A 17-year-old girl with lower extremity rash and acute kidney injury is actually because she is too loving?

*For medical professionals to read and reference The more complicated the case, the more the reason behind it is worth investigating! With complex immunological manifestations and confusing sources of infection, what is wrong with this young girl in bloom? Today, let's learn about this rare case published in the BMC Journal of Rheumatology! It's definitely an infection, but where is the source of the infection? Infected what? A 17-year-old female patient was admitted to the emergency department with a vasculitic rash of the lower extremities
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 The medical history was taken and it was revealed that the patient underwent surgery (using an 18 mm Contegra catheter) for pulmonary atresia and ventricular septal defect at the age of 4 years, and began to experience unexplained loss of appetite and weight loss (14 kg) in the past year
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Emergency urinalysis showed that the patient had acute blood proteinuria, serum creatinine of 128 μmol/L, spleen enlargement (19 cm), and ANCA PR3 was weakly positive in the initial immune test, suggesting the possibility of ANCA-related vasculitis
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Blood test showed: decreased complement C4 (0.
09g/L), increased IgG (45.
05g/L), increased IgM (3.
25g/L), positive rheumatoid factor: 211
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The rest of the indicators are shown in the figure below
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Fig.
1 The results of blood test of the patientFig.
2 The classification of cryoglobulinemia considers the possibility of cryoglobulinemia and acute infection
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Because the patient may have acute kidney injury, the hospital performed a kidney biopsy
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RESULTS: Focal segmental hyperplastic and necrotic lesions with double contours and cellular fibrous crescents, normal tubulointerstitium, and no acute tubular necrosis or chronic changes
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Immunofluorescence showed C3 (3+), Lambda (2+), IgM (1+), C1q (+/-)
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Immune complexes were seen in paramesangial, mesangial, and subepithelial sites
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These biopsy features were consistent with infection-related membranoproliferative glomerulonephritis
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 Figure 3.
Results of renal biopsy of the patient.
Whether it is blood test or renal biopsy, the etiology of this patient is pointed to infection, but where is the infection focus? Considering that the patient had undergone cardiac catheterization, the possibility of catheter degeneration and infection was considered
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A PET scan showed an infectious or inflammatory etiology around the ductal valve, and CT pulmonary angiography also showed a septic embolus in the anterior basal layer of the right lower lobe of the lung
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 Since then, the patient's diagnosis has been completely clear: cryoglobulinemia, infection-associated membranous proliferative glomerulonephritis, and infective endocarditis
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 The infection focus is basically determined.
Considering that 13 years have passed since the patient's catheter operation, the doctor used vancomycin, gentamicin and rifampicin for combined anti-infective treatment based on experience
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But two weeks of antibiotic treatment did not bring about a resolution of inflammation, and the patient's kidney function still did not recover
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 This is more complicated, is it some uncommon pathogen infection? Histology Chain is actually the "pot" of stray cats? In order to identify the source of infection as soon as possible and remove inflammatory vegetations on the patient's catheter, the doctor transferred her to the Cardiac Surgery Department for catheter repair surgery, and the surrounding tissue was screened for pathogens
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The results showed positive for Bartonella
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 Bartonella is a zoonotic pathogen
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Domestic cattle, dogs, cats and any wild animals as well as humans can serve as their final hosts, and arthropods such as flies, fleas, lice, and lacewings are their storage hosts [2]
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After asking the patient's mother, the doctor learned that the patient started adopting stray cats at home a year ago
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From this, the source of infection of the patient can be determined
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 After doxycycline + antifungal + oral steroid therapy, the patient's cryoglobulinemia was relieved, and renal function, rheumatoid factor, and complement C4 were gradually normalized
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After 6 months of follow-up, the patient's appetite improved, splenomegaly subsided, creatinine recovered to 51 μmol/l, and blood was detected for cryoglobulin (-)
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 Case study: In case of unexplained infection, don't miss life history inquiry! Treating and rescuing stray animals is a show of love, but this case sounded the alarm for everyone, and also reminded medical staff.
When encountering infected patients with complicated conditions, remember to ask about the contact history of stray animals! In recent years, the incidence of Bartonella infection in humans mentioned in this case has increased.
Among the 27 known Bartonella species, 8 can cause endocarditis after infection, originally suffering from heart disease, valvular disease and Immunocompromised people are more susceptible to disease [3]
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In addition, people infected with Bartonella often have a history of close contact with wild animals or a history of scratching by dogs and cats
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In fact, the endocarditis caused by Bartonella was reported as early as 1993, but the endocarditis caused by Bartonella has great variability and complex clinical manifestations, and laboratory bacterial culture is still used as the basis for diagnosis
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This case is the first case of Bartonella-associated endocarditis with cryoglobulinemia in the UK [1]
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  Figure 4 How Bartonella can be transmitted from cats to humans Compared with endocarditis, Bartonella infection is more common with cutaneous manifestations—maculopapular rash, papules, subcutaneous nodules, and lymphadenopathy are the most common, while febrile measles, purpura, urticaria Measles, erythema nodosum, erythema multiforme, and granuloma annulare may all be associated with Bartonella infection [4]
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Figure 5.
Some skin manifestations of Bartonella infection (from top to bottom: bacillary hemangioma, cutaneous vasculitis, granuloma annulare) Although the clinical manifestations of Bartonella infection are complex, the treatment is actually relatively simple
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If it is determined to be Bartonella infection, doxycycline [2–4 mg/(kg d)] for 6 weeks + oral gentamicin [3 mg/(kg d)] for 2 weeks can be used, and the prognosis is generally good [3] ]
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Unfortunately, there is currently no effective way to prevent Bartonella infection
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In order to avoid Bartonella infection, regular environmental sterilization, pet deworming, avoiding pet scratches and improving self-immunity cannot be ignored
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 Reference [1] Vivekanantham, A.
, Patel, R.
, Jenkins, P.
et al.
A “cat”-astrophic case of Bartonella infective endocarditis causing secondary cryoglobulinemia: a case report.
BMC Rheumatol 6, 16 (2022).
https://doi.
org/10.
1186/s41927-022-00248-0[2] Chen Qi, Xia Luming, Yu Xiangqian, et al.
Research progress on feline Bartonellosis and cat scratch disease [J].
Advances in Animal Medicine, 2011 , 32(001):73-76.
[3] Liu Yunyan, Li Dongmei, Liu Qiyong, et al.
Research progress of Bartonella infective endocarditis [J].
Bulletin of Microbiology, 2015, 42(1):8.
[ 4] Lins, Karina de Almeida et al.
“Cutaneous manifestations of bartonellosis.
” Anais brasileiros de dermatologia vol.
94,5 (2019): 594-602.
doi:10.
1016/j.
abd.
2019.
09.
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