Juan Carlos Cataño

Invariant NKT cells from HIV-1 or Mycobacterium tuberculosis-infected patients express an activated phenotype.

The frequency, subsets and activation status of peripheral blood invariant NKT (iNKT) cells were evaluated in pulmonary tuberculosis (TB) patients and in chronically HIV-1-infected subjects. The absolute numbers of iNKT cells were significantly decreased in TB patients and in HIV-1+ individuals who were antiretroviral therapy naive or had detectable viremia despite receiving HAART. iNKT cell subset analysis demonstrated a decreased percentage of CD4(+) iNKT cells in HIV-1+ subjects, and a decreased percentage of double negative iNKT cells in TB patients. Peripheral blood iNKT cells from HIV-1+ and TB patients had significantly increased expression of CD69, CD38, HLA-DR, CD16, CD56, and CD62L. The expression of CD25 was significantly increased only on iNKT cells from TB patients. These findings indicate that peripheral blood iNKT cells in these two chronic infections show an up-regulated expression of activation markers, suggesting their role in the immune response to infection.

Potential therapeutic failure of generic vancomycin in a liver transplant patient with MRSA peritonitis and bacteremia

We report a case of generic vancomycin treatment failure in a liver transplant patient with MRSA peritonitis and bacteremia, followed by a rapid sterilization of blood and peritoneal fluid after switching to the branded product. It raises concern about therapeutic equivalence of generic vancomycin.

Higher SLPI expression, lower immune activation, and increased frequency of immune cells in a cohort of Colombian HIV-1 controllers.

Background:There are 2 new phenotypes of HIV-1–positive individuals who exhibit a spontaneous and sustained control of viral replication at least for 1 year without antiretroviral therapy (elite controllers <50 copies/mL and viremic controllers <2000 copies/mL). Mechanisms related to this spontaneous control of viral replication are poorly understood. Methods:The study included HIV-1 controllers (patients with at least 1 year of HIV-1 diagnosis, highly active antiretroviral therapy naive, and with viral loads less than 2000 copies/mL) and HIV-1 progressors without antiretroviral therapy (viral load >2500 copies/mL, and CD4+ T-cell count >250 cells/&mgr;L at the time of sampling). The expression of soluble factors, leukocyte protease inhibitor (SLPI) and human &agr;-defensins-1 (HAD-1), was measured by real-time polymerase chain reaction from neutrophil cultures with or without HIV stimulation; the frequency and phenotype of innate and adaptive immune cells were determined by flow cytometry, and frequency of human leukocyte antigen alleles was determined by polymerase chain reaction sequence–specific oligonucleotide typing. Results:As expected, HIV-1 controllers had higher CD4+ T-cell counts and lower viral load when compared with HIV-1 progressor individuals; in addition, they exhibited lower expression of activation markers, higher frequency of myeloid dendritic cell, lower percentage of regulatory T cells and natural killer cells, and higher expression of SLPI. Conclusions:All together, these findings suggest that the control of the immune activation status and the production of antiviral proteins by innate immune cells could be associated to the mechanisms involved in the control of HIV-1 replication and better preservation of the CD4 T-cell count.

Fiebre manchada de las montañas rocosas: ni tan manchada ni tan montañosa como pensábamos

Rocky Mountain Spotted Fever (RMSF) is an infection caused by Rickettsia rickettsii, a pleomorphic cocobacillae which belongs to the Rickettsiaceae family. Although it has been more than a century since its first description, this disease is still one of the most important zoonosis in the world. Usually cases occur in focal and sporadic form, but an unusual increase in the frequency of cases during the last few years has drawn the attention of surveillance systems in United States and some South American countries. Little was known about the disease in Colombia when it was first described in 1937, but in recent years new cases have been reported showing high mortality rates. Since clinical and laboratory findings have not been specific, the RMSF must be included in the differential diagnosis of febrile syndromes of unknown origin. A literature review follows herein, pointing out the most important features of the cases diagnosed in Colombia and highlighting their pathogenesis, clinical manifestations, diagnosis, and treatment, and attempting to improve local knowledge of this infection. The disease is probably under-diagnosed and could be treated with a few doses of PO antibiotics.

Tuberculosis abscess of the chest wall.

A 42-year-old male presented in June of 2011 with nocturnal fevers, night sweats, an 8-kg weight loss, and a cutaneous right chest wall mass. In March of 2013, a computed tomographic scan of the thorax showed a 54 × 18 × 26-mm right lower lobe mass with peripheral calcifications, and in May of 2013, he was admitted for a segmental lobectomy, in which histologic examination of the pulmonary tissue revealed granulomas with multinucleated giant cells. The tissue was negative for acid-fast bacillae on Ziehl–Neelsen stain, and culture grew Mycobacterium tuberculosis. Therefore, he was started on four first-line antituberculosis medications and showed rapid symptomatic improvement.

