Interferon alpha treatment of patients with impaired interferon gamma signaling.

Patients with deficiency in the interferon gamma receptor (IFN-γR) are unable to respond properly to IFN-γ and develop severe infections with nontuberculous mycobacteria (NTM). IFN-γ and IFN-α are known to signal through STAT1 and activate many downstream effector genes in common. Therefore, we added IFN-α for treatment of patients with disseminated mycobacterial disease in an effort to complement their IFN-γ signaling defect. We treated four patients with IFN-γR deficiency with adjunctive IFN-α therapy in addition to best available antimicrobial therapy, with or without IFN-γ, depending on the defect. During IFN-α treatment, ex vivo induction of IFN target genes was detected. In addition, IFN-α driven gene expression in patients' cells and mycobacteria induced cytokine response were observed in vitro. Clinical responses varied in these patients. IFN-α therapy was associated with either improvement or stabilization of disease. In no case was disease exacerbated. In patients with profoundly impaired IFN-γ signaling who have refractory infections, IFN-α may have adjunctive anti-mycobacterial effects.

Corneal abrasion associated with contact lens correction of keratoconus--a retrospective study.

BACKGROUND: Corneal abrasion is a frequently encountered complication of contact lens wear, but we are not aware of any previous study of relative frequency comparing keratoconic to nonkeratoconic patients. METHODS: We retrospectively studied the incidence of corneal abrasion during 2 months of contact lens practice. RESULTS: 784 contact lens-related patient visits (494 total patients); patients were assessed by 3 optometrists and 13 abrasions (11 patients) were diagnosed. Only the total number of individual patients and the first abrasion for each patient were statistically considered; the overall frequency of abrasion was therefore 11/494 (2.3%)/2 months. The frequency of abrasion was 5/68 (7.4%)/2 months for keratoconic patients and 6/426 (1.4%)/2 months for nonkeratoconic patients and this difference was significant (chi 2 test: p < 0.01). Among nonkeratoconic patients, the frequency of abrasion was 2/246 (0.8%)/2 months with hydrogel contact lens wear and 4/178 (2.2%)/2 months with rigid gas permeable (RGP) contact lens wear, but this difference did not achieve significance (chi 2 test: p = 0.10). IDENTIFIED RISK FACTORS INCLUDED: Contact lens wear; a torn lens and chemical keratitis for hydrogel lens wearers; an adherent "bound" lens and keratoconus for rigid lens wearers. CONCLUSION: Keratoconus appears to be a statistically significant risk factor for corneal abrasion among contact lens wearers.

The pH of aerosol saline solution.

We evaluated the pH of eight brands of aerosol saline solution to determine if there is a change in pH during the normal usage of an aerosol canister. The pH measurements were taken over a period of 14 to 24 days with a Corning model 10 pH meter (accuracy +/- 0.05 pH units). The saline was expelled and measured daily in 15-ml increments, the approximate volume used each day by soft lens wearers. We found no significant change in pH within each brand evaluated over the test period. However, there was a statistically significant difference in the median pH of the buffered and the unbuffered aerosol saline solutions. The mean pH of the buffered aerosol saline solutions, which averaged 7.30 pH units, was within the ocular comfort range. The mean pH of the unbuffered aerosol saline solutions, which averaged 5.79 pH units, was outside the ocular comfort range. This indicates that all aerosol saline solutions should be buffered.