Disseminated Nocardia paucivorans infection in an immunocompetent host

Nocardia Infection in Patients With Anti-Granulocyte-Macrophage Colony-Stimulating Factor Autoantibodies: A Prospective Multicenter French Study

Background

Nocardiosis, a bacterial opportunistic infection caused by Nocardia spp, has recently been reported in patients with anti-granulocyte-macrophage colony-stimulating factor (GM-CSF) autoantibodies, but insufficient data are available about disease presentation, outcomes, and occurrence of autoimmune pulmonary alveolar proteinosis (aPAP) in this population.

Methods

We performed a prospective, multicenter, nationwide study in France and included patients with a Nocardia infection who had anti-GM-CSF autoantibodies. We describe their clinical, microbiological, and radiological characteristics, and their outcome at 1 year of follow-up.

Results

Twenty patients (18 [90%] male) were included, with a median age of 69 (interquartile range, 44-75) years. The organs most frequently involved were the brain (14/20 [70%]) and the lung (12/20 [60%]). Half of the infections were disseminated (10/20 [50%]). Nocardia identification was predominantly made in abscess fluid (17/20 [85%]), among which 10 (59%) were brain abscesses. The 1-year all-cause mortality was 5% (1/20), and only 1 case of aPAP (1/20 [5%]) occurred during the follow-up period.

Conclusions

Nocardiosis with anti-GM-CSF autoantibodies is associated with a low mortality rate despite a high incidence of brain involvement. Although the occurrence of aPAP was infrequent during the 1-year follow-up period, long-term clinical data are needed to fully understand the potential relationship between nocardiosis, anti-GM-CSF autoantibodies, and aPAP.

[Acute abdomen-Rare cause in an 80-year-old female patient under immunosuppressive treatment]

An 80-year-old woman presented to the emergency department due to abdominal pain. She had a history of opportunistic pneumonia under the effects of immunosuppression after the diagnosis of autoimmune hepatitis. The imaging showed an omental cake formation and the suspicion of peritoneal carcinomatosis. The patient developed an acute abdomen during the hospital stay, followed by exploratory laparotomy. In the presence of extensive intra-abdominal abscess formation both surgically acquired material and blood culture revealed disseminated nocardiosis. The course was fatal due to fulminant septic shock.

A 53-Year-Old Woman With Seizure and Cavitary Lung Mass

CASE PRESENTATION

A 53-year-old woman with no significant past medical history came to her local ED after a witnessed generalized tonic-clonic seizure. CT scan imaging of the head revealed a left frontal lobe hypodensity concerning for a mass with surrounding edema. In the previous month, she had undergone ambulatory evaluation for a subacute cough that had more recently become productive of bloody sputum. Outpatient chest radiography had demonstrated a new right lung opacity, shown on subsequent CT scan imaging to be a right upper lobe (RUL) consolidation. She was prescribed a course of doxycycline, after which sputum expectoration improved but a nonproductive cough remained. Repeat thoracic imaging was pending at the time the seizure occurred. The patient had no history of chronic lung disease or recurrent infections. There were no constitutional symptoms. She did not take any home medications on a regular basis. She was a lifetime nontobacco user. She denied use of alcohol and illicit drugs. She had previously worked in a medical office but was now spending most of her time helping her husband take care of their house and property in Kingston, New York, a town of about 23,000 people in the Hudson River Valley. She was born in the United States and had not traveled recently. She had no pets. There was no history of recent dental procedures. She was transferred to our institution for neurosurgical evaluation.

Rapid detection of pulmonary nocardiosis by metagenomic next generation sequencing

We retrospectively analyzed 3 cases of pulmonary nocardiosis. Patients were identified by metagenomic next generation sequencing (mNGS) in the First Affiliated Hospital of Soochow University, from January 2019 to April 2022. All patients had underlying diseases, and were in immunocompromised state, with membranous nephropathy, acute lymphoblastic leukemia (ALL), and systemic lupus erythematosus (SLE), respectively. Symptoms common to all cases included fever, cough and expectoration. Chest computed tomography (CT) presented patchy shadows or nodules, with or without cavitation lesions, or pleural effusion. mNGS detected Nocardia spp. via bronchoalveolar lavage fluid (BALF) or blood samples from patients. All the patients were discharged with recovery after using the trimethoprim-sulfamethoxazole (TMP-SMX) and remained without evidence of disease during regular follow-ups. mNGS may be a tool for rapid and accurate detection and identification of pulmonary nocardiosis, but interpreting the mNGS results should be more cautious because the mNGS assay can also detect colonization.

