Long-Term Surgical Outcomes and Possible Postoperative Complication with Severe Corneal Endothelial Cell Loss After Trabeculectomy for Cytomegalovirus-Associated Anterior Uveitis with Secondary Glaucoma

PURPOSE

We assess long-term surgical outcomes after an initial trabeculectomy for cytomegalovirus-associated anterior uveitis with secondary glaucoma (CMV-SG).

METHODS

We retrospectively reviewed the medical records of 16 eyes of 15 patients with CMV-SG and 157 eyes of 157 patients with primary open-angle glaucoma. The average follow-up period was approximately 3 years. Surgical success was defined as intraocular pressure (IOP) below 18 mmHg and at least 20% lower than baseline.

RESULTS

Kaplan-Meier survival analysis revealed that bleb survival rates were not significantly different in the CMV-SG and POAG groups (P = 0.75). Bullous keratopathy occurred in 2 of 16 eyes with CMV-SG postoperatively but did not occur in the POAG group. The corneal endothelial cell density decreased by 34.2 ± 22.7% in the CMV-SG group during an average follow-up period of 2.7 ± 2.0 years.

CONCLUSION

Trabeculectomy effectively controlled IOP in CMV-SG, but attention must be paid to corneal endothelial cell loss.

Ripasudil Eyedrops Ameliorated Bullous Keratopathy Complicated with Cytomegalovirus Corneal Endotheliitis: A Case Report

PURPOSE

We describe a case of bullous keratopathy complicated with cytomegalovirus (CMV) corneal endotheliitis that was successfully treated with ripasudil eye drops.

METHODS

A retrospective case report.

RESULTS

A 65-year-old female patient diagnosed with CMV-associated anterior uveitis in the right eye was referred to us when anterior uveitis recurred with bullous keratopathy. Initial best-corrected visual acuity (BCVA) was 0.4 (decimal visual acuity). Her condition did not improve with anti-CMV treatment, and BCVA decreased to 0.07. At this point, intraocular pressure (IOP) was 20 mmHg, and ripasudil eye drops were started for IOP control. After 1 month, not only had IOP decreased to 14 mm Hg but the condition of the corneal edema had also improved. The central corneal thickness decreased to a normal level, and the BCVA recovered to 0.8.

CONCLUSION

Ripasudil eye drops not only lower IOP in patients with CMV corneal endotheliitis but may also have the potential to treat bullous keratopathy.

A Rare Case of Fungal Keratitis Caused by Plectosphaerella cucumerina Diagnosed With Repeated Corneal Scrapings: A Case Report

Plectosphaerella cucumerina is a filamentous fungus that infects plants and crops, but there are few previous reports of human infections. The current case was an 82-year-old woman who was referred to us for corneal infection in her left eye that did not improve with antibacterial and anti-inflammatory treatment. The best-corrected visual acuity (BCVA) of the eye at the first visit to us was hand motion. Slit-lamp examination revealed extensive white infiltration and ulceration in the anterior corneal stroma of the left eye. Intensive antibacterial and antiviral treatment for one month did not improve the condition of the cornea. Although initial culture testing and polymerase chain reaction (PCR) testing of corneal scraping samples did not reveal the causative microorganism, repeated culture testing identified P. cucumerina. The corneal infection eventually subsided after topical and systemic treatment with voriconazole (VRCZ). The final BCVA in the left eye was 1.3 logMAR. This was a rare case of fungal keratitis due to P. cucumerina. Our case suggests that it is important to perform repeated examinations with corneal scrapings, especially when the treatment response is poor.

Polypoidal choroidal vasculopathy in a case of retinitis pigmentosa, successfully treated with intravitreal aflibercept

Purpose

Polypoidal choroidal vasculopathy (PCV) is a subtype of age-related macular degeneration that is seen frequently in Asians. Nevertheless, it is rare for this condition to be combined with retinitis pigmentosa (RP). The purpose of this paper is to present findings from this rare combination in a Japanese patient, and to describe its successful treatment with intravitreal aflibercept (IVA).

Observations

The patient was a 71-year-old Japanese woman with RP (diagnosed at the age of 30) and PCV. She noticed a decrease in vision in her right eye 6 months previously. Decimal best-corrected visual acuity (BCVA) was 0.05 in her right eye. Optical coherence tomography and indocyanine green angiography (IA) revealed serous retinal detachment (SRD) and PCV in her right eye. The SRD was initially resolved after 3 monthly treatments with IVA, but recurrences began 5 months later, requiring four more treatments with IVA, performed about every 4 months within the next 12 months, for successful resolution. There were no recurrences of PCV in 7 more months of follow-up, as confirmed with IA at the final appointment. Final decimal BCVA in the right eye improved to 0.15. Furthermore, macular retinal sensitivity, measured with microperimetry, increased after the treatment, and RP-related visual field narrowing, determined by Goldmann perimetry, did not progress throughout follow up of 26 months.

Conclusion

More than 2 years of follow up showed that IVA may be effective for treating PCV, even in RP patients, and can increase central visual function without causing progression of RP-related visual field narrowing.

Carotid artery intima-media thickness, HDL cholesterol levels, and gender associated with poor visual acuity in patients with branch retinal artery occlusion

PURPOSE

To investigate factors associated with poor visual acuity (VA) in branch retinal artery occlusion (BRAO).

METHODS

This was a retrospective cross-sectional study of 72 eyes with BRAO of 72 patients. For statistical comparison, we divided the patients into worse-VA (decimal VA < 0.5) and better-VA (decimal VA > = 0.5) groups. We examined the association of clinical findings, including blood biochemical test data and carotid artery ultrasound parameters, with poor VA.

RESULTS

Median age, hematocrit, hemoglobin and high-density lipoprotein (HDL) differed significantly between the groups (P = 0.018, P < 0.01, P < 0.01, and P = 0.025). There was a tendency towards higher median IMT-Bmax in the worse-VA group (worse-VA vs. better-VA: 2.70 mm vs. 1.60 mm, P = 0.152). Spearman's rank correlation test revealed that logMAR VA was significantly correlated to IMT-Bmax (rs = 0.31, P < 0.01) and IMT-Cmax (rs = 0.24, P = 0.035). Furthermore, logMAR VA was significantly correlated to HDL level (rs = -0.33, P < 0.01). Multivariate logistic regression analysis revealed that IMT-Bmax (odds ratio [OR] = 2.70, P = 0.049), HDL level (OR = 0.91, P = 0.032), and female gender (OR = 15.63, P = 0.032) were independently associated with worse VA in BRAO.

CONCLUSIONS

We found that increased IMT-Bmax, decreased HDL, and female sex were associated with poor VA in BRAO patients. Our findings might suggest novel risk factors for visual dysfunction in BRAO and may provide new insights into the pathomechanisms underlying BRAO.

Concomitant herpes simplex keratitis and autoimmune-associated ulcerative keratitis in rheumatoid arthritis patients

Purpose

To describe four cases of concomitant herpes simplex keratitis (HSK) and autoimmune-associated ulcerative keratitis (UK) in patients with rheumatoid arthritis (RA).

Observations

All patients developed HSK and UK while undergoing treatment for RA. The average age of onset for RA, UK and HSK was 49.3, 69.5 and 70.5 years, respectively. UK preceded HSK in three cases and followed HSK in one case. Two patients had bilateral UK and two had unilateral UK. HSK was unilateral in all cases. All the cases had been treated with immunosuppressive agents including steroid, methotrexate, calcineurin inhibitors, etanercept and tocilizumab at the onset of HSK. Every patient was treated for HSK with topical acyclovir ointment combined with oral valacyclovir. The final visual outcome was extremely poor despite intensive therapy.

Conclusions and Importance

These cases raise the possibility that RA patients have an increased risk of HSK, and that HSK may tend to be severe in these patients because of their immunocompromised condition. Furthermore, the complication of HSK and UK in RA patients is difficult to treat because of the atypical clinical manifestation. Thus, the emergence of corneal ulcer, especially in patients with a long clinical history of RA, calls for careful follow-up.

Diagnosing superinfection keratitis with multiplex polymerase chain reaction

PURPOSE

To report the potential usefulness of multiplex polymerase chain reaction (mPCR) for diagnosing superinfection keratitis caused by herpes simplex virus-1 (HSV-1), bacteria and fungus.

METHODS

Case series. Corneal scrapings were analyzed with mPCR for human herpes virus 1-8, bacterial 16S ribosomal DNA (rDNA) and fungal 28S rDNA.

