Cutaneous Coinfection of Cytomegalovirus and Mycobacterium chelonae Accelerated by Immunosuppression

A mildly diabetic 58-year-old male had traumatic ulceration on the left popliteal fossa, and the lesion progressed to a painful 6 cm deep ulcer. After surgical debridement and skin grafting, ulceration recurred. Pyoderma gangrenosum was clinically diagnosed after the first biopsy, indicating a noninfective ulcer. Immunosuppressive therapy (prednisolone and cyclosporine A) induced complete epithelialization in three months. Four months later, subcutaneous nonulcerated nodules appeared on the anterior area of the left lower leg. Subcutaneous induration progressed and ulceration recurred, so that immunosuppressive therapy continued for one year. Cytomegalovirus (CMV) viremia was detected, and the second biopsy demonstrated CMV inclusions of endothelial and perivascular cells in fibrosing septolobular panniculitis. Cyclosporine A was cancelled, prednisolone was tapered, and ganciclovir started. Viremia soon disappeared, but the lesion progressed to large induration with multiple ulcers measuring up to 3 cm. The third biopsy disclosed infection of Gram-positive mycobacteria, accompanying fat droplet-centered suppurative granulomas without CMV infection. Microbial culture identified Mycobacterium chelonae. Clarithromycin with thermotherapy was effective. A review of the second biopsy confirmed coinfection of CMV and Gram-positive mycobacteria. Immunostaining using a panel of anti-bacterial antibodies visualized the mycobacteria in the lesion. Positive findings were obtained with antibodies to Bacillus Calmette-Guérin, Bacillus cereus, MPT64 (Mycobacterium tuberculosis-specific 24 kDa secretory antigen), LAM (Mycobacterium tuberculosis-related lipoarabinomannan), and PAB (Propionibacterium acnes-specific lipoteichoic acid).

Use of a Latent Class Analysis in the diagnosis of chronic Chagas disease in the Washington Metropolitan area

Background The diversity of individuals at risk for Trypanosoma cruzi infection in the U.S. poses challenges for diagnosis. We evaluated the diagnostic accuracy of FDA-cleared tests in the Washington Metropolitan area (WMA). Methods 1514 individuals living were evaluated (1078 from Mexico, Central and northern South America [TcI-predominant areas], and 436 from southern South America [TcII/V/VI-predominant areas]). OD values from the Hemagen EIA and Chagatest v.3 Wiener, and categorical results of the IgG-TESA-blot (Western Blot with Trypomastigote Excretory-Secretory Antigen), and the Chagas Detect Plus (CDP), as well as information of area of origin were used to determine T. cruzi serostatus using Latent Class Analysis. Results We detected two latent class (LC) of seropositives with low (LC1) and high (LC2) antibody levels. A significantly lower number of seropositives were detected by the Wiener, IgG-TESA-blot, and CDP in LC1 (60.6%, p<0.001, 93.1%, p=0.014, and 84.9%, p=0.002, respectively) as compared to LC2 (100%, 100%, and 98.2%, respectively). LC1 was the main type of seropositives in TcI-predominant areas, representing 65.0% of all seropositives as opposed to 22.8% in TcII/V/VI-predominant areas. The highest sensitivity was observed for the Hemagen (100%, 95% CI: 96.2-100.0), but this test has a low specificity (90.4%, 95% CI: 88.7-91.9). The best balance between positive (90.9%, 95% CI: 83.5-95.1), and negative (99.9%, 95% CI: 99.4-99.9) predictive values was obtained with the Wiener. Conclusion Deficiencies in current FDA-cleared assays were observed. Low antibody levels are the main type of seropositives in individuals from TcI-predominant areas, the most frequent immigrant group in the U.S.

The resistance againstTrichinella spiralisinfection induced by primary infection with respiratory syncytial virus

Human infections withTrichinella spiralisand respiratory syncytial virus (RSV) are common, asT. spiralisinfections are re-emerging in various parts of the world and RSV infections remain a threat for infants. Yet, studies investigating the relationship pertaining to the two are severely lacking. In particular, immune response inductionviaRSV andT. spiralisremain largely elusive. Here, we investigated the resistance againstT. spiralisinfection induced upon primary infection with RSV. RSV, notorious for causing severe inflammatory reaction in the lungs, were intranasally infected, followed with aT. spiralisinfection in mice. Our results revealed that primary RSV infection in mice significantly raisedT. spiralis-specific and total IgE, IgG and its subclass antibody responses uponT. spiralischallenge infection (RSV-Ts). Blood eosinophil levels were decreased in RSV-Ts, accompanied with significant increase in both Th1 and Th2 cytokines. Antibodies generated against RSV in RSV-infected mice were found to react withT. spiralisexcretory/secretory antigen, showing several bands determined through immunoblotting. RSV-Ts also had a marked reduction ofT. spiralisworm burden in diaphragm. These results indicate that immune responses induced by RSV infection contribute to resistance against subsequentT. spiralisinfection.