Disseminated Nocardia paucivorans Infection Resembling Metastatic Disease in a Kidney Transplant Recipient

Recipients of solid-organ transplants (SOT) or hematopoietic stem-cell transplants are prone to various complications, including serious infections. Nocardiosis is an opportunistic bacterial infection that primarily affects the lung. It may also cause skin and soft-tissue infection, cerebral abscess, bloodstream infection, or infection involving other organs. We present a case of an immunocompromised kidney transplant recipient who experienced a prolonged history of unexplained indolent constitutional symptoms without a fever. Initial radiographic findings were suggestive of metastatic disease at multiple sites. However, metagenomic next-generation sequencing of microbial cell-free DNA in blood revealed disseminated Nocardia paucivorans infection, and organisms consistent with Nocardia were identified on histopathology of a lung biopsy. It is crucial for healthcare providers to be aware of unusual opportunistic infections to provide appropriate workups and interventions for immunocompromised SOT recipients.

Disseminated Nocardia Paucivorans in an immunocompetent patient: A case report and literature review

Nocardia paucivorans can cause disseminated infection in immunocompetent hosts in rare occasions. Nocardia paucivorans is usually susceptible to many antibiotics including Trimethoprim/Sulfamethoxazole. Duration of treatment is usually 6-12 months.

Disseminated Nocardiosis Masquerading as Soft-Tissue Malignancy: A Case Report

CASE

A 59-year-old man, immunosuppressed after renal transplant, presented with a painful posterior thigh mass concerning for malignancy, as well as pulmonary and posterior chest wall nodules. Cultures and mass spectrometry identified Nocardia paucivorans. The patient underwent operative irrigation and debridement of the posterior thigh and chest wall, with 12 months of antibiotic therapy.

CONCLUSION

A 2-week delay in appropriate treatment was due to low suspicion for infectious etiology. Since cultures generally take weeks for positive diagnosis, advanced molecular or biochemical methods should be used. This case demonstrates importance in maintaining a high index of suspicion for nocardiosis in immunocompromised patients with soft-tissue masses.

Intra-Abdominal Nocardiosis-Case Report and Review of the Literature

Nocardiosis is primarily an opportunistic infection affecting immunosuppressed individuals, in whom it most commonly presents as pulmonary infection and sometimes cerebral abscesses. Isolated abdominal or retroperitoneal nocardiosis is rare. Here, we report the second case, to our knowledge, of isolated abdominal nocardiosis due to Nocardia paucivorans and provide a comprehensive review of intra-abdominal nocardiosis. The acquisition of abdominal nocardiosis is believed to occur via hematogenous spreading after pulmonary or percutaneous inoculation or possibly via direct abdominal inoculation. Cases of Nocardia peritonitis have been reported in patients on peritoneal dialysis. Accurate diagnosis of abdominal nocardiosis requires histological and/or microbiological examination of appropriate, radiologically or surgically obtained biopsy specimens. Malignancy may initially be suspected when the patient presents with an abdominal mass. Successful therapy usually includes either percutaneous or surgical abscess drainage plus prolonged combination antimicrobial therapy.

Manifestations and outcomes of nocardia infections: Comparison of immunocompromised and nonimmunocompromised adult patients

