Comparative efficacy and safety of Pneumocystis jirovecii pneumonia prophylaxis regimens for people living with HIV: a systematic review and network meta-analysis of randomized controlled trials.

BACKGROUND: Pneumocystis jirovecii pneumonia (PCP) is a common opportunistic infection among people living with HIV (PWH), particularly among new and untreated cases. Several regimens are available for the prophylaxis of PCP, including trimethoprim-sulfamethoxazole (TMP-SMX), dapsone-based regimens (DBRs), aerosolized pentamidine (AP), and atovaquone. OBJECTIVES: To compare the efficacy and safety of PCP prophylaxis regimens in PWH by network meta-analysis. METHODS: DATA SOURCES: Embase, MEDLINE, and CENTRAL from inception to June 21, 2023. STUDY ELIGIBILITY CRITERIA: Comparative randomized controlled trials (RCTs). PARTICIPANTS: PWH. INTERVENTIONS: Regimens for PCP prophylaxis either compared head-to-head or versus no treatment/placebo. ASSESSMENT OF RISK OF BIAS: Cochrane risk-of-bias tool for RCTs 2. METHODS OF DATA SYNTHESIS: Title or abstract and full-text screening and data extraction were performed in duplicate by two independent reviewers. Data on PCP incidence, all-cause mortality, and discontinuation due to toxicity were pooled and ranked by network meta-analysis. Subgroup analyses of primary versus secondary prophylaxis, by year, and by dosage were performed. RESULTS: A total of 26 RCTs, comprising 55 treatment arms involving 7516 PWH were included. For the prevention of PCP, TMP-SMX was ranked the most favourable agent and was superior to DBRs (risk ratio [RR] = 0.54; 95% CI, 0.36-0.83) and AP (RR = 0.53; 95% CI, 0.36-0.77). TMP-SMX was also the only agent with a mortality benefit compared with no treatment/placebo (RR = 0.79; 95% CI, 0.64-0.98). However, TMP-SMX was also ranked as the most toxic agent with a greater risk of discontinuation than DBRs (RR = 1.25; 95% CI, 1.01-1.54) and AP (7.20; 95% CI, 5.37-9.66). No significant differences in PCP prevention or mortality were detected among the other regimens. The findings remained consistent within subgroups. CONCLUSIONS: TMP-SMX is the most effective agent for PCP prophylaxis in PWH and the only agent to confer a mortality benefit; consequently, it should continue to be recommended as the first-line agent. Further studies are necessary to determine the optimal dosing of TMP-SMX to maximize efficacy and minimize toxicity.

Deep mutational scanning of Pneumocystis jirovecii dihydrofolate reductase reveals allosteric mechanism of resistance to an antifolate.

Pneumocystis jirovecii is a fungal pathogen that causes pneumocystis pneumonia, a disease that mainly affects immunocompromised individuals. This fungus has historically been hard to study because of our inability to grow it in vitro. One of the main drug targets in P. jirovecii is its dihydrofolate reductase (PjDHFR). Here, by using functional complementation of the baker's yeast ortholog, we show that PjDHFR can be inhibited by the antifolate methotrexate in a dose-dependent manner. Using deep mutational scanning of PjDHFR, we identify mutations conferring resistance to methotrexate. Thirty-one sites spanning the protein have at least one mutation that leads to resistance, for a total of 355 high-confidence resistance mutations. Most resistance-inducing mutations are found inside the active site, and many are structurally equivalent to mutations known to lead to resistance to different antifolates in other organisms. Some sites show specific resistance mutations, where only a single substitution confers resistance, whereas others are more permissive, as several substitutions at these sites confer resistance. Surprisingly, one of the permissive sites (F199) is without direct contact to either ligand or cofactor, suggesting that it acts through an allosteric mechanism. Modeling changes in binding energy between F199 mutants and drug shows that most mutations destabilize interactions between the protein and the drug. This evidence points towards a more important role of this position in resistance than previously estimated and highlights potential unknown allosteric mechanisms of resistance to antifolate in DHFRs. Our results offer unprecedented resources for the interpretation of mutation effects in the main drug target of an uncultivable fungal pathogen.

