Acute Tubulointerstitial Nephritis in Legionnaires' Disease
Acute Tubulointerstitial Nephritis in Legionnaires' Disease
A 55-year-old Caucasian man was admitted to the Nephrology Department at our institution for ARF diagnosed in the emergency room along with left-sided, community-acquired pneumonia. He was on oral anti-diabetic treatment for uncomplicated type 2 diabetes and was a cigarette smoker. He reported no recent use of non-steroidal anti-inflammatory drugs or antibiotics.
Clinical examination revealed that his temperature was 38°C and his blood pressure was 120/60 mmHg. His urinary output was diminished and concentrated. Pulmonary examination revealed diffuse crackles of the left lung accompanied by a dry, irritative cough and exertional dyspnea. The rest of the patient's examination was normal.
Chest X-ray revealed alveolar opacities in the left lung. No sputum could be obtained for culture, but his test for Legionella antigenuria was positive. Antibiotic therapy with erythromycin and ofloxacin was initiated.
Blood tests revealed elevated serum creatinine (614 μmol/L; normal range, 62 to 106 μmol/L), blood urea nitrogen (28 mmol/L; normal range, 2.14 to 7.14 mmol/L) and C-reactive protein (360 mg/L; normal range, 0 to 3 mg/L) with leukocytosis (13 g/L; normal range, 4 to 11 g/L). No anemia or thrombocytopenia was noted, and the patient's liver function tests were normal. The patient had elevated levels of lactate dehydrogenase (408 IU/L; normal range, 135 to 225 IU/L) and creatine phosphokinase (CPK) (2000 IU/L; normal range, 47 to 171 IU/L). At room air, his arterial blood gas was pH 7.44 (normal range, 7.35 to 7.45), partial pressure of carbon dioxide was 29 mmHg (normal range, 35 to 45 mmHg) and partial pressure of oxygen was 65 mmHg (normal range, 80 to 100 mmHg) with HCO3 of 22 mmol/L (normal range, 20 to 25 mmol/L).
Analysis of the urinary sediment revealed aseptic leukocyturia (684/mm; normal range, < 20/mm) and hematuria (56/mm; normal range, 0 to 10/mm). The patient's urinary sodium was below 20 mmol/L, urinary urea was 13 g/L and proteinuria was 2.48 g/L (normal range, 0 to 0.3 g/L) with albuminuria of 0.4 g/L (normal range, < 0.03 g/L). His renal ultrasound was normal.
Although our patient's respiratory signs and chest X-ray revealed improvement with antibiotics, his ARF worsened despite saline solute infusion, and he became anuric. His serum creatinine level at day 3 was 1000 μmol/L. Hemodialysis was initiated with a central jugular catheter.
Percutaneous renal biopsy was performed at day 4, which showed acute TIN (Figures 1 and 2) with interstitial edema and inflammatory peritubular infiltrate composed of lymphocytes and plasma cells. No proliferation or deposit was noted on the 21 glomeruli examined. Under immunofluorescence, only immunoglobulin-secreting plasma cells were visible.
(Enlarge Image)
Figure 1.
Renal biopsy. Renal biopsy showing interstitial cell infiltrate associated with edema and few tubules lined by flattened cells. No granuloma was observed. Masson trichrome stain; original magnification, ×100.
(Enlarge Image)
Figure 2.
Renal biopsy. Renal biopsy showing focal tubulitis with mononuclear cells that have invaded few tubules. No granuloma was observed. Masson trichrome stain; original magnification, ×200.
The patient's blood cultures were normal, his bacterial and viral serologies were negative (leptosirosis, human immunodeficiency virus (HIV), hepatitis B virus and hepatitis C virus), the search for tuberculosis and autoimmunity was negative (normal complement level, negative anti-nuclear antibodies and anti-SSA/SSB) and his eye examination was normal. Therefore, we attributed his acute TIN to LD.
Steroid treatment was initiated at 1 mg/kg/day. The patient's renal function rapidly improved, with appropriate diuresis allowing for withdrawal of hemodialysis after 2 days. There was no worsening of respiratory signs under steroid treatment. The patient was discharged at day 10, at which time his serum creatinine level was 110 μmol/L. One month later, after cessation of steroids and antibiotics, his serum creatinine level was 77 μmol/L. Investigation by Health Services did not find the source of Legionella contamination.
Case Presentation
A 55-year-old Caucasian man was admitted to the Nephrology Department at our institution for ARF diagnosed in the emergency room along with left-sided, community-acquired pneumonia. He was on oral anti-diabetic treatment for uncomplicated type 2 diabetes and was a cigarette smoker. He reported no recent use of non-steroidal anti-inflammatory drugs or antibiotics.
Clinical examination revealed that his temperature was 38°C and his blood pressure was 120/60 mmHg. His urinary output was diminished and concentrated. Pulmonary examination revealed diffuse crackles of the left lung accompanied by a dry, irritative cough and exertional dyspnea. The rest of the patient's examination was normal.
Chest X-ray revealed alveolar opacities in the left lung. No sputum could be obtained for culture, but his test for Legionella antigenuria was positive. Antibiotic therapy with erythromycin and ofloxacin was initiated.
Blood tests revealed elevated serum creatinine (614 μmol/L; normal range, 62 to 106 μmol/L), blood urea nitrogen (28 mmol/L; normal range, 2.14 to 7.14 mmol/L) and C-reactive protein (360 mg/L; normal range, 0 to 3 mg/L) with leukocytosis (13 g/L; normal range, 4 to 11 g/L). No anemia or thrombocytopenia was noted, and the patient's liver function tests were normal. The patient had elevated levels of lactate dehydrogenase (408 IU/L; normal range, 135 to 225 IU/L) and creatine phosphokinase (CPK) (2000 IU/L; normal range, 47 to 171 IU/L). At room air, his arterial blood gas was pH 7.44 (normal range, 7.35 to 7.45), partial pressure of carbon dioxide was 29 mmHg (normal range, 35 to 45 mmHg) and partial pressure of oxygen was 65 mmHg (normal range, 80 to 100 mmHg) with HCO3 of 22 mmol/L (normal range, 20 to 25 mmol/L).
Analysis of the urinary sediment revealed aseptic leukocyturia (684/mm; normal range, < 20/mm) and hematuria (56/mm; normal range, 0 to 10/mm). The patient's urinary sodium was below 20 mmol/L, urinary urea was 13 g/L and proteinuria was 2.48 g/L (normal range, 0 to 0.3 g/L) with albuminuria of 0.4 g/L (normal range, < 0.03 g/L). His renal ultrasound was normal.
Although our patient's respiratory signs and chest X-ray revealed improvement with antibiotics, his ARF worsened despite saline solute infusion, and he became anuric. His serum creatinine level at day 3 was 1000 μmol/L. Hemodialysis was initiated with a central jugular catheter.
Percutaneous renal biopsy was performed at day 4, which showed acute TIN (Figures 1 and 2) with interstitial edema and inflammatory peritubular infiltrate composed of lymphocytes and plasma cells. No proliferation or deposit was noted on the 21 glomeruli examined. Under immunofluorescence, only immunoglobulin-secreting plasma cells were visible.
(Enlarge Image)
Figure 1.
Renal biopsy. Renal biopsy showing interstitial cell infiltrate associated with edema and few tubules lined by flattened cells. No granuloma was observed. Masson trichrome stain; original magnification, ×100.
(Enlarge Image)
Figure 2.
Renal biopsy. Renal biopsy showing focal tubulitis with mononuclear cells that have invaded few tubules. No granuloma was observed. Masson trichrome stain; original magnification, ×200.
The patient's blood cultures were normal, his bacterial and viral serologies were negative (leptosirosis, human immunodeficiency virus (HIV), hepatitis B virus and hepatitis C virus), the search for tuberculosis and autoimmunity was negative (normal complement level, negative anti-nuclear antibodies and anti-SSA/SSB) and his eye examination was normal. Therefore, we attributed his acute TIN to LD.
Steroid treatment was initiated at 1 mg/kg/day. The patient's renal function rapidly improved, with appropriate diuresis allowing for withdrawal of hemodialysis after 2 days. There was no worsening of respiratory signs under steroid treatment. The patient was discharged at day 10, at which time his serum creatinine level was 110 μmol/L. One month later, after cessation of steroids and antibiotics, his serum creatinine level was 77 μmol/L. Investigation by Health Services did not find the source of Legionella contamination.