Perforated Tuberculosis Lymphadenitis

A 26-year-old man (human immunodeficiency virus-positive and not taking highly active antiretroviral treatment [HAART]) presented to the emergency room with 2 months of malaise, 20 kg weight loss, high spiking fevers, generalized lymph nodes, night sweats, dry cough, and chest pain when swallowing. On physical examination, he had multiple cervical lymphadenopathies. Suspecting a systemic opportunistic infection, a contrasted chest computed tomography (CT) was done, showing an esophageal to mediastinum fistulae. Two days after admission, a fluoroscopic contrasted endoscopy was done that showed two esophageal fistulae from scrofula to esophagus and then, to mediastinum. A bronchoalveolar lavage and a cervical lymphadenopathy biopsy were done, both showing multiple acid-fast bacillae, where cultures grew Mycobacterium tuberculosis.

Tuberculous Lymphadenitis and Parotitis

Tuberculous lymphadenitis is the most common extrapulmonary manifestation of disseminated tuberculosis (TB). It is considered to be the local manifestation of the systemic disease that has disseminated to local lymph nodes, but a high index of suspicion is needed for the diagnosis, because there are several infectious and noninfectious diseases that can mimic the same clinical picture. In recent years, different diagnostic methods have been introduced, including fine-needle aspiration cytology, which has emerged as a simple outpatient diagnostic procedure that replaced the complete excisional node biopsy, and a number of molecular methods which have greatly improved diagnostic accuracy. This chapter covers the most actual knowledge in terms of epidemiology, clinical manifestations, pathogenesis, and treatment and emphasizes current trends in diagnosis of tuberculous lymphadenitis. TB parotid gland involvement is extremely rare, even in countries in which TB is endemic. Because of the clinical similarity, parotid malignancy and other forms of parotid inflammatory disease always take priority over the rarely encountered TB parotitis when it comes to differential diagnosis. As a result, clinicians often fail to make a timely diagnosis of TB parotitis when facing a patient with a slowly growing parotid lump. This chapter highlights the most important features of this uncommon disease.

Isoniazid toxicity and TB development during biological therapy of patients with psoriasis in Colombia

Abstract Background The use of biological therapy has been linked with an increased risk of tuberculosis (TB) reactivation. Objective The aim of this study was to present the follow-up results for Isoniazid (INH) chemoprophylaxis in patients with psoriasis receiving different biological therapies. Methods In this prospective observational study, patients with latent tuberculosis infection (LTBI) were given INH chemoprophylaxis between two and nine months prior to the beginning of biological therapy. All patients were followed up monthly for any signs or symptoms of active TB or INH toxicity. Results A total of 101 patients, 44.5% females, with a mean age of 46.9 ± 11.5 years (20–73) were enrolled. LTBI was identified in 100 patients (99%), of whom 81.2% completed nine months of chemoprophylaxis. Three patients (2.9%) developed active TB and 17 patients (16.8%) developed intolerance or toxicity related to INH. Conclusions Chemoprophylaxis with INH seems to be effective and safe for the prevention of most TB reactivations in individuals with LTBI receiving biological therapy, but toxicity must be monitored during follow-up.

Tuberculous sternal osteomyelitis

A 32-year-old female patient with systemic lupus erythematosus presented with 1 month of nocturnal subjective fevers, night sweats, poor appetite, malaise, 8-kg weight loss, and a 6-cm painful sternal mass. She had normal vital signs with a physical examination notable only for the presence of a fluctuating sternal mass. A computed tomographic scan of the thorax showed a 67 × 32 × 27-mm sternal mass associated with severe sternal osteomyelitis (Fig. 1); then a surgical drainage was performed, and abundant caseous material was removed, leaving a penrose drain (Fig. 2). Histologic examination of the bone tissue revealed extensive necrosis and granulomas with multinucleated giant cells. The bone, secretion, and soft tissue were negative for acid-fast bacillae on Ziehl-Neelsen stain; but culture grew Mycobacterioum tuberculosis, and she was started on 4 first-line antituberculosis medications, showing rapid symptomatic improvement, and was discharged 4 weeks after admission (Fig. 3).

Consenso de uso de antimicrobianos en pacientes críticamente enfermos con falla renal o en riesgo de padecerla

A growing number of critically ill patients are being taken care with sepsis secondary to bacterial or mycotic infections. In this group of patients, sepsis per se is a risk factor for the development of renal failure, which has been related to an increased risk of hospital mortality. An expert panel in infectious diseases, critical care and renal diseases prepared an evidence based consensus over the use of antimicrobials (antibacterial and antifungal agents) in critically ill patients with renal failure or at risk of suffering it. A sytematic review of the scientific literature was performed and recommendations were established by means of a consensus using the Delphi method. Recommendations proposed by this consensus are intended to be use by healthcare workers who are in charge of this kind of patients with the aim to identify the group of patients with higher risk of developing renal failure and to establish the therapeutic measures theat have the best outcome and lower frequency of severe side effects in renal function. An implementation strategy was added with the recommendations.