Atypical hemolytic uremic syndrome: a case report

BACKGROUND

Thrombotic microangiopathy is a pathological condition comprised of microvascular thrombosis involving any organ of the body leading to thrombocytopenia, Coombs-negative hemolytic anemia, and end-organ damage. The most common forms of thrombotic microangiopathies are Shiga toxin-producing Escherichia coli-mediated hemolytic uremic syndrome, thrombotic thrombocytopenic purpura, and atypical hemolytic uremic syndrome. The atypical hemolytic uremic syndrome occurs due to genetic and acquired mutations in complement regulatory factors and to complement activation factors in the immune system, mainly the alternative pathway. Clinical manifestations and outcomes differ with the prevalent mutations of the patient. Currently, available treatment modalities are therapeutic plasma exchange and a monoclonal antibody against C5, eculizumab. We report a case of a Sri Lankan girl diagnosed with atypical hemolytic uremic syndrome complicated with septicemia, hemolytic anemia, acute kidney injury, pulmonary hemorrhage with respiratory failure, and hypertension who had a complete remission following long-term (30 months) therapeutic plasma exchange.

CASE PRESENTATION

A 15-year-old Sri Lankan girl was transferred from a local hospital with the features of septicemia and acute kidney injury for specialized management. She had high blood pressure (180/100 mmHg) on admission. She underwent appendicectomy based on suspicion of acute appendicitis as the cause of sepsis. Following surgery, her condition deteriorated, and intensive care unit management was warranted because she developed pulmonary hemorrhages and respiratory failure requiring mechanical ventilation and renal replacement therapy in the form of hemodialysis. Her blood investigations showed microangiopathic hemolytic anemia, thrombocytopenia, elevated lactate dehydrogenase, and reduced human complement C3 levels, together with a normal coagulation profile. She was diagnosed with atypical hemolytic uremic syndrome and was initiated on therapeutic plasma exchange and other supportive therapy, including corticosteroids. Following a lengthy course of plasma exchange, complete recovery was achieved.

CONCLUSION

The atypical hemolytic uremic syndrome is a rare disease entity requiring a high index of suspicion to diagnose. It is a diagnosis of exclusion. Early diagnosis with prompt treatment will render a better outcome. The atypical hemolytic uremic syndrome needs to be considered in all patients with thrombotic microangiopathy.

Prospective Biopsy-Based Study of CKD of Unknown Etiology in Sri Lanka

BACKGROUND AND OBJECTIVES

A kidney disease of unknown cause is common in Sri Lanka's lowland (dry) region. Detailed clinical characterizations of patients with biopsy-proven disease are limited, and there is no current consensus on criteria for a noninvasive diagnosis.

DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS

We designed a prospective study in a major Sri Lankan hospital servicing endemic areas to ascertain pathologic and clinical characteristics of and assess risk factors for primary tubulointerstitial kidney disease. We used logistic regression to determine whether common clinical characteristics could be used to predict the presence of primary tubulointerstitial kidney disease on kidney biopsy.

RESULTS

From 600 new patients presenting to a tertiary nephrology clinic over the course of 1 year, 87 underwent kidney biopsy, and 43 (49%) had a biopsy diagnosis of primary tubulointerstitial kidney disease. On detailed biopsy review, 13 (30%) had evidence of moderate to severe active kidney disease, and six (15%) had evidence of moderate to severe chronic tubulointerstitial kidney disease. Patients with tubulointerstitial kidney disease were exclusively born in endemic provinces; 91% spent a majority of their lifespan there. They were more likely men and farmers (risk ratio, 2.0; 95% confidence interval, 1.2 to 2.9), and they were more likely to have used tobacco (risk ratio, 1.7; 95% confidence interval, 1.0 to 2.3) and well water (risk ratio, 1.5; 95% confidence interval, 1.1 to 2.0). Three clinical characteristics-age, urine dipstick for protein, and serum albumin-could predict likelihood of tubulointerstitial kidney disease on biopsy (model sensitivity of 79% and specificity of 84%). Patients referred for kidney biopsy despite comorbid diabetes or hypertension did not experience lower odds of tubulointerstitial kidney disease.

CONCLUSIONS

A primary tubulointerstitial kidney disease occurs commonly in specific regions of Sri Lanka with characteristic environmental and lifestyle exposures.

Expanding CAPD in Low-Resource Settings: A Distance Learning Approach

BACKGROUND

Despite growing need, treatment for end-stage renal disease is limited in low- and middle-income countries due to resource restraints. We describe the development of an educational curriculum and quality improvement program to support continuous ambulatory peritoneal dialysis (CAPD) performed primarily by non-nephrology providers in Sri Lanka.

METHODS

We developed a program of education, outcome tracking, and expert consultation to support providers in Kandy, Sri Lanka. Education included videos and in-person didactics covering core topics in CAPD. Event-tracking sheets recorded root causes and management of infections and hospitalizations. Conferences reviewed clinical cases and overall clinic management. We evaluated the patient census, peritonitis rates, and root causes and management of infections over 1 year.

RESULTS

The curriculum was published through the International Society of Nephrology online academy. High provider turnover limited curriculum assessments. The CAPD patient census rose from 63 to 116 during the year. The peritonitis rate declined significantly, from 0.8 episodes per patient-year in the first 6 months to 0.4 in the latter 6 months, though the most common root causes of peritonitis, related to contamination events and hygiene, persisted. The appropriate ascertainment of culture data and prescription of antibiotics also increased.

CONCLUSIONS

Our project supported the expansion of a CAPD program in a resource-limited setting, while also improving peritonitis outcomes. Ongoing challenges include ensuring a durable educational system for rotating providers, tracking outcomes beyond peritonitis, and formalizing management protocols. Our program can serve as an example of how established dialysis programs can support the burgeoning work of providers in resource-limited setting.