Nocardiosis in a patient with pemphigus foliaceus treated with rituximab

Trimethoprim-sulfamethoxazole significantly reduces the risk of nocardiosis in solid organ transplant recipients: systematic review and individual patient data meta-analysis

BACKGROUND

Whether trimethoprim-sulfamethoxazole (TMP-SMX) prophylaxis prevents nocardiosis in solid organ transplant (SOT) recipients is controversial.

OBJECTIVES

To assess the effect of TMP-SMX in the prevention of nocardiosis after SOT, its dose-response relationship, its effect on preventing disseminated nocardiosis, and the risk of TMP-SMX resistance in case of breakthrough infection.

METHODS

A systematic review and individual patient data meta-analysis.

DATA SOURCES

MEDLINE, Embase, Cochrane Central Register of Controlled Trials, Cochrane Database of Systematic Reviews, Web of Science Core Collection, and Scopus up to 19 September 2023.

STUDY ELIGIBILITY CRITERIA

(a) Risk of nocardiosis between SOT recipients with and without TMP-SMX prophylaxis, or (b) sufficient details to determine the rate of TMP-SMX resistance in breakthrough nocardiosis.

PARTICIPANTS

SOT recipients.

INTERVENTION

TMP-SMX prophylaxis versus no prophylaxis.

ASSESSMENT OF RISK OF BIAS

Risk Of Bias In Non-randomized Studies-of Exposure (ROBINS-E) for comparative studies; dedicated tool for non-comparative studies.

METHODS OF DATA SYNTHESIS

For our primary outcome (i.e. to determine the effect of TMP-SMX on the risk of nocardiosis), a one-step mixed-effects regression model was used to estimate the association between the outcome and the exposure. Univariate and multivariable unconditional regression models were used to adjust for the potential confounding effects. Certainty of evidence was assessed using Grading of Recommendations Assessment, Development and Evaluation (GRADE) approach.

RESULTS

Individual data from three case-control studies were obtained (260 SOT recipients with nocardiosis and 519 uninfected controls). TMP-SMX prophylaxis was independently associated with a significantly decreased risk of nocardiosis (adjusted OR = 0.3, 95% CI 0.18-0.52, moderate certainty of evidence). Variables independently associated with an increased risk of nocardiosis were older age, current use of corticosteroids, high calcineurin inhibitor concentration, recent acute rejection, lower lymphocyte count, and heart transplant. Breakthrough infections (66/260, 25%) were generally susceptible to TMP-SMX (pooled proportion 98%, 95% CI 92-100).

CONCLUSIONS

In SOT recipients, TMP-SMX prophylaxis likely reduces the risk of nocardiosis. Resistance appears uncommon in case of breakthrough infection.

Current biologics in treatment of pemphigus foliaceus: a systematic review

Background

Pemphigus foliaceus (PF) differs from pemphigus vulgaris (PV) in that it affects only the skin and mucous membranes are not involved. Pemphigus is commonly treated with systemic corticosteroids and immunosuppressive agents (ISAs). More recently, biologics have been used. The current literature on biologic therapy often combines treatment of PF with PV, hence it is often difficult for clinicians to isolate the treatment of PF from PV. The purpose of this review was to provide information regarding the use of current biological therapy, specifically in PF.

Materials and methods

A search of PubMed, Embase, and other databases was conducted using keywords pemphigus foliaceus (PF), rituximab (RTX), intravenous immunoglobulin (IVIg), and biologics. Forty-one studies were included in this review, which produced 105 patients with PF, treated with RTX, IVIg, or a combination of both. Eighty-five patients were treated with RTX, eight patients with IVIg, and 12 received both RTX and IVIg.

Results

Most patients in this review had PF that was nonresponsive to conventional immunosuppressive therapies (CIST), and had significant side effects from their use. RTX treatment resulted in complete remission (CR) in 63.2%, a relapse rate of 39.5%, an infection rate of 19.7%, and a mortality rate of 3.9%. Relapse was greater in the lymphoma (LP) protocol than the rheumatoid arthritis (RA) protocol (p<0.0001). IVIg led to CR in 62.5% of patients, with no relapses or infections. Patients receiving both biologics experienced better outcomes when RTX was first administered, then followed by IVIg. Follow-up durations for patients receiving RTX, IVIg, and both were 22.1, 24.8, and 35.7 months, respectively.

Discussion

In pemphigus foliaceus patients nonresponsive to conventional immunosuppressive therapy or in those with significant side effects from CIST, RTX and IVIg appear to be useful agents. Profile of clinical response, as well as relapse, infection, and mortality rates in PF patients treated with RTX were similar to those observed in PV patients. The data suggests that protocols specific for PF may produce better outcomes, less adverse effects, and improved quality of life.