Children With Lupus Nephritis Complicated With Pneumonia:A Report Of Two Cases And Review Of The Literature

Objective:Lupus nephritis(LN)is one of the most common complications of systemic lupus erythematosus(SLE).Glucocorticoids and immunosuppressants are the main drugs for the treatment of LN.Glucocorticoids and immunosuppressants used in the treatment of LN give rise to a tendency for infectious pneumonia.The incidence of infectious pneumonia was 30%in patients with LN.It is the main cause of death in children with LN and the mortality rate is nearly 50%.It is difficult to distinguish between infectious pneumonia and lupus interstitial lung disease.We report two cases of children with LN complicated with pneumonia,in which lung biopsy pathology and bronchoalveolar lavage fluid(BLAF)metagenomic next-generation sequencing(m NGS)were performed in addition to clinical manifestations,laboratory tests and imaging examinations.Patient&Methods:The clinical date of two patients with LN,one girl and one boy,were collected.Both of them were 13 years old.They were admitted to Department of Pediatrics,Fuzong Clinical Medical College of Fujian Medical University for chest pain in Patient 1 and fever with cough in Patient 2.We asked for a medical history of the children and performed a medical examination.Arterial blood gas analysis,complete blood count,urinalysis,blood biochemistry,C-reactive protein,procalcitonin,C3 levels,C4 levels,autoantibodies,the antibodies of serum respiratory viruses,pathogens such as Epstein-Barr virus and cytomegalovirus,tuberculosis antibody,serum(1,3)-β-D-glucan test(G test),serum galactomannan test(GM test),blood culture,sputum culture and urine culture were detected,and chest high-resolution computed tomography(HRCT),pathogen detection and m NGS of BLAF were performed.Patient 1 had a lung biopsy.The follow-up period is one month.We comprehensively analyzed the clinical manifestations,laboratory test results,imaging examinations,lung pathology,BLAF routine pathogen detections and m NGS results and related literature review.Results:The two patients were classified as SLE with a score of 33 and 25,respectively.Their renal pathologies were consistent with LN of Class IV(A/C).They were diagnosed with SLE and LN based on the latest diagnostic criteria for SLE.Their SLEDAI-2000 scores were 18 points.They were underwent a diagnostic bronchoscopy with alveolar lavage,pathogen detection and m NGS of BLAF were performed.Patient 1 had CT-guided percutaneous needle lung biopsy and was diagnosed as fibrin exudates and neutrophils in alveolar space in pathology.In Patient 1,lung biopsy tissues m NGS showed the number of sequences in the nocardia was 5335,the copies of BLAF mycoplasma pneumoniae DNA were3.97×10~4,BLAF m NGS showed the number of sequences in the mycoplasma pneumoniae was 6 and the number of sequences in the pneumocystis jirovecii was2.These results suggested that nocardia,pneumocystis jirovecii and mycoplasma pneumoniae were positive.She was diagnosed with LN complicated with pneumonia.Patient 1 was treated with ceftriaxone,compound sulfamethoxazole,azithromycin and fluconazole.In Patient 2,the copies of BLAF mycoplasma pneumoniae DNA were 2.25×10~5,the copies of BLAF cytomegalovirus DNA were3.97×10~4,BLAF m NGS showed the number of sequences in the mycoplasma pneumoniae was 25 and the number of sequences in the pneumocystis jirovecii was49.These results suggested that mycoplasma pneumoniae,pneumocystis jirovecii and cytomegalovirus were positive.He was diagnosed with LN complicated with pneumonia.Patient 2 was given azithromycin,moxifloxacin,ganciclovir,ompound sulfamethoxazole and fluconazole.The two patients’symptoms improved with the above treatments.Their SLEDAI-2000 scores were decreased to 8 points.Conclusions:Both of LN complicated with infectious pneumonia and lupus interstitial lung disease showed similar clinical manifestations and imaging changes.When they cannot be distinguished based on clinical manifestations,routine laboratory tests and imaging examinations,lung biopsy pathology examination/BLAF m NGS can be applied to assist in differential diagnosis and guide treatment.