Risk factors and prophylaxis for nocardiosis in solid organ transplant recipients: A nested case-control study

Evaluation of the Incidence of Nocardia Infection in Solid Organ Transplant Recipients on Trimethoprim-Sulfamethoxazole for Opportunistic Infection Prophylaxis

BACKGROUND

Trimethoprim-sulfamethoxazole (TMP-SMX) is the preferred prophylactic agent for Pneumocystis jiroveci pneumonia (PJP) and toxoplasmosis after solid organ transplant (SOT). Compared with other agents, it has additional activity against Nocardia species.

OBJECTIVE

The purpose of this study was to evaluate the incidence of Nocardia infection in SOT patients receiving TMP-SMX or an alternative agent for opportunistic infection (OI) prophylaxis.

METHODS

This retrospective analysis included transplant recipients at a large urban medical center over a period of 4 years. All patients received either TMP-SMX or an alternative agent for PJP prophylaxis. The primary outcome was the incidence of Nocardia infection within 24 months posttransplant. Secondary outcomes included resistance rates of Nocardia isolates, usage rates of alternative prophylactic agents, reasons for using alternative agents, and rate of conversion from an alternative agent back to TMP-SMX.

RESULTS

A total of 791 adult SOT recipients who received PJP or toxoplasmosis prophylaxis were included. Mean age at transplantation was 60.9 years with the majority of patients being male (67.3%) lung transplant recipients (63.6%). TMP-SMX was the most commonly used initial prophylactic agent (84.6%), followed by atovaquone (15.4%). Of the 791 SOT recipients, 16 (2.0%) were diagnosed with nocardiosis within 24 months posttransplant. Patients receiving alternative agents had a higher incidence of infection compared with those receiving TMP-SMX prophylaxis (P < 0.001).

CONCLUSION AND RELEVANCE

Our findings suggest that OI prophylaxis with TMP-SMX may be protective against nocardiosis in SOT recipients. If possible, patients who are switched to an alternative agent due to TMP-SMX intolerance should be re-challenged when the adverse effect resolves. Most patients in our study were able to tolerate re-initiation, suggesting that the adverse effects associated with TMP-SMX may be temporary and may not warrant discontinuation.

Premature Discontinuation of Trimethoprim/Sulfamethoxazole Prophylaxis in Abdominal Transplant Recipients: A Deeper Dive

Trimethoprim/sulfamethoxazole (TMP/SMX) prophylaxis can prevent Pneumocystis jirovecii pneumonia (PJP) and other opportunistic infections (OI). We sought to assess the frequency, causative factors, and impact of early TMP/SMX discontinuation in abdominal solid organ transplant (SOT). This is a single-center, retrospective cohort study of abdominal SOT recipients at Mayo Clinic Arizona (MCA) between January 2021 and June 2023. Primary study goals were to determine the rate and reasons behind early TMP/SMX discontinuation and whether TMP/SMX prophylaxis was reinitiated. Secondary outcomes included mean duration of therapy, alternative prophylactic agent utilized, and incidence of TMP/SMX-preventable OI. A total of 930 abdominal SOT recipients were included (592 kidney, 253 liver, 85 multiorgan transplants). TMP/SMX was discontinued early in 184 (20%) patients: 77 kidney, 84 liver, 23 multiorgan. Predominant reasons for discontinuation were hyperkalemia (39%) and cytopenias (35%). Median duration of TMP/SMX prophylaxis before discontinuation was 54.5 (18.0, 93.2) days. TMP/SMX was not resumed in 62% of cases (36% kidney, 89% liver, 52% multi-organ). The predominant reason for non-resumption was alternative prophylaxis with no clear intent to rechallenge TMP/SMX (70%). Alternative prophylaxis included pentamidine (43%), none (30%), dapsone (22%), and atovaquone (5%). Of patients reinitiated, 86% (59/69) successfully remained on TMP/SMX through the prophylaxis period. One TMP-SMX-preventable OI (nocardiosis) was observed in the TMP/SMX discontinuation group. TMP/SMX is often discontinued prematurely in SOT recipients without resumption despite resolution of the offending cause. TMP/SMX prophylaxis should be maintained where possible, as alternative therapy may not offer the same broad spectrum of protection against OI.

State-of-the-Art Review: Modern Approach to Nocardiosis-Diagnosis, Management, and Uncertainties

Nocardiosis is an uncommon yet potentially devastating infection. Nocardia tends to affect individuals with chronic lung disease or immunocompromising conditions, 2 groups increasing in number. Incidence of nocardiosis is likely to increase as well, and it is vital to have an approach to this complex disease. Here, we aim to review the presentation, diagnosis, and management of Nocardia in the modern era. We will also highlight areas of uncertainty in our understanding of nocardiosis and propose a general approach to nocardiosis therapy, accounting for response and tolerance of Nocardia treatment.