RESULTS

Case 1 was a 69-year-old man who presented with refractory infectious keratitis. PCR examination was positive for bacterial 16S rDNA and negative for fungal 28S rDNA. HSV-1 was not examined at this time. A geographic ulcer arose after 2 months of intensive antibacterial treatment. Herpes simplex keratitis (HSK) was suspected; PCR analysis was positive for HSV-1. Corneal scrapings obtained at the initial visit were re-analyzed and found to be HSV-1 positive. Thus, it turned out that this was a case of superinfection keratitis caused by bacteria and HSV-1. Case 2 was a 60-year-old man with corneal ulcer who had received unsuccessful treatment with antibiotics. mPCR analysis was positive for HSV-1, bacterial 16S rDNA and fungal 28S rDNA. The patient was diagnosed with superinfection keratitis caused by HSV-1, bacteria and fungus. Case 3 was an 82-year-old woman who had been treated for HSK and then developed bacterial keratitis during treatment. mPCR analysis was positive for HSV-1 and bacterial 16S rDNA. The patient was diagnosed with superinfection keratitis caused by HSV-1 and bacteria.

CONCLUSION

Superinfection keratitis is hard to diagnose because of its atypical manifestation. mPCR has the potential to allow prompt diagnosis and appropriate treatment in these cases.

Multiplex polymerase chain reaction for pathogen detection in donor/recipient corneal transplant tissue and donor storage solution

Corneal transplantation is a safe, reliable method of restoring visual acuity in patients with corneal disorders. Although it has a very high success rate, rejection can still occur, especially if the site is infected. Therefore, seeking to find better ways to manage infection risk, this study investigated a new technique, based on multiplex polymerase chain reaction (mPCR), to identify pathogens, including viruses, bacteria, and fungi, in corneal transplantation recipient sites, donor corneas and the donor cornea storage solution. The subjects comprised 50 patients who underwent corneal transplantation at Tohoku University Hospital between July 2014 and April 2015. We obtained extracted (recipient) cornea samples in 37 cases, donor cornea samples in 50 cases, and corneal storage solution samples in 50 cases (18 of these 50 samples contained DNA). Herpes simplex virus type 1 DNA was detected in four recipient corneas, Parvovirus B19 DNA was detected in two recipient corneas, Human herpes virus type 6 was detected in two donor corneas, and Aspergillus DNA was detected in one corneal storage solution sample. Thus, mPCR successfully identified pathogenic DNA in corneal tissues and storage solution, suggesting that evaluation with mPCR may improve the ability to predict the risk of infection after corneal transplantation.

Twenty-nine-gauge dual-chandelier retroillumination for the non-open-sky continuous curvilinear capsulorhexis in the penetrating keratoplasty triple procedure

We describe a technique for the penetrating keratoplasty (PKP) triple procedure that uses 29-gauge dual-chandelier illumination during creation of a non-open-sky continuous curvilinear capsulorhexis (CCC). The chandeliers are inserted through the pars plana into the vitreous cavity through the bulbar conjunctiva at the 3 o'clock and 9 o'clock positions. We compared this approach with that of a core vitrectomy, in which a single 25-gauge port is inserted into the vitreous cavity transconjunctivally through the upper temporal pars plana. The area of halation around the corneal opacity was significantly smaller in the 29-gauge group than in the 25-gauge group. The reduction in halation improved visibility of the anterior capsule and enabled the surgeon to perform CCC with greater safety. The 29-gauge chandelier system was more suitable than the 25-gauge chandelier system for the non-open-sky CCC component of the PKP triple procedure.

[Indices of Visual Improvement after Conservative Treatment for Branch Retinal Vein Occlusion with Macular Edema]

Purpose: To identify indices of visual improvement after conservative treatment for branch retinal vein occlusion (BRVO) with macular edema. Methods: We retrospectively reviewed the charts of 33 eyes of 33 patients with BRVO with macular edema. Inclusion criteria were 1) onset within 4 months, 2) decimal visual acuity of 0.05 to 0.5, and 3) minimum central subfield thickness (CST) of 250 μm. After 3 months of treatment with oral aspirin and kallidinogenase, the patients were divided into two groups: those with logarithmic minimum angle of resolution (logMAR) visual improvement of 0.3 or more (14 eyes) and less than 0.3 (19 eyes). We then compared systemic and ocular findings in the groups. Results: The groups differed significantly in logMAR improvement after 1 month (p<0.01) and in CST change after 1 month (p<0.05). Multiple logistic regression analysis showed that CST change after 1 month was a significant index of visual improvement (p<0.05). The cutoff value for visual improvement was -30 μm (sensitivity: 78.6, specificity: 68.4, positive predictive value: 64.7, negative predictive value: 81.3). Conclusion: A decrease in CST of more than 30 μm 1 month after conservative treatment indicates that visual acuity is likely to be improved after 3 months.

