

The HRF is not a reliable tool for diagnosing retinal ischaemia following branch retinal vein occlusion. Our results may suggest that the HRF blood flow recordings are not derived from the retinal circulation alone, but represent the cumulative blood flow through the combined circulations of the retina and choriocapillaris.

Arterio-venous shunting and proliferating new vessels in acute painful neuropathy of rapid glycaemic control (insulin neuritis)

Insulin neuritis, or painful neuropathy following rapid improvement in glycaemic control, is well recognised but its aetiology is unclear. An understanding of the processes involved in the genesis of acute painful neuropathy of rapid glycaemic control may give an insight into the early pathogenetic factors leading to diabetic nerve damage in general. We have identified five subjects with insulin neuritis including one who developed severe autonomic neuropathy following treatment with insulin. Subjects underwent: 1) assessment of neuropathic symptom and deficit scores; 2) quantitative sensory and electrophysiological studies and 3) sural nerve epineurial vessel photography and fluorescein angiography in vivo. The sural nerve photographs were independently graded by an ophthalmologist. All subjects with insulin neuritis presented with severe sensory symptoms but clinical examination and electrophysiological tests were normal except in the subject with the severe autonomic neuropathy in whom all the tests were abnormal. On nerve photography, there was an abundance of epineurial nutrient vessels although these showed severe abnormalities including arteriolar attenuation, tortuosity and arterio-venous shunting in all subjects. Proliferating neural 'new vessels' which bear striking similarities to those found in the retina and that were more leaky to fluorescein than normal vessels, were observed in three subjects. Venous distension and/or tortuosity was also observed in three subjects and this was most marked in the subject with severe autonomic neuropathy. This study shows that epineurial nutrient vessel anatomy is abnormal in subjects with acute painful neuropathy of rapid glycaemic control, a condition previously thought to be purely metabolic in origin. The presence of epineurial arterio-venous shunting and a fine network of vessels resembling the new vessels of the retina, may lead to a 'steal' effect rendering the endoneurium ischaemic. This process may be important in the genesis of neuropathic pain, and further supports the importance of vascular factors in the pathogenesis of diabetic neuropathy.

Cerebral blood flow changes with acute cocaine intoxication: clinical correlations with SPECT, CT, and MRI

In summary, these data suggest that widespread primary or secondary cerebral vasoconstriction is common in patients with neurological complications from cocaine. In most patients, SPECT showed wide-spread hypoperfusion in regions that had no clear clinical significance (e.g., the periventricular area). In many, the SPECT was performed more than 24 hours after the onset of neurological symptomatology. These findings raise several questions. It has been assumed that these SPECT changes in patients with acute neurological symptoms are temporary, although it will be important to determine whether these areas of hypoperfusion persist after symptoms have abated. Recently, Holman and colleagues (1991) found multifocal and deep areas of hypoperfusion with SPECT in 16 of 18 patients with a history of chronic cocaine abuse. Although most of the subjects tested positive for cocaine, several had abstained from cocaine use for weeks prior to the study. All 18 subjects had neuropsychological deficits, 13 mild and 5 moderate. Similarly, Pascual-Leone and colleagues (1991) have shown that CT scan atrophy strongly correlates with the duration of cocaine abuse, suggesting that brain injury may occur with continued use of cocaine. It is the authors' concern that cocaine abuse might produce permanent changes in cerebral perfusion. In conclusion, brain SPECT was found to be a useful procedure in the evaluation of acute cocaine intoxication. Brain SPECT revealed focal cortical lesions not seen on head CT or MRI, which corresponded to clinical deficits. In addition, [99mTc]HMPAO brain SPECT had a characteristic scalloped appearance, and this may be a marker for acute intoxication with cocaine. This study further supports the contention that cocaine causes neurological disease by its vasoconstrictive action.

Impaired blood flow and arterio-venous shunting in human diabetic neuropathy: a novel technique of nerve photography and fluorescein angiography

New techniques of sural nerve photography and fluorescein angiography which are able to provide an index of nerve blood flow have been developed. Under local anaesthetic, 3 cm of sural nerve was exposed at the ankle using an operating microscope. Without disturbing the epineurium, vessels were identified and photographed at a standard magnification (x 30). These were independently graded by an ophthalmologist not otherwise involved with the study. Fluorescein angiography was then carried out on the exposed nerve. The fluorescein appearance time and intensity of fluorescence were quantified, using computer analysis of digitised images. Thirteen subjects with chronic sensory motor neuropathy, five non-neuropathic diabetic and nine normal control subjects were studied. The mean epineurial vessel pathology score of the neuropathic group was significantly higher than the combined normal control and non-neuropathic diabetic groups (p < 0.01). Direct epineurial arteriovenous shunting was observed in six neuropathic and one non-neuropathic diabetic patients and not in any of the normal control subjects. The nerve fluorescein appearance time was significantly delayed in subjects with chronic sensory motor neuropathy (51.5 +/- 12 s) compared to both normal (34.7 +/- 9 s, p < 0.01) and non-neuropathic diabetic subjects (33.4 +/- 11 s, p < 0.025). The mean intensity of fluorescence at 96, 252 and 576 s, was significantly lower in subjects with chronic sensory motor neuropathy compared with both of the other groups (p < 0.05).(ABSTRACT TRUNCATED AT 250 WORDS)

Retained intraocular foreign body simulating choroidal melanoma. A report of two cases

Many different lesions can be difficult to distinguish from malignant melanomas of the choroid. With the use of modern diagnostic facilities the misdiagnosis rate has been greatly reduced. In a recent report from the Collaborative Ocular Melanoma Study Group the incidence of misdiagnosis was only 0.48%. The presence of a retained intraocular foreign body presenting as a raised pigmented choroidal mass similar to a uveal melanoma is rare. We report two cases in which retained intraocular foreign bodies presented clinically as raised pigmented intraocular lesions. Retained intraocular foreign bodies should be considered in the differential diagnosis of ocular tumours, especially if there are any atypical features.

Haemangioma of the optic disc

Isolated capillary haemangiomata of the optic disc are uncommon; they may be associated with the von Hippel-Lindau syndrome. Renal carcinoma occurs in almost one-third of patients with this condition, and it may go unnoticed until metastases occur. Early nephrectomy offers a cure. It is important, therefore, that all patients with optic disc capillary haemangiomata as well as their relatives are referred for screening for the stigmata of this disease.