Pneumocystis jirovecii pneumonia prophylaxis in immunocompromised patients with systemic autoimmune diseases / Profilaxis de la neumonía por Pneumocystis jirovecii en pacientes inmunodeprimidos con enfermedades autoinmunes sistémicas

Pneumocystis jirovecii (P. jirovecii) causes a potentially fatal pneumonia in immunocompromised individuals (Pneumocystis pneumonia or PcP), particularly in HIV-infected patients and those treated with immunosuppressive drugs, such as transplant patients and those with systemic autoimmune diseases. P. jirovecii colonization can be found in almost a third of patients with systemic autoimmune diseases. Although the incidence of PcP in such patients is usually low, mortality is quite high, ranging between 30% and 50% in the majority of autoimmune diseases. PcP development is almost always observed in patients not receiving prophylaxis for the infection. Despite the above, there are no clinical guidelines established for PcP prophylaxis in patients with autoimmune diseases treated with glucocorticoids, cytotoxic drugs, or more recently, biological agents. The objective of this review is to analyze the available data on the incidence of PcP and the effect of PcP prophylaxis in patients with autoimmune diseases that may be useful in clinical practice

El hongo Pneumocystis jirovecii (P. jirovecii) es la causa de una neumonía (Pneumocystis pneumonia o PcP) potencialmente mortal en individuos inmunodeprimidos, sobre todo en pacientes infectados por el VIH, y en aquellos tratados con fármacos inmunodepresores, como los sometidos a trasplantes y los afectos de enfermedades autoinmunes sistémicas. En estos últimos, alrededor de un tercio de los casos puede estar colonizado por P. jirovecii y, aunque la incidencia de la PcP suele ser baja, la mortalidad de la misma es considerablemente alta, y oscila entre el 30 y el 50% en la mayoría de las enfermedades autoinmunes. El desarrollo de la PcP se observa casi siempre en pacientes que no reciben profilaxis para la infección. Aun así, no existen guías clínicas establecidas para la profilaxis de la PcP en pacientes afectos de enfermedades autoinmunes que son tratados con glucocorticoides, fármacos citotóxicos o más recientemente, con agentes biológicos. El objetivo de esta revisión es analizar los datos disponibles sobre la incidencia de la PcP y el efecto de la profilaxis para infección por P. jirovecii en los pacientes afectos de enfermedades autoinmunes que puedan ser útiles en la práctica clínica

Criptococosis cutánea / Cutaneous cryptococcosis

No disponible

A Case of Pneumonia Caused by Pneumocystis jirovecii Resistant to Trimethoprim-Sulfamethoxazole

A 50-year-old male visited the outpatient clinic and complained of fever, poor oral intake, and weight loss. A chest X-ray demonstrated streaky and fibrotic lesions in both lungs, and chest CT revealed multifocal peribronchial patchy ground-glass opacities with septated cystic lesions in both lungs. Cell counts in the bronchoalveolar lavage fluid revealed lymphocyte-dominant leukocytosis, and further analysis of lymphocyte subsets showed a predominance of cytotoxic T cells and few T helper cells. Video-assisted wedge resection of the left upper lobe was performed, and the histologic examination was indicative of a Pneumocystis jirovecii infection. Trimethoprim-sulfamethoxazole (TMP-SMX) was orally administered for 3 weeks; however, the patient complained of cough, and the pneumonia was aggravated in the follow-up chest X-ray and chest CT. Molecular studies demonstrated mutations at codons 55 and 57 of the dihydropteroate synthase (DHPS) gene, which is associated with the resistance to TMP-SMX. Clindamycin-primaquine was subsequently administered for 3 weeks replacing the TMP-SMX. A follow-up chest X-ray showed that the pneumonia was resolving, and the cough was also alleviated. A positive result of HIV immunoassay and elevated titer of HCV RNA indicated HIV infection as an underlying condition. This case highlights the importance of careful monitoring of patients with P. jirovecii pneumonia (PCP) during the course of treatment, and the molecular study of DHPS mutations. Additionally, altering the anti-PCP drug utilized as treatment must be considered when infection with drug-resistant P. jirovecii is suspected. To the best of our knowledge, this is the first case of TMP-SMX-resistant PCP described in Korea.

Hipersensibilidade a drogas em paciente com SIDA: relato de caso / Drug hipersensibility and HIV infected patients: case report

A alergia a drogas e frequente em pacientes portadores de HIV, com incidencia maior que na populacao geral. Os autores descrevem uma crianca com SIDA e reacoes adversas a drogas utilizadas na profilaxia do Pneumocystis carinii (Sulfametoxazol-trimetoprim/Pentamidina) e outros antibioticos, entre eles a cefalexina e o cloranfenicol. Sao discutidos os provaveis mecanismos fisiopatologicos das reacoes, drogas alternativas para profilaxia do Pneumocystis carinii e dessensibilizacao para o sulfametoxazol-trimetoprim

Nuevos medicamentos antiprotozoarios y antiartrópodos / New antiprozoan and anti arthropod drugs

Few developments have taqken place in this area, except for the use of trumetroprim and sulfamethoxazole for isospporosis and spiramycin for cryptosporidiosis in immune suppressed patients. For parasitic arthropods, crotamiton and piretoids have been helpful in treating scabies and pediculosis, respectively