Nocardia is a ubiquitous environmental pathogen that causes infection primarily following inhalation into the lungs. It is generally thought to cause infection primarily in immunocompromised patients, but nonimmunocompromised individuals are also at risk of infection. We sought to compare risk factors, clinical manifestations, diagnostic approach, treatment, and mortality in immunocompromised and nonimmunocompromised adults with nocardiosis.We studied all adults with culture-proven Nocardia infection at a tertiary care hospital from 1994 to 2015 and compared immunocompromised with nonimmunocompromised patients. The immunocompromised group included patients who had a solid organ transplant, hematopoietic cell transplant (HCT), hematological or solid tumor malignancy treated with chemotherapy in the preceding 90 days, inherited immunodeficiency, autoimmune/inflammatory disorders treated with immunosuppressive agents, or high-dose corticosteroid therapy for at least 3 weeks before the diagnosis of nocardiosis.There were 112 patients, mean age 55 ± 17 years; 54 (48%) were women. Sixty-seven (60%) were immunocompromised, and 45 (40%) were nonimmunocompromised. The lung was the site of infection in 54 (81%) immunocompromised and 25 (55%) nonimmunocompromised patients. Pulmonary nocardiosis in immunocompromised patients was associated with high-dose corticosteroids, P = .002 and allogeneic HCT, P = .01, and in nonimmunocompromised patients with cigarette smoking, bronchiectasis, and other chronic lung diseases, P = .002.Cavitation occurred only in the immunocompromised group, P < .001. Disseminated infection was more common in the immunocompromised, P = .01, and was highest in solid organ transplant recipients, P = .007. Eye infection was more common in nonimmunocompromised patients, P = .009. Clinical signs and symptoms did not differ significantly between the 2 groups. The initial treatment for most patients in both groups was trimethoprim-sulfamethoxazole with or without a carbapenem. All-cause 1-year mortality was 19%; 18 (27%) immunocompromised and 3 (7%) nonimmunocompromised patients died, P = .01.Immunocompromised patients with nocardiosis had more severe disease and significantly higher mortality than nonimmunocompromised patients, but clinical presentations did not differ.

Nocardia paucivorans brain abscess. Clinical and microbiological characteristics

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Brain abscess caused by Nocardia paucivorans is an infrequent infection in humans.

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Molecular speciation has revolutionized the study of Nocardia spp. infections.

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N. paucivorans brain abscess has a favourable prognosis with long-term antimicrobial therapy.

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Antimcirobial susceptibility testing is a useful guide to therapy.

Nocardia paucivorans brain abscesses are unusual in humans. Sixteen cases of this infection have been reported in the world medical literature. There is precise clinical information available from nine patients. All of these patients recovered or were cured from their brain disease with long-term antimicrobial treatment. Surgical drainage was performed in four patients.

Brain Abscesses Caused by Nocardia paucivorans in a Multiple Myeloma Patient Treated with Lenalidomide and Dexamethasone: a Case Report and Review of Literature

We report the first case of multiple brain abscesses caused by Nocardia paucivorans in a patient suffering from multiple myeloma on treatment with lenalidomide and dexamethasone. N. paucivorans is a recently described species of the genus Nocardia, which is supposed to have a heightened neurotropism in cases of disseminated infection. Although nocardiosis itself is an uncommon infectious complication in multiple myeloma so far, nocardial brain abscess should be added to the spectrum of adverse effects due to this novel chemotherapy regimen.

Nocardia-induced granulocyte macrophage colony-stimulating factor is neutralized by autoantibodies in disseminated/extrapulmonary nocardiosis

BACKGROUND

Nocardia species cause infections in both immunocompromised and otherwise immunocompetent patients, although the mechanisms defining susceptibility in the latter group are elusive. Anticytokine autoantibodies are an emerging cause of pathogen-specific susceptibility in previously healthy human immunodeficiency virus-uninfected adults, including anti-granulocyte macrophage colony-stimulating factor (GM-CSF) autoantibodies with cryptococcal meningitis.

METHODS

Plasma from patients with disseminated/extrapulmonary nocardiosis and healthy controls was screened for anticytokine autoantibodies using a particle-based approach. Autoantibody function was assessed by intranuclear staining for GM-CSF-induced STAT5 phosphorylation in normal cells incubated with either patient or normal plasma. GM-CSF-mediated cellular activation by Nocardia was assessed by staining for intracellular cytokine production and intranuclear STAT5 phosphorylation.

RESULTS

We identified neutralizing anti-GM-CSF autoantibodies in 5 of 7 patients studied with central nervous system nocardiosis and in no healthy controls (n = 14). GM-CSF production was induced by Nocardia in vitro, suggesting a causative role for anti-GM-CSF autoantibodies in Nocardia susceptibility and dissemination.

CONCLUSIONS

In previously healthy adults with otherwise unexplained disseminated/extrapulmonary Nocardia infections, anti-GM-CSF autoantibodies should be considered. Their presence may suggest that these patients may be at risk for later development of pulmonary alveolar proteinosis or other opportunistic infections, and that patients may benefit from therapeutic GM-CSF administration.