Canadian Journal of Kidney Health and Disease最新文献

Rationale: Hemophagocytic lymphohistiocytosis (HLH) is a life-threatening disease characterized by excessive immune activation. It is more commonly seen in children but increasingly recognized in adults. Primary HLH relies on a genetic predisposition, whereas secondary HLH develops in the context of infections, malignancies, or autoimmune diseases. Hemophagocytic lymphohistiocytosis has been rarely described in patients on immunosuppressive therapy after kidney transplant. Here, we describe a case of HLH in a patient with a remote history of kidney transplant, triggered by a viral infection.

Presenting concerns: A 45-year-old female, with a kidney transplant in 2009 for IgA nephropathy, presented with fever, vomiting, and back pain of 1-week duration. She was on triple immunosuppression consisting of daily doses of prednisone 5 mg, azathioprine 100 mg, and tacrolimus extended release 1 mg, and a baseline creatinine of 130 µmol/L.

Diagnosis: Initial investigations showed anemia, leukopenia, elevated serum creatinine, transaminitis, and markedly increased ferritin of 67 600 µg/L which prompted a bone marrow biopsy to rule out HLH. The bone marrow showed an increased proportion of CD68+ cells (macrophages) with more than 5 in 1000 hemophagocytic macrophages. Her soluble IL-2 receptor (CD25) level was 3406 pg/mL (606-2299 pg/mL) which was mildly elevated. She fulfilled 4 of the 8 criteria for HLH and with an H score was 223 which suggested a diagnosis of HLH with 96.9% probability. An extensive secondary workup for possible triggers for HLH led to a swab from genital ulcers that was positive for herpes simplex virus (HSV) type 2. The polymerase chain reaction (PCR) in the blood for HSV type 2 was also positive.

Interventions: Given the diagnosis of HSV type 2 as the putative trigger for HLH, she was started on parenteral acyclovir for 2 weeks followed by oral valacyclovir for 2 more weeks. In the context of infection, the azathioprine was stopped while low-dose steroid and tacrolimus were continued.

Outcomes: With the initiation of treatment for HSV infection, leukopenia, creatinine, and transaminases improved along with ferritin levels. At her 6-month follow-up, her blood counts and liver enzymes had normalized, and ferritin was 566 µg/L.

Teaching points: Hemophagocytic lymphohistiocytosis is a rare disease in kidney transplant recipients with a high mortality rate. It can occur even in remote kidney transplant recipients so a high degree of suspicion is necessary to lead to a prompt diagnosis. Infections are common triggers for secondary HLH. Early identification and treatment of the triggering infection may improve outcomes.

Historically, it takes an average of 17 years to move new treatments from clinical evidence to daily practice. Given the highly effective treatments now available to prevent or delay kidney disease onset and progression, this is far too long. The time is now to narrow the gap between what we know and what we do. Clear guidelines exist for the prevention and management of common risk factors for kidney disease, such as hypertension and diabetes, but only a fraction of people with these conditions worldwide are diagnosed, and even fewer are treated to target. Similarly, the vast majority of people living with kidney disease are unaware of their condition, because in the early stages, it is often silent. Even among patients who have been diagnosed, many do not receive appropriate treatment for kidney disease. Considering the serious consequences of kidney disease progression, kidney failure, or death, it is imperative that treatments are initiated early and appropriately. Opportunities to diagnose and treat kidney disease early must be maximized beginning at the primary-care level. Many systematic barriers exist, ranging from patient to clinician to health systems to societal factors. To preserve and improve kidney health for everyone everywhere, each of these barriers must be acknowledged so that sustainable solutions are developed and implemented without further delay.

Background: Although blood pressure (BP) control is critical to prevent cardiovascular diseases, hypertension control rates in Canada are in decline.

Objective: To assess this issue, we sought to evaluate the differences in antihypertensive medication prescription profiles in the province of Quebec between 2009 and 2021.

Design: This is a retrospective cohort study.

Setting: We used data from the CARTaGENE population-based cohort linked to administrative health databases.

Patients: Participants with any drug claim in the 6 months prior to the end of follow-up were included.

Measurements: Guideline-recommended antihypertensive drug prescription profiles were assessed at the time of enrollment (2009-2010) and end of follow-up (March 2021).

Methods: Prescriptions practices from the 2 time periods were compared using Pearson's chi-square tests. A sensitivity analysis was performed by excluding participants in which antihypertensive drugs may not have been prescribed solely to treat hypertension (presence of atrial fibrillation/flutter, ischemic heart disease, heart failure, chronic kidney disease, or migraines documented prior to or during follow-up).

Results: Of 8447 participants included in the study, 31.4% and 51.3% filled prescriptions for antihypertensive drugs at the beginning and end of follow-up. In both study periods, guideline-recommended monotherapy was applied in most participants with hypertension (77.9% vs 79.5%, P = .3), whereas optimal 2 and 3-drug combinations were used less frequently (62.0% vs 61.4%, P = .77, 51.9% vs 46.7%, P = .066, respectively). Only the use of long-acting thiazide-like diuretics (9.5% vs 27.7%, P < .001) and spironolactone as a fourth-line agent (8.3% vs 15.9%, P = .054) increased with time but nonetheless remained infrequent. Results were similar in the sensitivity analysis.

Limitations: Specific indication of the prescribed antihypertensive medications and follow-up BP data was not available.

Conclusions: Application of hypertension guidelines for the choice of antihypertensive drugs remains suboptimal, highlighting the need for education initiatives. This may be an important step to raise BP control rates in Canada.