Natalie Fowlkes

Increased CXC Ligand 10 Levels and Gene Expression in Type 1 Leprosy Reactions

ABSTRACT Type 1 reaction (T1R) is a systemic inflammatory syndrome causing substantial morbidity in leprosy. T1R results from spontaneously enhanced cellular immunity in borderline types of leprosy, but there are no established laboratory markers for the reaction. Preliminary studies have identified elevated circulating CXC ligand 10 (CXCL10) during T1R. Correlation of CXCL10 with clinical T1R was studied in repeated serum specimens obtained before, during, and after T1R. CXCL10 gene expression was assessed in biopsy specimens taken before and during T1R, and sections were stained for the cytokine using monoclonal antibodies. Sequential serum specimens revealed elevation of circulating CXCL10 associated with episodes of T1R (P = 0.0001) but no evidence of an earlier, predictive change in the level of the chemokine. Reverse transcriptase (RT)-PCR revealed elevated expression of CXCL10 transcripts during T1R, but not in patients who did not have T1R. No significant correlation between CXCL10 and gamma interferon (IFN-γ) mRNA levels was observed. Immunohistochemical staining of the skin biopsy specimens suggested an overall increase in CXCL10 but did not identify a particular strongly staining population of leukocytes. Increased CXCL10 in lesions and serum is characteristic of T1R. CXCL10 measurement offers new possibilities for laboratory diagnosis and monitoring of T1R. Studies of the regulation of CXCL10 may provide insight into the mechanisms of T1R and identify potential new drug targets for treatment.

Disseminated sclerosing peritoneal mesothelioma in a dog.

A 7-year-old female German Shepherd Dog was presented with multiple petechiae and ecchymoses along the ventral abdomen, flank, and on the vaginal mucosa. The clinical diagnosis was severe hemoperitoneum and presumed disseminated intravascular coagulopathy. Postmortem examination revealed a 22 cm × 15 cm × 6 cm, firm, and convoluted peritoneal mass along with hemoperitoneum, and multifocal, ill-defined, 0.5–1.5 cm in diameter, white to tan nodules in the pulmonary parenchyma. Histologically, the peritoneal mass was composed of large anaplastic cells consistent with malignant mesothelioma interspersed in abundant fibrous connective tissue. Metastasis of the neoplastic cells occurred to the brain, adrenal glands, lymph nodes, and lungs. On immunohistochemical evaluation, neoplastic cells coexpressed cytokeratin and vimentin, and were negative for cluster of differentiation (CD)18. Electron microscopy revealed numerous surface microvilli around the entire circumference of the neoplastic cells, as well as tight junctions, and desmosome-like structures. Based on test findings, a disseminated sclerosing peritoneal mesothelioma was diagnosed.

Nannizziopsis guarroi infection in 2 Inland Bearded Dragons (Pogona vitticeps): clinical, cytologic, histologic, and ultrastructural aspects

Chrysosporium-related infections have been increasingly reported in reptiles over the last 2 decades. In this report, we describe clinical, cytologic, histopathologic, and ultrastructural aspects of Chrysosporium-related infection in 2 Inland Bearded Dragons (Pogona vitticeps). Case 1 was presented for an enlarging raised lesion over the left eye and multiple additional masses over the dorsum. Case 2 was submitted to necropsy by the referring veterinarian for suspected yellow fungus disease. Impression smears of the nodules in case 1 revealed granulomatous to pyogranulomatous inflammation and many septate, variably long, 4-10 μm wide, often undulated hyphae, and very rare conidia. Postmortem impression smears of the superficial lesions of case 2 contained large numbers of solitary conidia and arthroconidia and low numbers of hyphae with similar morphology to case 1. Histopathology of the 2 cases revealed severe, multifocal, chronic, ulcerative, nodular pyogranulomatous dermatitis, with myriad intralesional septate hyphae, and arthroconidia. Fungal culture and molecular sequencing in both cases indicated infection with Nannizziopsis guarroi.