Chronic inflammatory demyelinating polyneuropathy with pulmonary nocardiosis: A case report

RATIONALE

Chronic inflammatory demyelinating polyneuropathy (CIDP) is an immune-mediated motor sensory peripheral neuropathy that is rare in clinical practice. This treatment method aims to suppress potential immunopathology. Nocardiosis is a rare, destructive, opportunistic disease. We report a case of failed treatment of CIDP combined with pulmonary nocardiosis, and for the first time, we link these 2 diseases together.

PATIENT CONCERNS

A 65-year-old man developed symmetrical limb weakness. Four months later, he was diagnosed with CIDP and started receiving glucocorticoid (GC) treatment. The disease progressed slowly and was treated with mycophenolate mofetil (MMF) in combination. He did not follow the doctor requirements for monthly follow-up visits, and the preventive medication for sulfamethoxazole/trimethoprim was not strictly implemented. Two months after the combination therapy, the patient developed fever, coughing and sputum production, as well as fatigue and poor appetite. Based on imaging and etiological results, he was diagnosed with pulmonary nocardiosis.

DIAGNOSES

Chronic inflammatory demyelinating polyneuropathy, pulmonary nocardiosis.

INTERVENTIONS

After treatment with antibiotics, the patient lung infection temporarily improved. However, the patient CIDP condition progressed, limb weakness worsened, respiratory muscle involvement occurred, and intravenous immunoglobulin (IVIG) was administered. However, there was no significant improvement in the condition, and the patient died.

OUTCOMES

In this report, we present a case of a patient with CIDP and pulmonary nocardiosis. It is worth noting that in order to avoid the progression and recurrence of CIDP, we did not stop using related therapeutic drugs during the treatment process, the patient had repeatedly refused to use IVIG. Despite this, the patient condition worsened when lung inflammation improved, leading to persistent respiratory failure and ultimately death. Treatment contradictions, medication issues, and patient compliance issues reflected in this case are worth considering.

LESSONS

For patients with CIDP receiving immunosuppressive therapy, attention should be paid to the occurrence and severity of Nocardia infection. Therefore, early detection and treatment are necessary. We need to pay attention to the compliance of patients with prophylactic use of antibiotics, strengthen the follow-up, and urge them to return to their appointments on time.

Nocardiosis in Solid Organ Transplant Recipients: 10-Year Single Center Experience and Review of Literature

Solid organ transplant recipients (SOTRs) are at an increased risk of nocardiosis, a rare but life-threatening opportunistic infection. Universal PCP prophylaxis with trimethoprim-sulfamethoxazole (TMP-SMX) is used at our center, which is active in vitro against most species of the Nocardia genus and may have a role in preventing early infections. This is a single-center retrospective cohort study of nocardiosis in adult SOTRs at a large transplant center between January 2012 and June 2022, with comprehensive review of literature. Out of 6179 consecutive cases, 13 (0.2%) were diagnosed with nocardiosis. The patients were predominantly male (76.9%) and kidney transplant recipients (62%). Infection was diagnosed at median of 8.8 months (range, 3.7-98) after transplant. Patients were followed for a median of 457 days (range 8-3367). Overall mortality within one year after diagnosis was 46% (6/13), of which 17% (1/6) of deaths was attributable to Nocardia infection. No recurrence was reported. Nocardia infections were noted in a small proportion of our SOTRs and carried significant morbidity and mortality. TMP-SMX prophylaxis may be protective in some cases given low incidence of cases.

Impact of Sulfonamide Allergy Label on Clinical Outcomes in Patients with Pneumocystis jirovecii Pneumonia

INTRODUCTION

The presence of antibiotic allergy labels can have harmful impacts on clinical outcomes, particularly among immunosuppressed patients, in whom there have been associations with increased complications, readmission rates, and mortality. We explore the effects of a sulfonamide allergy label (SAL) on clinical outcomes in adult patients with Pneumocystis jirovecii pneumonia (PJP).

METHODS

In this retrospective matched cohort study, we utilized TriNetX, a multicenter national database, to match 535 adult patients with PJP and SAL to an equal number of controls. We identified cases indexed between 01/01/2010 and 01/01/2023 utilizing ICD-10 codes for PJP and allergy status to sulfonamides and through detection of P. jirovecii antigen with immunofluorescence or PCR. Propensity score matching was performed in a 1:1 fashion for demographics and comorbidities, and our analysis included clinical outcomes that occurred within 30 days after the occurrence of the index event.

RESULTS

While hospitalization risk tended to be lower among patients with SAL as compared to controls (RR: 0.90; 95% CI 0.81-1.01), there were no major differences in the risk of respiratory failure (RR: 0.94; 95% CI 0.84-1.05), prednisone use (RR: 1; 95% CI 0.91-1.10), intensive level of care requirement (RR: 0.85; 95% CI 0.69-1.06), intubation (RR: 0.85; 95% CI 0.61-1.19), or mortality (RR: 0.98; 95% CI 0.68-1.42). The presence of SAL did however impact antibiotic prescription patterns, with an underutilization of trimethoprim (RR: 0.50; 95% CI 0.43-0.59) and sulfamethoxazole (RR, 0.47; 95% CI 0.40-0.56) and overuse of alternative agents by patients with SAL as compared to controls. Yet, there was no difference in the occurrence of adverse outcomes such as hepatotoxicity (RR: 1.09; 95% CI 0.49-2.45) or acute kidney injury (RR: 0.94; 95% CI 0.78-1.14) between patients with SAL and controls.