Two percent ethylenediaminetetraacetic acid chelation treatment for band-shaped keratopathy, without blunt scratching after removal of the corneal epithelium

Background

The purpose of this study was to assess the effectiveness of 2% ethylenediaminetetraacetic acid (EDTA) for the treatment of band-shaped keratopathy.

Methods

We studied 24 eyes of 16 patients with band-shaped keratopathy who underwent EDTA chelation treatment from April 1, 2011 to December 31, 2012. We compared preoperative and 1 month postoperative logarithm of the minimum angle of resolution (logMAR) best corrected visual acuity, intraocular pressure, and corneal curvature radius (K1, horizontal meridian; K2, vertical meridian; Km, average of K1 and K2). The Mann-Whitney U-test was used to determine the significance of differences.

Results

There was a significant difference in preoperative and postoperative logMAR best corrected visual acuity (P=0.01). There were no significant differences in preoperative and postoperative intraocular pressure (P=0.24) or corneal curvature radius (K1, P=0.54; K2, P=0.49; Km, P=0.45).

Conclusion

After 2% EDTA chelation treatment, post-operative logMAR best corrected visual acuity improved significantly. Moreover, since there was no significant difference in corneal curvature radius, there was little influence on corneal surface form. We believe that the results of our 2% EDTA chelation treatment were comparable with results obtained with 3.75% EDTA chelation treatment in previous reports. Two percent EDTA chelation is an effective treatment for band-shaped keratopathy and a useful method for any institution.

Difficulty in inserting 25- and 23-gauge trocar cannula during vitrectomy

PURPOSE

To determine the incidence of difficulty in inserting a 25- and 23-gauge trocar cannula (DITC) during 25- or 23-gauge micro-incision vitrectomy surgery (MIVS).

METHODS

Retrospective, consecutive, interventional case series performed by a single surgeon at a single centre. We defined a DITC as the condition where at least 1 trocar cannula could not be inserted into the vitreous at the beginning of MIVS. The incidence of DITC was calculated from 1,525 eyes, and the pre-operative demographics of the DITC cases were compared to those of the non-DITC cases.

RESULTS

The incidence of DITC for all cases was 0.6% (9 of 1,525 eyes). Overall, there were 242 eyes with a retinal detachment (RD), and 8 of the 9 eyes with DITC had an RD with an incidence of 3.3% (8 of 242 RD eyes). Seven of these 8 eyes had a total RD, 4 also had a choroidal detachment, 4 eyes were also myopic (>-8.0 dpt, high myopia), and 6 of the 8 eyes were hypotonic (<8 mm Hg). The DITC cases had larger RDs (p<0.0001), a higher incidence of choroidal detachment (p<0.0001), higher myopia (p=0.0204) and hypotony (p=0.0003) than the non-DITC eyes with an RD.

CONCLUSIONS

A large RD, a choroidal detachment, high myopia and hypotony are significant risk factors for DITC. We recommend that MIVS should be performed cautiously for eyes with these risk factors.

[A relationship between a psychosomatic and a skin condition in patients with atopic dermatitis]

Atopic dermatitis (AD) has been clinically well-known to be frequently exacerbated by some psychosomatic stress. In this study, we examined a relationship between a psychosomatic and a skin condition in patients with AD. Visual analogue scale (VAS) for the grade of general physical condition, mental stress and others were reported daily for themselves, while skin physiological parameters, resident skin bacteria and a psychological questionnaire (POMS) were measured every 2 weeks. It was observed that tense-anxious and depressive scores of POMS tended to correlate with skin conductance, a skin clinical score and a number of total skin bacteria and others. These results suggest that changes of psychosomatic condition reciprocally correlate with the exacerbation and improvement of skin symptom in patients with AD.

