Clinical-pathological and immunohistochemical evaluations of cardiac lesions in cats with chronic kidney disease

Cid, Gabriela C.; Jardim, Mariana P.B.; Jesus, Amanda C.; Costa, Samay Z.R.; Gonçalves, Ilka N.; Peixoto, Tiago C.; Souza, Heloisa J.M.; Nogueira, Vivian A.

doi:10.1590/1678-5150-PVB-6739

ABSTRACT:

Chronic kidney disease (CKD) is characterized by irreversible morphostructural lesions that can progressively evolve to chronic renal insufficiency and kidney failure. It is known that the heart and kidneys are closely related, and that communication between these organs occurs through a variety of pathways; subtle physiological changes in one of them are compensated by the other. Histopathological cardiac evaluation through routine staining presents a limitation to identify specific or discreet lesions in the cardiomyocytes. This study aimed to evaluate serum troponin levels in cats with CKD, associated with clinical and pathological findings, as well as to correlate the morphostructural cardiac lesions to determine their distribution through macroscopic and histological assessments and anti-cardiac troponin C (cTnC) immunohistochemistry (IHC). To this end, 20 cats (18 diagnosed with CKD and two controls) were selected. Anti-human cTnC IHC was conducted after necropsy and separation in eight regions of each collected heart. Heart fragments from two cats without CKD were used as controls. The anti-human cTnC antibody is useful in detecting cardiac lesions and has shown decreased expression in cardiomyocytes of cats with CKD. Serum troponin was above the reference values in 11/18 (61.11%) animals and decreased expression for the cTnC antibody was observed in individual cardiomyocytes in 9/18 (50%) animals. It was verified that the number of regions with decreased expression for the cTnC antibody in cardiomyocytes is significantly correlated with serum troponin. The anti-human cTnC antibody has been found effective in detecting cardiac lesions and has shown decreased expression in the cardiomyocytes of cats with CKD. Correlation was observed between increased serum cTnI and loss of immunoreactivity at anti-cTnC antibody IHC in cats with CKD, which proves damage to cardiomyocytes secondary to kidney disease.

INDEX TERMS:
Clinics; pathology; immunohistochemistry; cardiac lesions; cats; renal disease; troponin; biomarker; cardiology; nephrology

[1] *Corresponding author: gabrieladecarvalhocid@gmail.com

Cat	IRIS stage	Creatinine 0.51.6mg/dL (reference)	Urea 42.854.2mg/dL (reference)	Troponin serum 0.030.16ng/L (reference)	Cardiac lesion (HE)	Areas with troponin loss (IHC)
1	II	2.0	53.0	0.03	No	No
2	III	2.91	72.7	0.09	Yes	(+)
3	IV	13.0	130.0	0.673	No	No
4	IV	6.81	308.2	39,497	Yes	+++
5	IV	6.6	152	0.11	No	No
6	IV	11.3	430.6	0.120	No	No
7	II	2.2	188.5	1,558	Yes	(+)
8	IV	6.33	206.1	0.448	Yes	(+)
9	IV	6.8	226	0.990	Yes	(+)
10	IV	8.8	241	0.085	No	No
11	IV	8.2	325	0.023	No	No
12	IV	17.0	276.0	0.166	No	No
13	II	2.8	-	9,332	Yes	(+)
14	IV	8.40	226	1,237	Yes	(+)
15	IV	9.4	276	51,019	Yes	+++
16	IV	8.0	200.0	0.046	No	No
17	IV	10.9	309	0.206	Yes	(+)
18	II	2.8	47	0.131	No	No
19*	-	-	-	-	No	No
20*	-	1.6	-	0.11	No	No

Laboratory tests	Spearman’s correlation	p-value	N
Maximum creatinine	-0.1203	0.6345	18
Maximum urea	0.2015	0.4381	17
Hematocrit	0.1797	0.4900	17
Leukogram	0.1966	0.4656	16
Troponin	0.7754	0.0002	18
Creatinine 1	0.1101	0.6636	18
Creatinine 2	-0.2848	0.3457	13
Creatinine 3	-0.2062	0.6242	8
Creatinine 4	-0.2236	0.7177	5
Creatinine 5	-1,0000	1,0000	2
Urea 1	0.3243	0.2041	17
Urea 2	-0.1927	0.5938	10
Urea 3	-0.4743	0.4195	5
Urea 4	0	1,0000	3
Urea 5	*	*	1

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Brasil

Clinical-pathological and immunohistochemical evaluations of cardiac lesions in cats with chronic kidney disease

Avaliações clínico-patológica e imuno-histoquímica de lesões cardíacas em gatos com doença renal crônica

ABSTRACT: