Infection in Patients with Suspected Thrombotic Microangiopathy Based on Clinical Presentation

Assessment of epidemiology and outcomes of adult patients with kidney-limited thrombotic microangiopathies

Thrombotic microangiopathies (TMA) are usually associated with hematological features (RH-TMA). The epidemiology of TMA limited to kidneys (RL-TMA) is unclear Therefore, patients with TMA and native kidney biopsies were identified during 2009-2022 in 20 French hospitals and results evaluated. RL-TMA was present in 341/757 (45%) patients and associated with lower creatinine levels (median 184 vs 346 μmol/L) than RH-TMA. RL-TMA resulted from virtually all identified causes, more frequently from anti-VEGF treatment and hematological malignancies but less frequently from shigatoxin-associated hemolytic uremic syndrome (HUS), systemic sclerosis, gemcitabine and bacterial infection, and even less frequently when three or more causes/triggers were combined (RL-TMA: 5%; RH-TMA: 12%). RL-TMA was associated with significantly lower major cardiovascular events (10% vs 20%), kidney replacement therapy (23% vs 43%) and death (12% vs 20%) than RH-TMA during follow-up (median 28 months). Atypical HUS (aHUS) was found in 326 patients (RL-TMA: 43%, RH-TMA: 44%). Among the 69 patients with proven complement-mediated aHUS, eculizumab (anti-C5 therapy) was used in 43 (62%) (RL-TMA: 35%; RH-TMA: 71%). Among the 257 other patients with aHUS, including 51% with RL-TMA, eculizumab was used in 29 but with unclear effects of this treatment. Thus, RL-TMA represents a very high proportion of patients with TMA and results from virtually all known causes of TMA and includes 25% of patients with complement-mediated aHUS. Adverse outcomes of RL-TMA are lower compared to RH-TMA but remain significant. Anti-C5 therapy was rarely used in RL-TMA, even in proven complement-mediated aHUS, and its effects remain to be assessed.

Thrombotic microangiopathy associated with anticancer and immune system targeting drugs: New insights from real-world data using the WHO pharmacovigilance database

BACKGROUND

The worldwide development of immune system targeting/anticancer drugs has revolutionized immuno-oncology, but their implication in thrombotic microangiopathy syndromes (TMA) is increasingly suspected. Using real-world data, the aim of this study was to identify drugs associated with TMA reporting and to describe the evolution of TMA reporting over time with a focus on these drugs.

METHODS

A global disproportionality study was performed using the individual case safety reports (ICSRs) extracted from the World Health Organization (WHO) pharmacovigilance database (VigiBase) from its inception (1968) to April 30, 2022.

RESULTS

Of the 31,251,040 ICSRs, 6946 cases of suspected drug-induced TMA were included from 55 countries. The outcome was fatal in 18.2% of cases. A total of 72 immune system targeting/anticancer drugs were associated with significant overreporting, including 17 drugs with a potential new safety concern for TMA. Although the rate of TMA reporting per million of ICSRs has remained fairly stable, an absolute increase in reported cases of suspected drug-induced TMA has been observed over the last decade. The pattern of drugs reported in TMA has evolved with a substantial increase in the proportion of cases involving immune system-targeting drugs/anticancer drugs from 47.3% (205/433) in the period 1992-2001 to 80.7% (3819/4730) in the period 2012-2021.

CONCLUSION

Several recently marketed immune system targeting/anticancer drugs have been identified as potential new drugs associated with TMA, which will require confirmatory studies. The number of drugs associated with TMA reporting markedly increased within the past 10 years, primarily due to innovative anticancer drugs.

Thrombotic microangiopathies after kidney transplantation in modern era: nosology based on chronology

BACKGROUND

Thrombotic microangiopathies (TMAs) are rare but can be severe in kidney transplant. recipients (KTR).

METHODS

We analysed the epidemiology of adjudicated TMA in consecutive KTR during the. 2009-2021 period.

RESULTS

TMA was found in 77/1644 (4.7%) KTR. Early TMA (n = 24/77 (31.2%); 1.5% of all KTR) occurred during the first two weeks ((median, IQR) 3 [1-8] days). Triggers included acute antibody-mediated rejection (ABMR, n = 4) and bacterial infections (n = 6). Graft survival (GS) was 100% and recurrence rate (RR) was 8%. Unexpected TMA (n = 31/77 (40.2%); 1.5/1000 patient-years) occurred anytime during follow-up (3.0 (0.5-6.2) years). Triggers included infections (EBV/CMV: n = 10; bacterial: n = 6) and chronic active ABMR (n = 5). GS was 81% and RR was 16%. Graft-failure associated TMA (n = 22/77 (28.6%); 2.2% of graft losses) occurred after 8.8 (4.9-15.5) years). Triggers included acute (n = 4) or chronic active (n = 14) ABMR, infections (viral: n = 6; bacterial: n = 5) and cancer (n = 6). 15 patients underwent transplantectomy. RR was 27%. Atypical (n = 6) and typical (n = 2) haemolytic and uremic syndrome, and isolated CNI toxicity (n = 4) were rare. Two-third of biopsies presented TMA features.

CONCLUSIONS

TMA are mostly due to ABMR and infections; causes of TMA are frequently combined. Management often is heterogenous. Our nosology based on TMA timing identifies situations with distinct incidence, causes and prognosis.