CONCLUSIONS

The presence of SAL alters antibiotic prescription patterns among adults with Pneumocystis infection but has no clinically significant impact on outcomes.

Epidemiology, Timing, and Secondary Prophylaxis of Recurrent Nocardiosis

Background

Nocardia tends to cause infection in immunocompromised patients or those with chronic pulmonary disease. Nocardia is known to recur, prompting the practice of secondary prophylaxis in patients perceived at high risk. However, few data exist regarding the epidemiology of recurrent nocardiosis or the effectiveness of secondary prophylaxis.

Methods

We performed a multicenter, retrospective cohort study of adults diagnosed with nocardiosis from November 2011 to April 2022, including patients who completed primary treatment and had at least 30 days of posttreatment follow-up. Propensity score matching was used to analyze the effect of secondary prophylaxis on Nocardia recurrence.

Results

Fifteen of 303 (5.0%) patients developed recurrent nocardiosis after primary treatment. Most recurrences were diagnosed either within 60 days (N = 6/15, 40.0%) or between 2 to 3 years (N = 4/15, 26.7%). Patients with primary disseminated infection tended to recur within 1 year, whereas later recurrences were often nondisseminated pulmonary infection. Seventy-eight (25.7%) patients were prescribed secondary prophylaxis, mostly trimethoprim-sulfamethoxazole (N = 67/78). After propensity-matching, secondary prophylaxis was not associated with reduced risk of recurrence (hazard ratio, 0.96; 95% confidence interval, .24-3.83), including in multiple subgroups. Eight (53.3%) patients with recurrent nocardiosis required hospitalization and no patients died from recurrent infection.

Conclusions

Recurrent nocardiosis tends to occur either within months because of the same Nocardia species or after several years with a new species. Although we did not find evidence for the effectiveness of secondary prophylaxis, the confidence intervals were wide. However, outcomes of recurrent nocardiosis are generally favorable and may not justify long-term antibiotic prophylaxis for this indication alone.

Skin and soft tissue infections in solid organ transplants

PURPOSE OF REVIEW

Skin and soft tissue infections (SSTI) in solid organ transplant (SOT) recipients may be a great challenge for clinicians caring for SOT due to the involvement of both common and opportunistic pathogens associated with a blunted immune response. The purpose of this review is to outline current literature and describe open issues on the management of SSTI in this special population.

RECENT FINDINGS

Clinical presentation in SOT recipients can manifest as isolated skin lesions after primary inoculation or be the sign of a disseminated infection. Tissue samples for microscopy and histopathology are crucial to making an accurate diagnosis given the nonspecific and heterogeneous appearance of skin lesions. Multidisciplinary teams are required for a comprehensive diagnosis and management.

SUMMARY

SSTI are frequent contributors to morbidity and mortality in SOT. Specific research focused on the clinical presentation, risk factors and management in this special population is needed.

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.

Outcomes of transplant recipients with pretransplant Nocardia colonization or infection

BACKGROUND

Specific pretransplant infections have been associated with poor posttransplant outcomes. However, the impact of pretransplant Nocardia isolation has not been studied.

METHODS

We performed a retrospective study from three centers in Arizona, Florida, and Minnesota of patients with Nocardia infection or colonization who subsequently underwent solid organ or hematopoietic stem cell transplantation from November 2011 through April 2022. Outcomes included posttransplant Nocardia infection and mortality.

RESULTS

Nine patients with pretransplant Nocardia were included. Two patients were deemed colonized with Nocardia, and the remaining seven had nocardiosis. These patients underwent bilateral lung (N = 5), heart (N = 1), heart-kidney (N = 1), liver-kidney (N = 1), and allogeneic stem cell transplantation (N = 1) at a median of 283 (interquartile range [IQR] 152-283) days after Nocardia isolation. Two (22.2%) patients had disseminated infection, and two were receiving active Nocardia treatment at the time of transplantation. One Nocardia isolate was resistant to trimethoprim-sulfamethoxazole (TMP-SMX) and all patients received TMP-SMX prophylaxis posttransplant, often for extended durations. No patients developed posttransplant nocardiosis during a median follow-up of 1.96 (IQR 0.90-6.33) years. Two patients died during follow-up, both without evidence of nocardiosis.

CONCLUSIONS

This study did not identify any episodes of posttransplant nocardiosis among nine patients with pretransplant Nocardia isolation. As patients with the most severe infections may have been denied transplantation, further studies with larger sample sizes are needed to better analyze any impact of pretransplant Nocardia on posttransplant outcomes. However, among patients who receive posttransplant TMP-SMX prophylaxis, these data suggest pretransplant Nocardia isolation may not impart a heightened risk of posttransplant nocardiosis.