[A case of atopic dermatitis which showed correlation of psychological state and lesions--changes of value of psychological test, skin lesion and NK cell activity]

The relationship between psychological state and skin lesions of atopic dermatitis were investigated with a 31-year-old male patient. He had severe atopic dermatitis which became worse with psychological stress. A psychological test, profile of mood states (POMS), was performed on him every 2 weeks. Peripheral lymphocytes and natural killer (NK) cell activity were investigated at some points. When the psychological state showed more depressive, anxiety, anger, fatigue and confusion, the skin lesions became worse and recovered after the psychological states turned well. Correlation was shown between itch and stress or fatigue by a visual analogue scale (VAS) (p < 0.001). NK cell activity decreased during the worse psychological state and recovered during the near normal psychological state, although, the lymphocyte count and CD4/8 ratio in peripheral blood did not change during the study. These results suggest that some patients with atopic dermatitis should be treated psychologically in addition to standard dermatological treatment.

Regulation of the cutaneous allergic reaction by humidity

Humidity is 1 of the environmental factors which regulate skin conditions. Effects of humidity on the cutaneous immune reaction were examined. Contact hypersensitivity to 2,4,6-trinitrochlorobenzene was elicited in C57BL/6 mice. The reaction was greater in mice housed under low humidity conditions (about 10%) for 2 days, at either the induction or elicitation phase, than in mice housed under rather high humidity conditions (80%). After housing under controlled humidity for 2 days, the number of I-A positive cells was 16% higher in the epidermis exposed to the dry condition. The increased population of FITC-positive cells were in regional lymph nodes after painting of FITC during housing under lower humidity. Our study demonstrated that the cutaneous immune reaction is regulated by environmental humidity and suggested 2 possible mechanisms, i.e., increase in Langerhans cells and increased penetration of allergen with low humidity.

Antigenic characterization in ampiroxicam-induced photosensitivity using an in vivo model of contact hypersensitivity

Ampiroxicam (APX), a prodrug of piroxicam (PXM), has been reported to induce photosensitivity. Antigenic characterization of these photosensitivities, however, is still insufficient. The purpose of the present study was to elucidate further mechanism of photosenstivity induced by APX and PXM using an in vivo model of contact hypersensitivity in guinea pigs. Animals sensitized with ultraviolet-A (UVA)-irradiated 1% APX showed positive reaction in the patch testing to UVA-irradiated 1% APX and 1% thiosalicylate (TOS), while they were negative in challenge with UVA-irradiated 1% PXM, non-irradiated APX and PXM, whereas none of UVA-irradiated or non-irradiated APX and PXM showed positive patch test reaction in animals sensitized with UVA-irradiated 1% PXM or control vehicles. Animals sensitized with 1% TOS were successfully challenged by 1% TOS and cross-reacted with UVA-irradiated 1% APX; however, they failed to react with UVA-irradiated PXM, non-irradiated APX and PXM. Indeed, the in vitro study revealed that the concentration of APX was easily reduced by the increase of UVA irradiation dose, as compared with that of PXM. Interestingly, absorption spectrum of UVA-irradiated APX was similar to that of TOS, which is thought to be an active hapten of PXM. In the present study, we succeeded in the development of a novel animal model reflecting the clinical observations. Furthermore, these results suggested that contact hypersensitivity induced by UVA-irradiated APX is developed by photoproducts of APX itself, but not by the biotransformation of APX to PXM.

Quantitative polymerase chain reaction using an external control mRNA for determination of gene expression in a heterogeneous cell population

Gene expression can be evaluated quantitatively by conventional RT-PCR or Northern blotting with the aid of a correction based on the expression of an internal control gene. However, this approach is not suitable for quantitating gene expression in a group of heterogeneous cell subsets, because the internal control gene expression may vary among the subsets. Therefore, we developed a new method for quantitative PCR using rat poly(A)+ RNA as an external control. We used this method to investigate cytokine gene expression in lymph node cells from mice during the induction of contact hypersensitivity. Expression of the murine glyceraldehydephosphate dehydrogenase (GAPDH) gene, a candidate internal control, was not constant in cells from trinitrochlorobenzene- and vehicle-applied animals, suggesting that GAPDH gene expression changes in heterogeneous lymph node-cell subsets during induction of contact hypersensitivity. Therefore, we decided to use rat GAPDH mRNA as an external control. Cytokine gene expression was measured by quantitative PCR and was corrected based on external rat GAPDH cDNA. The reliability of this quantitative PCR was superior to that of the conventional method with an internal control.

