Cavitary Legionella Pneumonia in AIDS: When Intracellular Immunity Failure Leads to Rapid Intrapulmonary Cavitation.

Introduction. Legionella is a frequent cause of bacterial pneumonia in patients with AIDS. While multiple organisms have been associated with cavitary pneumonia in this population, Legionella has not. Clinical Case. A middle-aged woman with HIV-AIDS and severely depressed CD-4 count presented with one month of progressively worsening productive cough and dyspnea. Serial imaging showed focal consolidations which multiplied and cavitated over the subsequent days. Legionella urine antigen was positive, and appropriate treatment was continued for 3 weeks total. The patient recovered quickly, and follow-up imaging 8 weeks later showed near-resolution of all lesions. Discussion. Cavitary pneumonia secondary to Legionella has been seldom described, traditionally in the context of immunosuppressive therapy. Patients with AIDS and severely depressed CD4 counts have significantly compromised cell-mediated immunity. This case highlights the importance of consideration for legionellosis in rapidly progressing cavitary pneumonia, especially in patients with severely compromised cell-mediated immunity, including those with HIV-AIDS.

Tocilizumab for Severe and Critical COVID-19 Pneumonia in Queens, NYC.

New York City was hard hit by COVID-19. Elmhurst Hospital is a public hospital in Queens where more than 1500 patients were hospitalized with COVID. During the pandemic, various treatments were used with hopes of reducing the need for mechanical ventilation and death. METHODS: We retrospectively reviewed charts of patients admitted from March 25 to April 3 with severe or critical COVID-19 pneumonia who received tocilizumab compared with a similar cohort who did not. Analyses were performed to determine differences in outcomes. RESULTS: There was no observed difference in need for mechanical ventilation, length of stay, or mortality rate. In the tocilizumab-treated group, mechanical ventilation rate was 55%, and 49% of patients died. In the control group, 54% required mechanical ventilation and 46% died. Tocilizumab was overall well tolerated, although alanine aminotransferase elevation was more common in the tocilizumab-treated group. CONCLUSIONS: Tocilizumab failed to show short-term benefits in clinical outcomes in patients with hypoxic COVID pneumonia at our institution.

Relapsing Malaria: A Case Report of Primaquine Resistance.

Primaquine (an 8-aminoquinoline malarial therapy) is the only FDA-approved therapy to treat the hypnozoite stage of P. vivax. We think of relapse occurring because of parasitic resistance or poor compliance secondary to drug toxicities. However, in patients with repeated treatment failure, we must consider CYP-450 mutations affecting drug metabolism as an important cause of relapse. A 47-year-old man who travelled to a jungle in Venezuela was diagnosed with P. falciparum and P. vivax in July 2015. He was treated with seven rounds of primaquine-based therapy in the following year, all resulted in relapse without further exposure to endemic areas. On his eighth presentation, he was found to have CYP-4502D6 mutation that affected the metabolism and activation of primaquine. Thereafter, he was treated without relapse. Primaquine efficacy depends on many factors. Understanding the mechanism responsible for malaria relapse is paramount for successful treatment and reduction in morbidity and mortality. This case illustrates the importance of considering cytochrome mutations that affect drug efficacy in cases of relapsing malaria.

S-adenosylmethionine concentrations in diagnosis of Pneumocystis carinii pneumonia.

Pneumocystis carinii is unable to synthesise S-adenosylmethionine and thus scavenges this intermediate. We aimed to test whether measurement of concentrations of this metabolic intermediate in plasma could provide a new method for rapid diagnosis of Pneumocystis carinii pneumonia (PCP). We measured S-adenosylmethionine plasma concentrations in 12 healthy controls, 16 patients with confirmed or suspected PCP, and 36 patients with other infections. Median concentration in healthy controls was 106 nmol/L (range 86-128), but the protein was undetectable in eight patients with histologically proven and seven with suspected PCP, and was 8 nmol/L in another confirmed case (p<0.0001). In 36 patients with other infections, S-adenosylmethionine concentrations were much the same as in controls: 18 had bacterial pneumonia, two tuberculosis, five cryptococcal meningitis, three had other infections, and eight had asymptomatic HIV-1 infection. After treatment for PCP, S-adenosylmethionine concentrations rose rapidly in all but one patient who died of the disease. Measurement of plasma S-adenosylmethionine concentrations could prove useful for diagnosis of PCP and assessment of patients' response to treatment.

Hantavirus Pulmonary Syndrome in the United States.

Since the first outbreak of hantavirus pulmonary syndrome (HPS) in 1993, understanding of the vast distribution and potential impact of hantaviruses has grown. At least 277 cases of HPS have been documented in the United States. The full clinical spectrum has yet to be elucidated, and one outbreak suggested the possibility of person-to-person transmission. New research has identified the b-3 integrins as cellular receptors for hantaviruses and has determined the pivotal role of the immune system in pathogenesis. Rapid diagnosis has been facilitated by a new immunoblot assay to detect Sin Nombre virus infection. Treatment remains primarily supportive; however, a placebo- controlled trial of ribavirin is ongoing. Extracorporeal membrane oxygenation may be a potential therapy in severe cases; inhaled nitric oxide needs further study. Vaccines developed against hantaviruses associated with hemorrhagic fever and renal syndrome might be effective against HPS-associated strains.