#1061 Brucella infection in a patient with renal cystic disease and renal imaging changes before and after treatment: a case report
Authors: Xue Zhuorui 
Published: May 2024

Background and Aims

Brucellosis can affect nearly all systems. Genitourinary involvement is uncommon in patients with brucellosis, accounting for approximately 10% of cases. We diagnosed a rare case of renal cysts with brucellosis and reported renal imaging changes before and after treatment.

Method

A 38-year-old man was admitted to our hospital in September 2021 with complaints of elevated serum creatinine, proteinuria for more than 2 months, and intermittent fever for 2 weeks. In July 2020, the patient experienced fatigue, and a rash on all four extremities. He denied experiencing low back pain or joint swelling. Urine analysis revealed the following: BLD (+), Pro (+), 24-hour urine protein (24 h UP) 0.7 g; blood: Cr 11.88 mg/dL, UA 77.51 mg/dL, ALP 217 IU/L, and GGT 227 IU/L. MRI revealed multiple small punctate areas with short T1 signals in both kidneys and splenomegaly. Soon, he experienced persistent afternoon fever with a maximum temperature of 39.0°C, along with night sweats and left lumbar pain. There were no symptoms of cough, expectoration, or urinary tract irritation. The patient had diabetes mellitus and diabetic retinopathy. He has lived in the Inner Mongolia Autonomous Region. He denied having any contact with raw milk or mice. His father and sister had kidney disease and diabetes. In September 2021, the patient was admitted to our hospital. Urinalysis revealed BLD (-), Pro 0.3 g/L, and 24 hUP 1.39 g; blood: HGB 117 g/L, ALP 227 U/L, GGT 221 U/L, Cr 2.56 mg/dL, UA 88.79 mg/dL, and K 3.2 mEq/L. The infection indicators were as follows: the standard tube agglutination test (+) (Fig. 1), Brucella (+) in blood culture, a positive qualitative test for blood cryptococcal antigen and qualitative positive results for 6 Cryptococcus neoformans sequences in bronchoalveolar lavage fluid using next-generation sequencing. Ultrasound showed multiple cysts in both kidneys. It also showed uneven echogenicity in the left testis and visible lymph nodes in the left neck, bilateral axillae and groin. CT revealed cavitary nodules and ground-glass opacities in the right middle lobe, as well as splenomegaly. MRI revealed renal cysts (Fig. 2a, b, c) and abscesses (Fig. 2e, f, g). The patient was diagnosed with stage 3 chronic kidney disease (CKD), pulmonary cryptococcosis, and brucellosis associated with renal abscess, left orchitis, splenomegaly, multiple lymphadenopathies, rash, and hyperuricemia. Doxycycline, rifampicin, and fluconazole were administered. He had no fever, his low back pain had disappeared, and his rash were relieved.

Results

A reexamination after 2 months revealed the following: the urinalysis results revealed a BLD (-), Pro(-), and 24 hUP 0.15 g; blood: GGT 107 IU/L; ALP 72 IU/L; Cr 1.89 mg/dL; UA 0.22 mg/dL; and K 4.0 mEq/L. Ultrasound revealed a decrease in the size of the spleen. MRI revealed the liquefaction of renal abscesses. Brucella therapy has been found to be effective.

Conclusion

The patient was a young man who was infected with both Brucella and Cryptococcus. Although his hometown was in an area affected by an epidemic, his current residence was not affected. Namely, he was immunocompromised, which was associated with diabetes. After receiving anti-Brucella treatment, his symptoms disappeared, the renal abscess liquefied, but creatinine decreased to levels similar to those at onset without a decreasing trend. These findings suggest that the patient had underlying CKD that was not associated with Brucellosis. We believe that the CKD was diabetes and renal cysts. He had hyperuricemia, hypomagnesaemia, unexplained asymptomatic abnormal liver function, and mild proteinuria. Imaging indicated the presence of renal cysts. In addition to having diabetes, he had a family history of kidney disease and diabetes. We diagnosed the patient with CKD and as having autosomal dominant tubulointerstitial disease (ADTKD) associated with the HNF1B pathogenic gene mutation. This gene mutation is also rare in ADTKD patients. Genetic testing revealed that the causative genes include NM001303448. Potential causative genes included NM000128. The mutated genes mentioned above are not typical causative genes for HNF1B or other types of ADTKD.