Development of a non-radioactive endpoint in a modified local lymph node assay

A murine local lymph node assay (LLNA) has been developed as an alternative to guinea pig models for contact sensitization testing. Although the LLNA appears to be a little less sensitive than the most stringent of guinea pig assays, it provides a rapid, objective, quantitative and cost-effective method for screening strong contact sensitizers and has advantages with respect to animal welfare. However, a potential disadvantage is the need for the use of radioactive material. We have reported previously that an ex vivo assay based on similar principles to the original in vivo LLNA, but using a non-radioactive endopoint, was valid for the prediction of strong sensitizers. This ex vivo assay was not sensitive enough to allow prediction of moderately potent ones. In this study, we propose a new parameter, Corrected IL-2 Index (CII), for the prediction of moderate sensitizers. To obtain CII the IL-2 release in the supernatant of the cell culture is corrected for lymph node weight ratio and ratio of CD4-positive subset. We found that CII predicted the allergenicity of moderate sensitizers, including the ones recommended by the OECD in guideline 406, such as mercaptobenzothiazole and hexyl cinnamic aldehyde. The allergenicity of metal salts, such as potassium dichromate, ammonium tetrachloroplatinate and cobalt chloride, was also predicted by the CII. We conclude that the use of CII as an index significantly increases the sensitivity of the ex vivo method so that moderate sensitizers may also be detected.

A modification of the local lymph node assay for contact allergenicity screening: measurement of interleukin-2 as an alternative to radioisotope-dependent proliferation assay

The local lymph node assay is an effective prediction method for contact allergenicity, but employs radioisotopes. We investigated whether measurement of interleukin-2 (IL-2) production by lymph node cells could be used instead to predict contact allergenicity of chemicals. Test chemicals were applied for three consecutive days to both ears of Balb/c mice and the auricular lymph nodes were obtained on either the fourth or fifth day after the first application. Both IL-2 concentration in supernatant of the suspension and proliferative activity of lymph node cells were determined after 24-, 48-, 72-h cell culture in RPMI-1640 medium by ELISA and by measuring [3H]methylthymidine incorporation, respectively. These two methods detected allergenicity similarly except in the case of TNCB and oxazolone, which showed excessive proliferation-inducing capacity as compared to IL-2 release-increasing effect. Flow cytometry showed that these two chemicals also increased the percentage of Iad-positive cells in the lymph nodes, suggesting that these chemicals might induce not only cellular immunity but also humoral immunity. We conclude that interleukin-2 assay is a convenient and dependable method for screening strong contact allergens without using radioisotopes.

Gold dermatitis due to ear piercing: correlations between gold and mercury hypersensitivities

A case of allergic contact dermatitis due to gold pierced earrings is reported. The patient developed recurring redness and swelling on her earlobes a month after the wearing of pierced-type gold earrings, which was followed by the appearance of reddish nodules around the puncture marks. Patch tests revealed positive reactions to 0.1% mercuric chloride, 1% gold sodium thiomalate and 0.2% chloroauric acid. We also demonstrated that guinea pigs contact-sensitized with a mercuric compound developed positive patch test reactions to both mercuric and gold compounds. These results suggest that there may be correlations between gold and mercury hypersensitivities.

Allergenicity and tolerogenicity of amlexanox in the guinea pig

Amlexanox (AMLX), an anti-allergic agent, is available in Japan as Elics opthalmic solution, Solfa nasal douche and Solfa tablets. Cases of allergic contact dermatitis induced by Elics ophthalmic solution, which contains 0.25% AMLX, were reported within a year of its introduction. We therefore examined the contact sensitizing potency of AMLX. Guinea pigs sensitized to 0.25% AMLX exhibited a strong positive patch test reaction. Further, AMLX-sensitized animals developed rashes following oral and systemic challenge with AMLX. This animal model reflected the clinical experience of systemic contact dermatitis due to AMLX. The non-responsiveness induced by oral administration of AMLX to AMLX-induced animals was transient, and clinical prophylaxis by desensitization with oral AMLX may only increase the risk of systemic contact dermatitis. On the other hand, there have been few reports of drug eruption from oral Solfa tablets in spite of their wide use. Therefore, we also examined the induction of tolerance by oral administration of AMLX. Oral administration of AMLX before sensitization resulted in complete non-responsiveness. It seems likely that a substantial reduction in the risk of AMLX sensitization by Elics may be achieved by prior oral administration of Solfa tablets containing AMLX.