Renal leiomyosarcoma in a cat

Renal leiomyosarcoma was diagnosed in a 10-year-old Domestic Shorthair cat with a 3-year history of clinically managed, chronic renal disease. Sudden death was preceded by a brief episode of mental dullness and confusion. At postmortem examination, the gross appearance of the left kidney was suggestive of hydronephrosis, and a nephrolith was present in the contralateral kidney. However, histology revealed an infiltrative, poorly differentiated, spindle cell sarcoma bordering the grossly cavitated area. Neoplastic cells were immunoreactive for vimentin and smooth muscle actin, which led to a diagnosis of renal leiomyosarcoma; neoplastic cells were not immunoreactive for desmin. Leiomyosarcoma arising in the kidney is a rare occurrence in humans and an even rarer occurrence in veterinary medicine with no prior cases being reported in cats in the English literature. The macroscopic appearance of the tumor at postmortem examination was misleadingly suggestive of hydronephrosis as a result of the large cavitation and may be similar to particularly unusual cases of renal leiomyosarcomas in humans that have a cystic or cavitated appearance.

Disseminated histoplasmosis (Histoplasma capsulatum) in a pet rabbit: case report and review of the literature

A 2.5-year-old intact male miniature lop rabbit (Oryctolagus cuniculus) was presented with multiple nodules surrounding the eyes, nose, mouth, and prepuce. Cytological evaluation of the periocular nodules revealed the presence of intracellular (within macrophages) and extracellular yeast organisms. The yeast organisms were approximately 3–5 µm in diameter, round to oval, with a thin clear capsule, and contained an eccentrically placed basophilic crescent-shaped nucleus. The clinical pathological interpretation was granulomatous inflammation with intralesional yeast of a morphology consistent with Histoplasma spp. The rabbit was treated with microsized griseofulvin (25 mg/kg, orally, once a day) for 12 days pending final cytological diagnosis of histoplasmosis. No significant improvement was noted during the treatment period, and humane euthanasia was performed. Postmortem examination revealed the presence of intracellular and extracellular yeast organisms in the small intestine, skin (antebrachium, perioral, palpebral, perianal, and pinnal), penis, penile urethra, rectum, axillary lymph node, and conjunctiva. Postmortem fungal culture yielded Histoplasma capsulatum. Based on clinical and postmortem findings, a definitive diagnosis of disseminated histoplasmosis was made. Disseminated histoplasmosis appears to be unreported in rabbits. Although the treatment used did not provide noticeable improvement, available information on histoplasmosis treatment in other species has been reviewed to provide useful information for future management of this condition in rabbits.

What is your diagnosis? Abdominal fluid from a dog

A 5-year-old female spayed Dachshund was evaluated at the Louisiana State University (LSU) Veterinary Teaching Hospital and Clinics for chronic diarrhea, vomiting, weight loss, and decreased appetite for 8 weeks. On physical examination, the dog was bright, alert, and responsive and in poor body condition. Cutaneous lesions were not found, and abdominal palpation was within normal limits. A CBC and serum biochemical profile were performed (Table 1). Abdominal ultrasonographic examination revealed moderate anechoic abdominal effusion, corrugation of the small intestine, including the duodenum, and marked thickening of the muscularis layer with preserved layering of the duodenal wall. The liver was hyperechoic with rounded margins, and the spleen was diffusely heterogeneous. Fineneedle aspirates and a tru-cut biopsy of the liver were collected. Endoscopic examination revealed an irregular and thickened, ulcerated, pale duodenal mucosa, and multiple pinch biopsies of duodenum were obtained. Abdominal fluid was blood-tinged, but cleared after centrifugation, and had a total nucleated cell count of 4800/lL and refractometric total protein concentration of 4.1 g/dL. Smears of concentrated abdominal fluid were examined (Figure 1). Figure 1. Concentrated abdominal fluid from a dog. Wright–Giemsa, bar = 10 lm. Table 1. Selected CBC and serum biochemical results from a Dachshund with abdominal effusion.

Mycobacterium Fortuitum Lipoid Pneumonia in a Dog

A 1-year old female spayed German Shepherd dog was evaluated for acute onset of dyspnea. Pyogranulomatous inflammation and green globoid structures were present on aspirates of the affected lung. Impression smears and histopathology confirmed pyogranulomatous pneumonia, with large amounts of lipid corresponding to the green structures noted cytologically, and identified poorly staining bacterial rods within lipid vacuoles. Special stains confirmed the presence of acid-fast bacterial rods, and polymerase chain reaction and DNA sequencing identified the organism as Mycobacterium fortuitum. M. fortuitum pneumonia is well described in humans and has previously been reported in 4 dogs and 1 cat. Lipid was a prominent cytologic and histologic feature, as is often described in humans and in the single feline case report. Additionally, this case highlights the variable cytologic appearance of lipid, as well as Mycobacterium spp, which are classically nonstaining with Wright-Giemsa.