Piroxicam has at least two epitopes for contact photoallergy

We have demonstrated previously in guinea pigs that the induction of photocontact sensitivity to piroxicam (PXM) also induces a state of cross-reactive contact hypersensitivity to two compounds having structurally related elements, thimerosal (TMS) and thiosalicylate (TOS). The present study was conducted to determine whether oral administration of TOS would desensitize guinea pigs previously photosensitized with PXM. At the same time, the spectrum of reactivities against these compounds and against tenoxicam (TXM) which resembles only piroxicam was assessed by appropriate sensitizing and eliciting protocols. As expected, animals photosensitized to PXM developed reactivities against all four compounds, PXM and TXM (photosensitivity) and TMS and TOS (contact sensitivity). By contrast, photosensitization with TXM induced cross-reactivity only against PXM. Moreover, the induction of contact sensitivity against TMS or TOS induced photosensitive cross-reactivity to PXM, but not to TXM. Finally, the oral administration of TOS produced a transient desensitization only for TMS and TOS. These results suggest that photosensitization with PXM induces two distinct reactivities. The first reactivity cross-reacts with TMS and TOS and is suppressible with orally administered TOS. The second cross-reacts only with TXM and is not suppressible with oral TOS. We conclude that PXM acquires at least two distinct immunogenic epitopes when exposed to UVA irradiation.

A cross-reaction between piroxicam-photosensitivity and thiosalicylate hypersensitivity in lymphocyte proliferation test

We examined the cross-reaction between photosensitivity to piroxicam (PXM) and contact sensitivity to thiosalicylate (TOS) by a lymphocyte proliferation test (LPT) in guinea pigs. The lymph node cells (LNCs) plus peritoneal exudate cells (PECs) from guinea pigs contact-sensitized with TOS remarkably cross-proliferated to PXM under UVA (4 J/cm2) irradiation. On the other hand, the PXM-photosensitized LNCs+PECs also cross-proliferated to TOS. From these results, the reciprocal cross-reaction between TOS-hypersensitivity and PXM-photosensitivity was reconfirmed by the in vitro LPT, indirectly indicating that the PXM-photosensitivity is a cell (probably T cell)-mediated PXM photoallergy in its nature. The TOS-primed LNCs+PECs did not cross-proliferate to UVA (4 J, 180 J or 500 J/cm2)-pretreated PXM (UVA-PXM) although it is supposed to contain several photoproducts of PXM. Furthermore, the TOS-primed LNCs developed a remarkable proliferative cross-response to the PECs pulsed with PXM under UVA (4 J/cm2) irradiation (photo-PXM-modified PECs), but not to the PECs pulsed with PXM or UVA-PXM. Therefore, it is presumed that the cross-reactive molecule, which is easily formed from PXM under UVA irradiation, is unstable, and that the formation of complete antigen by the generation of this molecule and its photobinding needs the coexistence of PECs, PXM and UVA irradiation at the same time in the culture.

Photosensitivity to piroxicam is induced by sensitization to thimerosal and thiosalicylate

Piroxicam (PXM), a nonsteroidal anti-inflammatory drug, has been well known to often induce photosensitive eruptions within a few days after its administration. It has been reported that this photosensitivity correlates well with a positive patch-test reaction to thimerosal (TMS) and also to thiosalicylate (TOS), which is an active hapten of TMS. But it has not yet been concluded whether this correlation is caused by a cross-reaction among the drugs or not. In our experiments, animals contact-sensitized with TMS or TOS developed positive photopatch-test reactions to PXM, and those photocontact-sensitized with PXM had positive patch-test reactions to TMS and TOS. Photosensitive reactions were also induced by UVA irradiation (photo test) performed 90 min after perioral administration of PXM in the animals contact-sensitized with TMS or TOS. Analysis of the UVA-treated PXM by nuclear magnetic resonance spectrography and thin-layer chromatography revealed that the high dose of UVA induced photodecomposition of PXM, and generated several other chemicals different from PXM. But the PXM treated with the high dose of UVA could not induce positive patch-test reactions in many of the animals contact-sensitized with TMS or TOS. The cross-reacting hapten generated from PXM by UVA treatment may not be stable in the absence of carrier proteins. These results taken together indicate that the PXM photosensitivity in man is induced by contact-sensitization with TMS, as shown in our animal model, and then is photoallergic in nature. But the identity of the cross-reacting substance remains unknown.